Castilleja
Suppl. Pl., 47, 293. 1782.
Herbs or subshrubs, rarely shrubs, annual or perennial, sometimes biennial; hemiparasitic, caudex woody or fleshy, taprooted to fibrous-rooted or rhizomatous. Stems 1–200, strongly decumbent to erect, sometimes prostrate or sprawling, frequently with leafy axillary shoots, not fleshy, glabrous or pubescent, hairs eglandular or stipitate-glandular, unbranched, rarely ± to much-branched or stellate. Leaves mostly deciduous, cauline, mostly alternate, reduced proximally or forming basal rosettes in a few species; petiole absent or present; blade fleshy or not, leathery or not, margins entire or pinnately to ± palmately divided. Inflorescences terminal, compact to elongate spikes or secund, sometimes non-secund, racemes; bracts present, often brightly colored distally or throughout. Pedicels absent or present; bracteoles absent. Flowers: sepals 4, calyx entirely green or more often conspicuously colored distally, usually as in bracts, contrasting with bracts in a few species, radially or bilaterally symmetric, tubular, lobed distally in usually diagnostic patterns: either cleft into 4 subequal lobes (called segments in some floras), or abaxial and adaxial clefts deeper than 2 lateral clefts, or lateral clefts absent and calyx 2-lobed, or lateral clefts slightly deeper than abaxial and adaxial (C. plagiotoma); petals 5, corolla white to pale greenish proximally, usually becoming green, white, yellow, orange, red, pink, or purple distally, tubular proximally, strongly bilabiate distally and divided into adaxial beak of 2 lobes joined to tip, often with contrasting colors on margins, abaxial lip with 3 highly variable lobes, consisting of either greatly reduced, ± incurved, usually greenish teeth, or subpetaloid, contrastingly colored teeth, or shallow to deep, often more brightly colored pouches with small, apical, often contrastingly colored teeth, adaxial lip ± straight, beaked, opening directed forward; stamens 4, didynamous, filaments glabrous or spreading-hairy (C. exserta), pollen-sacs 2, unequal; staminode 0; ovary 2-locular, placentation axile; stigma capitate, entire, or 2-lobed. Capsules: dehiscence loculicidal. Seeds 20–100, mostly stramineous, ovoid, pyramidal, irregularly oblong-ovoid, or trapezoidal, shiny, wings absent. x = 12.
Distribution
North America, Mexico, Central America, South America, n Eurasia, in West Indies, Pacific Islands
Discussion
Species ca. 200 (119 in the flora).
Castilleja can be distinguished most easily from Orthocarpus in the strict sense by the structure of the flowers. The adaxial lip apices of Castilleja are more or less straight to slightly curved (hooked in C. chlorotica, C. exserta, C. mexicana, and C. sessiliflora) and never hooded, with the opening directed forward; in Orthocarpus the adaxial lip is rounded (straight in O. cuspidatus) and hooded, with the opening directed downward. In addition, Castilleja has a capitate to two-lobed stigma, while that of Orthocarpus is simple and unexpanded. An annual habit can be found in some Castilleja and all Orthocarpus. Castilleja has a base chromosome number of x = 12; Orthocarpus is x = 14. Presumed aneuploid reductions to x = 10 are known from three annual Castilleja species (two of these from Mexico), and a reduction to x = 11 is known from one species (T. I. Chuang and L. R. Heckard 1993).
Polyploidy is widespread in Castilleja, with about half of all species exhibiting at least one level of infra-specific polyploidy, including n = 24, 36, 48, 60, 72 (L. R. Heckard 1968; Heckard and T. I. Chuang 1977; Chuang and Heckard 1982).
Many species of Castilleja are fairly well defined morphologically and straightforward to identify using the keys; others have complex patterns of variation within local populations and across edaphic and geographic discontinuities. Some species groups, such as those surrounding C. affinis, C. miniata, and C. pallida, are especially challenging taxonomically, probably due at least in part to allopolyploidy (L. R. Heckard 1968; Heckard and T. I. Chuang 1977). Natural interspecific hybridization, though usually limited to individual plants or local populations, is well documented in the genus (N. H. Holmgren 1971; Heckard and Chuang). Hybrid swarms are observed in some regions, complicating identification (M. Ownbey 1959; J. M. Egger 1994), particularly among coastal populations from southeastern Alaska to central California. Homoploid hybrid speciation has also been proposed in at least one species in this genus (D. L. Clay et al. 2012).
Many of the characters used in the keys and descriptions are gathered from fresh plants. Floral characters were assessed at anthesis; one should avoid immature corollas as well as those persisting after flowering. Good collections require notes on variation in the fresh colors of bracts, calyces, and corollas. Pressing several examples of dissected flowers and bracts, separate from the plant, allows much easier measurement of corolla parts and calyx clefts, which are diagnostic for many taxa. Because these characters are difficult to assess once dried, herbarium material can be difficult to identify. Bract and flower coloration can be distinctive, but color variants are common in many taxa. Inflorescence color is usually a result of bright, non-green coloration in at least the distal portions of the bracts and calyces, although occasionally the corolla color contributes significantly to the coloration of the inflorescence or is more prominent than the colors of the other structures. The amount of bright distal coloration, especially on the bracts, is highly variable between species, within species, and even in individual plants. When only the color of the distal bracts or the distal portion of the bracts is reported here, the proximal bracts and/or the proximal part of the distal bracts are colored like the leaves. Also, in cases where bracts can be brightly colored either throughout or only distally in the same species, the colored throughout statement is presented first, followed by a statement such as "...or proximally greenish, distally as stated above." When the abaxial lip is described as reduced, it is a small green knob consisting of three incurved lobes and is not inflated. In relation to the leaf margins, two independently varying sub-traits are described. The authors contrast wavy (crisped) margins with plane (non-crisped) margins, and flat is used to contrast with involute or revolute margins.
In this treatment, the length of the corolla lobes and tube is measured from the point of contact in the notch between the abaxial lip and adaxial lip (beak). The junction of the lips is easier to find when the flower is fresh. Similarly, presence or absence of wavy leaf margins is easy to assess in the field and should be noted on herbarium labels, but this character is often obscured in herbarium material. While critical to species identification in only a few cases, woodiness or the subshrub habit and the presence of a woody caudex or rhizome should be noted in the field, as these characters are rarely evident in dried specimens.
Species of Castilleja occur in a wide range of habitats, from sea level to high alpine and from salt marshes and freshwater wetlands to tundra and deserts. Diversity is highest in grasslands, subalpine and alpine parklands, and other meadows, and is lower in densely forested regions. Some species tolerate a wide range of substrates, while others are specialists on soils derived from limestone, basalt, sandstone, granite, or serpentine.
All species of Castilleja are presumed to be root-hemiparasites, with most species studied experimentally growing more vigorously in the presence of a host (L. R. Heckard 1962). While some species of the Intermountain Region, such as C. chromosa, C. flava, and C. linariifolia, are closely associated with species of Artemisia (N. H. Holmgren 1984), host specificity is not well documented for many species. Some species occur primarily with Asteraceae hosts (especially Artemisia), Fabaceae (especially Lupinus), Poaceae (especially bunchgrasses), and Polygonaceae (especially Eriogonum) (M. Ownbey 1959; Holmgren; T. I. Chuang and Heckard 1993b; J. M. Egger, unpubl.). Many species of Castilleja will flower in greenhouse garden studies when grown on Helianthus and on mat-forming Raoulia Hooker f. ex Raoul species, both Asteraceae (Heckard; Egger, unpubl.).
Species with red to red-orange inflorescences often are visited and pollinated by nectar-seeking hummingbirds. These and other flower colors also attract nectar-gathering insects, mostly hymenopterans (especially Bombus) (J. M. Egger, unpubl.). Field observations confirm at least the occasional occurrence of selective, trap-line foraging on species of Castilleja by Hymenoptera. A few species, such as C. cryptantha, are self-pollinating (W. J. Duffield 1972). Some species are important food plants for various Lepidoptera larvae, especially Euphydryas (for example, P. R. Ehrlich et al. 1975) and Platyptilla (W. H. Lange 1950), and as nectar sources for hawkmoths (Hyles) (F. S. Crosswhite and C. D. Crosswhite 1970). Some species are known to serve as alternate or intermediate hosts for certain rust fungi (Cronartium, Endocronartium) (for example, D. B. O. Savile 1968c) and for hummingbird flower mites (Mesostigmata: Ascidae) (A. J. Heyneman et al. 1991). The leaves, stems, and inflorescences of many species are adult food sources for a variety of insects, including Coleoptera, Heteroptera, and Homoptera. Coleopteran species are especially common on a wide variety of species of Castilleja, especially in the inflorescences, and field studies show preliminary evidence of species-specific relationships between plant and beetle species. Species of Castilleja are grazed by Canada geese and by mammals, including voles, packrats, porcupines, deer, and introduced cattle, goats, and sheep.
Several species of Castilleja are used as ornamentals (J. Borland 1994; T. Luna 2005), as natural dyes, and by Native Americans for medicinal, practical, and ceremonial purposes (D. E. Moerman 1998).
A number of Castilleja species contain alkaloids, including some assimilated from parasitized hosts via haustorial bridges (for example, F. R. Stermitz and G. H. Harris 1987). Various Lepidopterans utilizing species of Castilleja as larval food plants either sequester or excrete the alkaloid chemicals (Stermitz et al. 1986, 1986b). The presence of alkaloids in the bracts and calyces of at least some species increases lifetime seed production through decreased herbivory and increased visitation by pollinators (L. S. Adler 2000). Some species of Castilleja are reported to absorb and concentrate selenium, producing potentially toxic effects in grazing animals (I. Rosenfeld and O. A. Beath 2013).
Many species of Castilleja decline when grazed by domestic livestock, especially on islands. Grazing by feral animals resulted in the extinction of one species (C. guadalupensis Brandegee) that occurred outside the flora area and the near extinction of several others, including the federally listed C. grisea and C. mollis. Plants are damaged both by cropping of inflorescences and by trampling of the often brittle stems. Removal of grazing pressures usually results in recovery of the affected populations. Numerous species in the flora area are of conservation concern, and many others are restricted in range and habitat and should be monitored. Most species in the flora area are endemic. A few species are peripheral in North America or extend into the mountains of northern and central Mexico or into the boreal and arctic regions of northeastern Asia.
Aside from limited taxonomic treatments in regional floras and works addressing particular species groups, the first comprehensive modern revision of the taxonomy and phylogenetic classification of Castilleja was the generic realignment and synopsis of the subtribe Castillejinae proposed by T. I. Chuang and L. R. Heckard (1991). In that work, Castilleja was considerably expanded, with the fragmentation of the traditional genus Orthocarpus and the movement of Orthocarpus sect. Castillejoides A. Gray into Castilleja, based on morphological congruities, base chromosome numbers, and other factors. Another monospecific genus, Gentrya Breedlove & Heckard, was also moved to Castilleja. Chuang and Heckard provided a detailed summary of earlier attempts at infrageneric classification in Castilleja and proposed the beginnings of a revised infrageneric classification, but their treatment in this regard was provisional and incomplete, primarily addressing the placement of the newly included groups and the species most closely related to them morphologically. More recently, additional comprehensive phylogenetic analyses of subtribe Castillejinae by D. C. Tank and R. G. Olmstead (2008) and Tank et al. (2009) largely confirmed the generic realignment by Chuang and Heckard but determined that two additional monospecific genera from Mexico, Ophiocephalus Wiggins and Clevelandia Greene, were well nested within a monophyletic Castilleja. However, no infrageneric classification for Castilleja was proposed at that time, due to discordance between previous taxonomic hypotheses and the results of genetic studies to date. Since the phylogenetic classification of Castilleja is the subject of ongoing research, no taxonomic structure for the North American species is proposed here.
Selected References
Lower Taxa
Keys
| 1 | Plants annual, sometimes biennial, with thin taproot or fibrous root system. | Group 1 |
| 1 | Plants perennial, sometimes biennial, with a ± woody caudex, sometimes from rhizomes. | > 2 |
| 2 | Woody shrubs or subshrubs; stem surfaces often nearly obscured by dense white (yellowish) hairs. | Group 2 |
| 2 | Herbs or subshrubs, or shrubs collected without diagnostic proximal parts; stem surfaces not obscured by dense white (yellowish) hairs (except C. arachnoidea, C. nivea, C. schizotricha, which are herbaceous). | > 3 |
| 3 | Calyces cleft into 4 subequal lobes. | Group 3 |
| 3 | Calyces cleft unequally in various ways, never divided into 4 subequal lobes. | > 4 |
| 4 | Stems with branched or stellate hairs, at least in part. | Group 4 |
| 4 | Stems glabrous or hairy but lacking branched or stellate hairs. | > 5 |
| 5 | Leaf margins conspicuously wavy (perpendicular to plane of blade; sometimes obscure in pressed material); stems with dense stipitate-glandular hairs, often mixed with eglandular hairs. | Group 5 |
| 5 | Leaf margins plane, sometimes ± wavy; stems stipitate-glandular or not. | > 6 |
| 6 | Corolla beaks relatively short, abaxial lip lengths 50–100% beak lengths. | Group 6 |
| 6 | Corolla beaks longer, abaxial lip lengths less than 50% beak lengths. | > 7 |
| 7 | Majority of leaves with 3–9 lobes, proximal leaves sometimes entireGroup 7, p. xxx. | Group 7 |
| 7 | Majority of leaves entire, sometimes distal leaves with 3–5(–7) lobes. | > 8 |
| 8 | Inflorescences yellow, yellow-green, yellow-orange, or white, sometimes tinged with pale red or purple. | Group 8 |
| 8 | Inflorescences usually reddish orange, bright red, pink-purple, or purplish red. | undefined |
| 1 | Abaxial and adaxial calyx clefts conspicuously deeper than lateral calyx clefts, lateral clefts absent or 1/20–1/4 depth of abaxial and adaxial clefts; bracts distally red to red-orange, yellow, green, or white, rarely pink, peach, or magenta. | > 2 |
| 2 | Bracts 0-lobed, apices acuminate or spatulate; mostly west of Continental Divide. | > 3 |
| 3 | Bracts plane-margined, narrowly lanceolate-acuminate, sometimes narrowly oblong or spatulate distally, apices red to orange, sometimes bright yellow; widespread in w North America. | Castilleja minor |
| 3 | Bracts wavy-margined, spatulate distally, apices white, sometimes very pale yellow, often aging dull pink to dull red-purple; Animas Valley, sw New Mexico. | Castilleja ornata |
| 2 | Bracts lobed or 0-lobed, apices not acuminate or spatulate; east of Continental Divide. | > 4 |
| 4 | Bracts greenish throughout; corollas conspicuously decurved distally; sw Texas. | Castilleja mexicana |
| 4 | Bracts greenish proximally, contrastingly colored distally; corollas ± straight, sometimes slightly curved; widespread east of Continental Divide, north to se Canada. | > 5 |
| 5 | Leaves and bracts deeply divided into (3–)5–9 lobes; widespread east of Continental Divide, north to sc Canada. | Castilleja coccinea |
| 5 | Leaves and bracts 0(–5)-lobed; se United States. | > 6 |
| 6 | Bracts distally pink to reddish, rarely white, peach, magenta, or yellow; basal rosettes of leaves usually absent; meadows, forest openings, various substrates including limestone; Arkansas, Louisiana, Oklahoma, and Texas, introduced sporadically along highways in Alabama and Florida. | Castilleja indivisa |
| 6 | Bracts distally bright yellow, rarely light orange; basal rosettes of leaves usually present; forest openings on dolomite limestone substrates; Bibb County, Alabama. | Castilleja kraliana |
| 1 | Abaxial and adaxial calyx clefts subequal to or only slightly deeper than lateral calyx clefts, lateral clefts well developed and at least 1/3 depth of abaxial and adaxial clefts; bracts green throughout or distally reddish purple, pink-purple, pink, dull reddish brown or brownish, cream, or white, rarely red, red-orange, or yellow. | > 7 |
| 7 | Distal bracts essentially unicolored, usually greenish to dull reddish brown, distal portions never strongly contrasting with proximal portions (except C. lasiorhyncha with distal margin sometimes white on immature bracts). | > 8 |
| 8 | Bracts and leaves 0-lobed. | Castilleja campestris |
| 8 | Bracts lobed; leaves lobed, sometimes 0-lobed. | > 9 |
| 9 | Corolla beaks obscured by dense, spreading hairs; distal margins of immature bracts white to rarely cream, with a tuft of white hairs; Cuyamaca, San Bernardino, San Jacinto, and Santa Rosa mountains, sw California. | Castilleja lasiorhyncha |
| 9 | Corolla beaks puberulent; distal margins of immature bracts green or brownish, rarely white (C. lacera), lacking tufted hairs; widespread w North America. | > 10 |
| 10 | Stigmas generally exserted, equal to or longer than corolla beak; abaxial corolla lips strongly inflated, 4–10 mm wide, 3–6 mm deep. | > 11 |
| 11 | Corollas 10–22 mm, abaxial lips 4–8 mm wide. | Castilleja lacera |
| 11 | Corollas (15–)20–28 mm, abaxial lips 8–10 mm wide. | Castilleja rubicundula |
| 10 | Stigmas included within corolla beaks; abaxial corolla lips moderately inflated, 2–4(–5) mm wide, 1–3 mm deep. | > 12 |
| 12 | Leaves linear to lanceolate, lobes linear; bract lobes linear or lanceolate, apices acute to acuminate; corollas white or yellow, usually with obscure, dull red to deep purple spots near bases of abaxial lips; widespread in w North America but not coastal and absent from Puget Trough region and Vancouver Island. | Castilleja tenuis |
| 12 | Leaves ovate to lanceolate, lobes linear to lanceolate; bract lobes lanceolate, apices broadly acute or obtuse; corollas distinctly bicolored, beaks white, sometimes faint purple, abaxial lips pale lemon yellow, unspotted; s Vancouver Island and islands bordering Haro Strait region of Puget Trough, British Columbia and Washington. | Castilleja victoriae |
| 7 | Distal bracts bicolored, usually greenish proximally, distal portions strongly contrasting with proximal portions. | > 13 |
| 13 | Corolla beaks prominently hooked and densely villous-hairy; filaments with long, soft, spreading hairs. | Castilleja exserta |
| 13 | Corolla beaks ± straight and inconspicuously puberulent; filaments glabrous. | > 14 |
| 14 | Inflorescences 1–2 cm wide; corolla tubes not expanded distally; abaxial lips inconspicuous, pouches 2 mm wide. | > 15 |
| 15 | Bracts 3(–5)-lobed, distally white to sometimes pale yellow or pale pink-purple; widespread in w coastal North America, including s California. | Castilleja attenuata |
| 15 | Bracts (3–)5-lobed, distally pink to purplish red; s Coast Ranges, s San Joaquin Valley and s Sierra Nevada foothills, California. | Castilleja brevistyla |
| 14 | Inflorescences 1–4 cm wide; corolla tubes expanded distally; abaxial lips conspicuous, pouches 3–7 mm wide. | > 16 |
| 16 | Abaxial lips of corollas yellow, bract lobes lanceolate to oblong; near the coast; British Columbia to California. | Castilleja ambigua |
| 16 | Abaxial lips of corollas not yellow or yellow distally (except C. ambigua), bract lobes linear or narrowly oblong; coastal and inland; California. | > 17 |
| 17 | Bracts green to purple proximally, purple to red-purple or white distally. | Castilleja densiflora |
| 17 | Bracts green to reddish brown proximally, sometimes with purple midrib, white to pale yellow or pale purple distally. | > 18 |
| 18 | Beaks (4–)5–7 mm; stems lacking stipitate-glandular hairs; coastal grasslands, San Luis Obispo County, California. | Castilleja densiflora |
| 18 | Beaks 1–5(–5.5) mm; stems with minute stipitate-glandular hairs; Sierra Nevada foothills and Napa County, California. | > 19 |
| 19 | Calyces 8–14 mm; beaks 1–4 mm; plants 0.6–2.2 dm; Napa County, California. | Castilleja ambigua |
| 19 | Calyces 15–25 mm; beaks (3–)4–5(–5.5) mm; plants 1.5–4.5 dm; Sierra Nevada foothills, California. | Castilleja lineariloba |
| 1 | Stems unbranched or sparsely branched on distal 1/2, hairs unbranched to strongly branched; s Channel Islands and California mainland to w Texas. | > 2 |
| 2 | Proximal stems or branches usually with dense leafy axillary shoots; stem hairs strongly branched; corollas 16–27 mm, beaks (7–)8.5–14 mm; California. | Castilleja foliolosa |
| 2 | Proximal stems or branches sometimes with dense leafy axillary shoots; stem hairs unbranched to moderately branched; corollas 23–35(–42) mm, beaks 11–22 mm; Arizona, New Mexico, sw Texas. | Castilleja lanata |
| 1 | Stems much-branched, including distal 1/2, hairs stellate or weakly branched; Channel Islands, California. | > 3 |
| 3 | Corolla beaks 7–9 mm; bracts and calyces distally pale yellow to green; bracts (3–)5–7-lobed; stem hairs stellate; San Clemente Island. | Castilleja grisea |
| 3 | Corolla beaks 11–14 mm; bracts and calyces distally yellow to red; bracts (0–)3-lobed; stem hairs weakly branched; n Channel Islands, absent on San Clemente Island. | Castilleja hololeuca |
| 1 | Stem hairs usually conspicuously matted and reflexed-spreading to ± appressed. | > 2 |
| 2 | Plants 1–4 dm; stems erect; montane to subalpine meadows; ne Arizona, s Colorado, nw New Mexico. | Castilleja lineata |
| 2 | Plants 0.5–2 dm, sometimes to 3 dm (C. arachnoidea); stems ascending to erect, sometimes proximally decumbent; alpine to subalpine meadows; n California, Montana, Nevada, s Oregon, nw Wyoming. | > 3 |
| 3 | Corolla beaks 6–8 mm; bracts greenish to pale yellow-green or very pale dull purplish; c, sw Montana, nw Wyoming. | Castilleja nivea |
| 3 | Corolla beaks (2–)3–5 mm; bracts pale yellow or soft greenish to dull red or soft purple, including intermediate shades; California, Nevada, Oregon. | > 4 |
| 4 | Hairs unbranched; plants 0.6–3 dm; leaves (1–)2–4(–6) cm; bracts dull yellow, dull or brick red, green, dull orange, or pink. | Castilleja arachnoidea |
| 4 | Hairs branched; plants 0.8–1.5 dm; leaves 0.5–2 cm; bracts various shades of soft purple. | Castilleja schizotricha |
| 1 | Stem hairs not conspicuously matted and spreading to reflexed (sometimes appearing more appressed if handled or pressed). | > 5 |
| 5 | Stems ashy gray; distal portions of bracts appearing dusty with dense, short stipitate-glandular hairs, many with a nodulose to pillarlike, crystallized, usually pigmented exudate, papillose at 40×; San Bernardino Mountains, s California. | Castilleja cinerea |
| 5 | Stems not ashy gray; distal portions of bracts not appearing dusty and, when stipitate-glandular hairs are present, lacking any crystallized exudate; n California, Idaho, Montana, Nevada, Oregon, Utah, Wyoming. | > 6 |
| 6 | Herbs (0.7–)1.2–3.5(–4.4) dm; stems ascending to erect, sometimes short-decumbent; bracts pale yellowish green, sometimes with pale purplish to brownish cast, especially with age; leaves 1–5.5(–8) cm; stems with eglandular hairs. | Castilleja pilosa |
| 6 | Herbs 0.4–1.5(–1.8) dm; stems decumbent at least proximally; bracts brownish green or whitish green to dull red or purple; leaves 0.5–3.2 cm; stems usually with glandular hairs. | > 7 |
| 7 | Corolla abaxial lips conspicuously exserted from calyces, teeth pink-purple to red-purple, erect and appressed to corolla beaks, beaks green; stigmas green; bracts mostly pink-purple to red-purple; alpine Wallowa Mountains, Oregon. | Castilleja rubida |
| 7 | Corolla abaxial lips slightly exserted or included within calyces, teeth white, cream, yellow, or pink, erect to slightly spreading; stigmas blackish; bracts brownish green or whitish green to dull greenish purple, red-purple, or pink-purple; e California, Nevada, Utah. | > 8 |
| 8 | Corollas 10–16(–19) mm, tubes 8–13 mm, beaks 3–5.5 mm, scarcely exceeding abaxial lips; leaves and bracts not fleshy; subalpine and alpine, not usually associated with hot springs; California, Nevada, Utah. | Castilleja nana |
| 8 | Corollas 18–22(–24) mm, tubes 13–18 mm, beaks 4.5–6.5 mm, noticeably exceeding abaxial lips; leaves and bracts often fleshy; mounded, alkaline hot spring outlets; ec Nevada. | Castilleja salsuginosa |
| 1 | Calyx abaxial clefts clearly shallower than laterals; bracts uniformly colored, green or yellowish green except for white hairs; sw California. | Castilleja plagiotoma |
| 1 | Calyx abaxial clefts clearly deeper than laterals; bracts distally colored differently from and more conspicuously than proximally, never uniformly green or yellowish green; widespread, including sw California. | > 2 |
| 2 | Stems not white-woolly to grayish, hairs sparse to ± dense. | > 3 |
| 3 | Leaves 0–5-lobed; short, leafy axillary shoots often conspicuous; calyx lobe apices acute to obtuse or rounded; coastal Santa Barbara and San Luis Obispo counties, California. | Castilleja affinis |
| 3 | Leaves 0-lobed, sometimes with 3–5 lobes distally; short, leafy axillary shoots usually lacking or inconspicuous; calyx lobe apices acute to acuminate; c, nw California to sw Oregon. | Castilleja pruinosa |
| 2 | Stems white-woolly to grayish, hairs dense. | > 4 |
| 4 | Leaves elliptic-oblong to obovate, 0-lobed; bracts 0–3-lobed, distally pale to bright yellow, sometimes brownish orange; Santa Rosa Island. | Castilleja mollis |
| 4 | Leaves linear to lanceolate, sometimes narrowly oblong or narrowly oblanceolate, distal leaves sometimes 0–5-lobed; bracts 0–7-lobed, distally red, orange, or yellow; Channel Islands and adjacent sw North America. | > 5 |
| 5 | Stems white-felted, with long, intertwined, sparsely branched hairs; leaves 0-lobed; n Channel Islands, California. | Castilleja hololeuca |
| 5 | Stems ashy gray or white-woolly with shorter, much-branched or stellate hairs; leaves 0–7-lobed; Oregon to Texas, including s Channel Islands of California. | > 6 |
| 6 | Distal portions of bracts pale yellow to green, hairs stellate; bracts (3–)5–7-lobed; San Clemente Island, California. | Castilleja grisea |
| 6 | Distal portions of bracts bright red to bright yellow (yellow-green), hairs much-branched; bracts 0–5-lobed; Santa Catalina Island and mainland of California, Arizona, New Mexico, w Texas. | > 7 |
| 7 | Lateral calyx clefts absent or inconspicuous. | > 8 |
| 8 | Proximal stems or branches usually with dense leafy axillary shoots, these overwintering; corollas 16–27 mm, beaks (7–)8.5–14 mm; California. | Castilleja foliolosa |
| 8 | Proximal stems or branches lacking dense leafy axillary shoots; corollas 23–35(–42) mm, beaks 11–22 mm; Arizona to Texas. | Castilleja lanata |
| 7 | Lateral calyx clefts 20–25% of calyx length. | > 9 |
| 9 | Calyx lobes ovate to narrowly triangular, apices obtuse to acute; abaxial corolla lips deep green to ± black; bracts (0–)3(–5)-lobed; stem hairs branched or often mixed with shorter, unbranched, stipitate-glandular ones; San Gabriel Mountains, sw California. | Castilleja gleasoni |
| 9 | Calyx lobes lanceolate to triangular, apices acute to acuminate; abaxial corolla lips deep green; bracts 0–5-lobed; stem hairs branched; c, nw California to sw Oregon. | Castilleja pruinosa |
| 1 | Corollas conspicuously decurved distally; bracts usually entirely green. | > 2 |
| 2 | Corolla beaks exserted, adaxial lips ± exserted, tubes included within calyx; c Oregon. | Castilleja chlorotica |
| 2 | Corollas (including majority of tubes) conspicuously exserted from calyx; sw Texas. | Castilleja mexicana |
| 1 | Corollas straight to slightly curved distally; bracts usually not entirely green, at least distally. | > 3 |
| 3 | Distal margins of central bract lobes, sometimes also side lobes, with multiple shallow teeth; plants coastal or near coastal. | Castilleja wightii |
| 3 | Distal margins of bract lobes entire, sometimes with a few shallow teeth; plants usually not coastal or near coastal (sometimes near coastal in C. martini var. martini). | > 4 |
| 4 | Bracts distally greenish to yellow-green or white, rarely red or pale pink. | > 5 |
| 5 | Bracts distally white to cream, sometimes shaded with pale, dull pink or pale yellow (sharply differentiated from proximal coloration), central lobe apices broadly rounded to truncate; 400–800 m. | Castilleja xanthotricha |
| 5 | Bracts distally greenish, yellow-green, cream, or yellow, rarely red to pale pink (sometimes gradually differentiated from proximal coloration), central lobe apices acute to acuminate or obtuse, rarely narrowly rounded; 1400–3200 m. | > 6 |
| 6 | Corollas (20–)22–30 mm, beaks 8–11(–12) mm; calyces 17–21(–23) mm; Blue and Strawberry mountains, Oregon. | Castilleja glandulifera |
| 6 | Corollas 16–22(–25) mm, beaks 5–8(–9) mm; calyces (10–)14–18 mm; mountains of e Oregon, Nevada, s Idaho. | Castilleja viscidula |
| 4 | Bracts distally red to red-orange (proximal bracts often entirely greenish in C. disticha), rarely yellowish to greenish or other color variants. | > 7 |
| 7 | Corollas 15–24(–26) mm, beaks 6–10 mm; plants 0.8–2.5(–5) dm. | > 8 |
| 8 | Lateral calyx clefts 3–5(–7) mm; calyx lobe apices acute, rarely obtuse; leaves 1.2–4.8 cm; usually granitic substrates; Sierra Nevada of California and Nevada. | Castilleja applegatei |
| 8 | Lateral calyx clefts 1.5–4 mm; calyx lobe apices obtuse to rounded; leaves 1–2(–2.5) cm; serpentine substrates; Siskiyou Mountains of nw California and sw Oregon. | Castilleja brevilobata |
| 7 | Corollas (20–)24–35(–45) mm, beaks 9–20 mm; plants 1–8 dm. | > 9 |
| 9 | Lateral calyx clefts (2–)3–8 mm, abaxials (4–)8–16(–19) mm; adaxial surfaces of corolla beaks usually greenish. | > 10 |
| 10 | Abaxial calyx clefts subequal to or slightly shallower than adaxials; sagebrush valleys to subalpine slopes; w United States. | Castilleja applegatei |
| 10 | Abaxial calyx clefts deeper than adaxials; upper montane to lower subalpine; mountains of c, ec Nevada. | Castilleja dissitiflora |
| 9 | Lateral calyx clefts 0.5–3(–5) mm, abaxials 3.4–8 mm; adaxial surfaces of corolla beaks usually reddish to yellowish green (or greenish in C. martini var. clokeyi). | > 11 |
| 11 | Bracts 0(–3)-lobed, all but distalmost entirely greenish. | Castilleja disticha |
| 11 | Bracts (0–)3–5(–7)-lobed, most contrastingly colored other than green distally. | > 12 |
| 12 | Corolla beaks equal to or longer than tubes; leaves green to sometimes purple; bract lobe apices obtuse to rounded. | Castilleja martini |
| 12 | Corolla beaks usually shorter than tubes; leaves gray-green, sometimes green; bract lobe apices acute, sometimes obtuse. | Castilleja montigena |
| 1 | Corollas conspicuously curved distally, at least distal portions of tubes conspicuously exserted from calyces. | > 2 |
| 2 | Lateral calyx clefts 1.5–6 mm; bracts greenish throughout; annuals or short-lived perennials; sw Texas. | Castilleja mexicana |
| 2 | Lateral calyx clefts 5–15 mm; bracts green to purplish throughout, sometimes reddish brown, pink, or lavender throughout, or distally white or pale yellow, sometimes distally dull pink, pink, salmon, orangish, pale pink-orange, buff, or cream; perennials; widespread in wc United States and sc Canada. | Castilleja sessiliflora |
| 1 | Corollas straight or slightly curved, tubes ± included within calyces. | > 3 |
| 3 | Leaves 0-lobed (except sometimes distally, just below inflorescences); boreal and arctic. | > 4 |
| 4 | Bracts yellow, yellow-green, or pale whitish throughout, sometimes with dull reddish-purplish wash proximally, especially with age. | Castilleja pallida |
| 4 | Bracts purple to lavender, pink-purple, or reddish purple throughout, sometimes proximally purple to pink-purple or reddish purple, distally whitish or pale pink. | > 5 |
| 5 | Plants 0.5–3 dm; stems unbranched. | Castilleja elegans |
| 5 | Plants (2.5–)3–5(–6) dm; stems unbranched to often branched distally. | Castilleja raupii |
| 3 | Leaves lobed, at least distally; w North America south of boreal-arctic region (except C. hyperborea). | > 6 |
| 6 | Lateral lobes of cauline leaves ± divaricate and often abruptly up-curved from plane of main leaf blade; nw Canada, Alaska. | Castilleja hyperborea |
| 6 | Lateral lobes of cauline leaves ascending to erect or ± spreading and gradually or not at all up-curved from plane of main leaf blade; extreme sw Canada, w United States. | > 7 |
| 7 | Calyx lobe apices acute (to rarely obtuse in C. thompsonii); xeric sites, usually with sagebrush. | > 8 |
| 8 | Corollas: abaxial lips scarcely expanded, glabrous or obscurely puberulent, 50–70% as long as corolla beak. | Castilleja thompsonii |
| 8 | Corollas: abaxial lips slightly but noticeably pouched, puberulent, 70–100% as long as corolla beak. | > 9 |
| 9 | Lateral calyx clefts 5–10 mm, lobes linear. | Castilleja oresbia |
| 9 | Lateral calyx clefts 0.5–4.3(–6) mm, lobes lanceolate to triangular. | Castilleja pallescens |
| 7 | Calyx lobe apices obtuse to rounded or acute, rarely truncate; ± mesic sites, not usually associated with sagebrush. | > 10 |
| 10 | Corollas 24–45(–50) mm, beaks and abaxial lips conspicuously exserted from calyces. | Castilleja kerryana |
| 10 | Corollas 12–25(–28) mm, beaks and abaxial lips included to scarcely and inconspicuously exserted from calyces, usually only stigmas and distal portions of beaks emergent. | > 11 |
| 11 | Central lobes of distal bracts rounded, sometimes truncate. | > 12 |
| 12 | Calyces 20–30 mm; plants (1–)1.5–5(–6) dm. | Castilleja cusickii |
| 12 | Calyces (12–)13–23(–25) mm; plants 0.5–1(–2) dm. | Castilleja pulchella |
| 11 | Central lobes of distal bracts acute to acuminate or obtuse, rarely narrowly rounded. | > 13 |
| 13 | Corollas 14–16 mm; vicinity of Mt. Rainier, Washington. | Castilleja cryptantha |
| 13 | Corollas 16–25 mm; California, Nevada, Oregon. | > 14 |
| 14 | Bracts pale cream to pale yellow, pale yellow-green, or greenish, often weakly infused with dull purple, sometimes other shades of above colors; Oregon. | > 15 |
| 15 | Bracts pale greenish or pale yellow-green throughout, or proximally greenish or pale yellow-green, distally yellow to whitish, sometimes pink-purple, or pale, dull purplish, sometimes aging pink or yellow, often infused with light purple, rarely pink; Blue and Wallowa mountains, ne Oregon. | Castilleja chrysantha |
| 15 | Bracts pale cream to pale greenish yellow throughout, often partly to entirely suffused with dull reddish purple to maroon, especially proximally, along veins, and with age, sometimes distal apices pale dullish red; Cascade Range, Klamath County, s Oregon. | Castilleja collegiorum |
| 14 | Bracts green to brownish or purplish proximally, pink to purple or magenta distally, rarely white; California, closely adjacent Nevada. | > 16 |
| 16 | Corolla beaks adaxially white or white with pale salmon margins; abaxial lips pale green to yellow-green, with white distal teeth; stigmas pale green; Mt. Lassen region, Cascade Range, California. | Castilleja lassenensis |
| 16 | Corolla beaks adaxially green with red margins; abaxial lips greenish with pink-purple distal teeth; stigmas greenish to deep bluish purple; Sierra Nevada, California and adjacent Nevada. | Castilleja lemmonii |
| 1 | Corolla beaks clearly 1/2+ as long as corollas. | > 2 |
| 2 | Corolla beaks 22–39 mm; abaxial calyx clefts much (11+ mm) deeper than adaxials; se Arizona, sw New Mexico. | Castilleja patriotica |
| 2 | Corolla beaks 8–24 mm; abaxial calyx clefts subequal to or slightly (less than 2 mm) shallower than adaxials; Pacific Northwest and California to Idaho and Utah. | > 3 |
| 3 | Shrubs or subshrubs; stems white-woolly; n Channel Islands, California. | Castilleja hololeuca |
| 3 | Herbs; stems not white-woolly; mainland of w North America. | > 4 |
| 4 | Bracts lanceolate to oblong; corolla beaks 8–15 mm; se Idaho, ne Nevada, w Utah. | Castilleja angustifolia |
| 4 | Bracts obovate to ovate or orbicular; corolla beaks 14–24 mm; Cascade Range and west, s British Columbia to Oregon. | > 5 |
| 5 | Stems mostly glabrous; bracts mostly obovate to orbicular, lobes mostly arising at or above mid length, short and medium length, lanceolate to triangular, apices acute; Coast Range, Clatsop County, Oregon, and Pacific County, Washington. | Castilleja chambersii |
| 5 | Stems with short, soft, spreading hairs; bracts ovate to orbicular, lobes arising below mid length, long, linear to linear-lanceolate, apices rounded to acute; Cascade Range and Columbia River Gorge, s British Columbia to Oregon. | Castilleja rupicola |
| 1 | Corolla beaks ca. 1/2 or less than 1/2 as long as corollas. | > 6 |
| 6 | Abaxial corolla lips usually not pouched, teeth prominent, petaloid, spreading to erect, not completely greenish nor incurved. | > 7 |
| 7 | Bracts and calyces distally yellow, sometimes orange-yellow. | Castilleja citrina |
| 7 | Bracts and calyces distally various shades of red, red-orange, orange, purple, or pink, rarely yellowish or white. | > 8 |
| 8 | Bracts and calyces distally red to reddish orange or pale orange. | Castilleja lindheimeri |
| 8 | Bracts and calyces distally purple to pink-purple or pink, light orange, or light yellow, rarely white. | Castilleja purpurea |
| 6 | Abaxial corolla lips either ± pouched and with small, erect teeth or apiculations, or teeth reduced, not petaloid, not spreading, entirely greenish and incurved. | > 9 |
| 9 | Bracts green or yellow-green throughout, or proximally green to yellow-green, distally yellow to sometimes pale yellow-orange, hairs white; corolla tubes 5–14 mm. | > 10 |
| 10 | Calyces divided more deeply abaxially than laterally; ne Arizona, s Colorado, nw New Mexico. | Castilleja lineata |
| 10 | Calyces only slightly divided abaxially, more deeply divided laterally; sw California. | Castilleja plagiotoma |
| 9 | Bracts at least distally red, rose, purple, yellow, or orange, rarely green, white, or cream; corolla tubes 8–24 mm. | > 11 |
| 11 | Stems glabrate, sometimes puberulent proximally. | > 12 |
| 12 | Bracts distally red to red-orange, very rarely yellowish. | > 13 |
| 13 | Stems few to several, clustered, from a woody caudex; bracts lacking a yellowish medial band; Rocky Mountains, Montana and Wyoming. | Castilleja crista-galli |
| 13 | Stems usually solitary from slender, creeping rhizomes; bracts usually with a narrow, distinct yellow medial band; Cascade Range, Oregon and s Washington. | Castilleja suksdorfii |
| 12 | Bracts distally pink-purple to red-purple, lilac purple, rose red, pink, or white, rare individuals red to orange-red in populations of purple plants. | > 14 |
| 14 | Stems glabrate or puberulent, 0.7–2 dm; corollas 20–25 mm; alpine; s Rocky Mountains, sc Colorado, n New Mexico, se Utah. | Castilleja haydenii |
| 14 | Stems glabrate proximally, hairy distally, (0.6–)1–4(–5) dm; corollas 12–30 mm; subalpine to lower alpine; widespread in mountains of nw North America. | Castilleja parviflora |
| 11 | Stems hairy. | > 15 |
| 15 | Adaxial calyx clefts deeper than abaxials. | > 16 |
| 16 | Corolla beaks 50–70% as long as tubes; not associated with sagebrush; Rocky Mountains, c Idaho and adjacent Montana. | Castilleja covilleana |
| 16 | Corolla beaks 85–100% as long as tubes; usually associated with sagebrush; widespread in w United States. | > 17 |
| 17 | Bracts distally pink, magenta, pink-purple, reddish pink, pale yellow, pale yellow-orange, pale orange, or white, rarely reddish or orange-red; calyces 13–25(–28) mm; corolla beaks 8–15 mm; s Idaho, sw Montana, e Nevada, se Oregon, sw South Dakota, w Utah, n Wyoming. | Castilleja angustifolia |
| 17 | Bracts distally bright red to scarlet or orange-red, rarely yellowish to dull orange or pink; calyces (17–)20–27 mm; corolla beaks (9–)10–18 mm; Arizona, e California, w Colorado, e Oregon, s Idaho, Nevada, nw New Mexico, Utah, s, w Wyoming. | Castilleja chromosa |
| 15 | Abaxial and adaxial calyx clefts subequal, adaxials only slightly deeper, or abaxials deeper than adaxials. | > 18 |
| 18 | Corolla beaks 7–22 mm. | > 19 |
| 19 | Corollas 18–24 mm; bracts (0–)3–5-lobed; stems with mixture of long, soft, spreading, eglandular hairs and shorter stipitate-glandular hairs; leaf margins ± wavy, sometimes plane; substrates serpentine; Siskiyou Mountains, nw California, sw Oregon. | Castilleja brevilobata |
| 19 | Corollas 17–40(–45) mm; bracts 0–7(–11)-lobed; stems with short to long, stiff to soft, spreading hairs, sometimes mixed with stipitate-glandular hairs; leaf margins usually plane, often mixed with wavy-margined leaves (C. affinis, C. hispida); substrates serpentine or not; widespread in w North America. | > 20 |
| 20 | Stems with dense, whitish, short hairs; plants decumbent, often sprawling, distally ascending, 0.7–1.5(–2.2) dm; inflorescences 2.5–10 cm; leaves gray-green, sometimes green or reddish purple; Nevada to New Mexico. | Castilleja scabrida |
| 20 | Stems with long, soft to stiff hairs and short-glandular or eglandular hairs; plants erect or ascending, 1.3–6 dm; inflorescences 3–30 cm; leaves green, purplish, or red-brown; Alberta and British Columbia to Arizona. | > 21 |
| 21 | Stems unbranched or often branched at proximal nodes; short, leafy axillary shoots common, usually conspicuous; lateral lobes of leaves almost as wide as mid blade; w California. | Castilleja affinis |
| 21 | Stems unbranched; short, leafy axillary shoots absent or, when present, inconspicuous; lateral lobes of leaves much narrower than mid blade; nw United States, sw Canada. | Castilleja hispida |
| 18 | Corolla beaks 4–8(–12) mm. | > 22 |
| 22 | Central bract lobes acute to acuminate, sometimes narrowly obtuse (C. flava). | > 23 |
| 23 | Inflorescences a variable and often contrasting mixture of bright yellow and bright red; Sierra Nevada, California and adjacent Nevada. | Castilleja peirsonii |
| 23 | Inflorescences soft yellow to pale yellow-green, sometimes tinged with dull reddish or orange; Great Basin and Rocky Mountains. | > 24 |
| 24 | Herbs 1.5–5.5(–7.5) dm; sagebrush or montane; Oregon to Montana. | Castilleja flava |
| 24 | Herbs 0.8–1.5 dm; alpine to subalpine; c Rocky Mountains, Colorado, disjunct in se Montana. | Castilleja puberula |
| 22 | Central bract lobes rounded to obtuse, sometimes truncate. | > 25 |
| 25 | Bracts usually distally bright red to red-orange. | > 26 |
| 26 | Leaf margins plane; inflorescences 2.5–7.5(–15) cm; bract lobes arising above mid length except on proximal bracts; 1700–3400 m; Sierra Nevada, California and adjacent Nevada. | Castilleja peirsonii |
| 26 | Leaf margins plane or wavy; inflorescences 3–25(–30) cm; bract lobes arising above or below mid length; 0–1200(–1700) m; w of Sierra Nevada, California and adjacent sw Oregon. | > 27 |
| 27 | Stem hairs usually eglandular; corolla beaks subequal to or longer than tube; corollas 17–40 mm; abaxial and adaxial calyx clefts 6–22 mm; substrates serpentine or not; w California. | Castilleja affinis |
| 27 | Stem hairs stipitate-glandular; corolla beaks subequal to or shorter than tube; corollas 15–24(–26) mm; abaxial and adaxial calyx clefts 5.5–8.5 mm; substrates serpentine; nw California, sw Oregon. | Castilleja brevilobata |
| 25 | Bracts distally yellow, whitish, purplish, dull red, pinkish, or dull orange. | > 28 |
| 28 | Abaxial corolla lip teeth reduced to minute apiculations; s Sierra Nevada, California. | Castilleja praeterita |
| 28 | Abaxial corolla lip teeth not reduced to minute apiculations; s British Columbia, California, Oregon, Washington. | > 29 |
| 29 | Inflorescences bright yellow or light yellow, usually becoming deep golden yellow; bracts (0–)5–9(–13)-lobed, lobes arising above mid length; Puget Trough, British Columbia and Washington, and Willamette Valley, Oregon. | Castilleja levisecta |
| 29 | Inflorescences red, orange, yellow, or white, never becoming deep golden yellow; bracts (0–)3–7-lobed, proximal lobes arising below mid length (except in C. brevilobata); California, Oregon, absent in Puget Trough and Willamette Valley. | > 30 |
| 30 | Corolla beaks puberulent, eglandular; stem hairs usually eglandular; leaves 2–13 cm; w California. | Castilleja affinis |
| 30 | Corolla beaks puberulent, stipitate-glandular; stem hairs mostly stipitate-glandular; leaves 0.8–6 cm; California, Oregon. | > 31 |
| 31 | Bracts distally red, red-orange, or scarlet, sometimes orange or yellow; corollas 15–24(–26) mm, beaks ca. 50% as long as corollas; plants 1–5 dm; substrates of serpentine origin; nw California, sw Oregon. | Castilleja brevilobata |
| 31 | Bracts distally white to cream, rarely pale yellow or dull, pale pink; corollas 17–23 mm, beaks ca. 33% as long as corollas; plants 1–2(–3.8) dm; substrates of basaltic origin; nc Oregon. | Castilleja xanthotricha |
| 1 | Corolla tubes 24–45 mm, usually partly exserted; corollas strongly curved distally. | Castilleja sessiliflora |
| 1 | Corolla tubes usually less than 25 mm, mostly included within calyces; corollas straight or slightly curved. | > 2 |
| 2 | Stems solitary, sometimes few, proximally creeping and becoming rhizomatous, attached to a remote caudex; wet meadows or bogs, sometimes near hot springs. | > 3 |
| 3 | Calyces 9–17 mm; corolla tubes 7–12 mm; serpentine bogs and wetlands; nw California, sw Oregon. | Castilleja elata |
| 3 | Calyces 15–22 mm; corolla tubes 11–19 mm; non-serpentine wet meadows, sometimes near hot springs; Idaho, Montana, Oregon, Wyoming. | Castilleja gracillima |
| 2 | Stems few to many, rarely solitary, rhizomatous or not; wet or dry meadows. | > 4 |
| 4 | Stems loosely lanate. | Castilleja genevieveana |
| 4 | Stems glabrous or variously hairy, never lanate. | > 5 |
| 5 | Leaves densely crowded; stems usually much-branched, usually with short, leafy axillary shoots; 0–700 m; coastal; c, n California. | Castilleja wightii |
| 5 | Leaves not densely crowded; stems branched or unbranched, lacking short, leafy axillary shoots; 0–4300 m; inland (except for C. miniata var. dixonii, C. unalaschcensis); w North America. | > 6 |
| 6 | Stems usually unbranched; plants 1–3(–4) dm. | > 7 |
| 7 | Stem hairs including stipitate-glandular ones both in inflorescence and proximal to it. | > 8 |
| 8 | Bracts 3–5-lobed, lateral lobes medium to long; quartzite substrates; near summit of Mt. Harrison, Albion Mountains, Idaho. | Castilleja christii |
| 8 | Bracts 0(–5)-lobed, rarely with 1 or 2 pairs of short, usually distal lobes; serpentine substrates, sometimes not; Cascade Mountains, s British Columbia and Washington. | Castilleja elmeri |
| 7 | Stem hairs eglandular below inflorescence, only stipitate-glandular in inflorescence. | > 9 |
| 9 | Stems several to many, usually short-decumbent near base, becoming ascending-erect distally; bracts often conspicuously dull reddish brown or reddish purple proximally, especially with age; upper subalpine to alpine; Rocky Mountains. | Castilleja occidentalis |
| 9 | Stems solitary to few, erect to ascending; bracts not conspicuously dull reddish brown or reddish purple proximally; usually montane to subalpine; nw Arizona, sc Utah. | > 10 |
| 10 | Corollas 17–25 mm; stems ascending, sometimes erect; inflorescences pale yellow, rarely yellow-orange; Aquarius Plateau, sc Utah. | Castilleja aquariensis |
| 10 | Corollas 21–30(–35) mm; stems erect, sometimes ascending; inflorescences whitish to pale yellow, pale yellow-orange, pale reddish orange, or salmon; Kaibab Plateau, nw Arizona. | Castilleja kaibabensis |
| 6 | Stems branched or unbranched; plants (1.4–)2.5–6(–8) dm. | > 11 |
| 11 | Calyx lobe apices acute to rounded or obtuse; lateral lobe apices of bracts, when present, acute to obtuse or narrowly rounded. | > 12 |
| 12 | Bracts usually divided, with 1–3 pairs of medium-length lateral lobes. | > 13 |
| 13 | Stems with short, scabrid hairs below inflorescence; calyces 15–25 mm; corollas 21–27 mm; nw United States, adjacent sw Canada. | Castilleja lutescens |
| 13 | Stems with long, soft, spreading hairs; calyces 13–20 mm; corollas (15–)17–27 mm; White Mountains, ec Arizona. | Castilleja mogollonica |
| 12 | Bracts entire or shallowly divided, with 1 or 2 pairs of short lateral lobes. | > 14 |
| 14 | Lateral calyx clefts 1–4 mm; bracts distally usually whitish to pale yellow (pale pink), 0–3(–5)-lobed; montane and subalpine meadows and slopes; Rocky Mountains and eastward. | Castilleja septentrionalis |
| 14 | Lateral calyx clefts 4–10 mm; bracts distally usually yellow to yellow-orange (whitish), (0–)3–5-lobed; open coastal habitats, lower montane to lower alpine meadows in mountainous regions; British Columbia, Yukon, Alaska. | Castilleja unalaschcensis |
| 11 | Calyx lobe apices usually acute to acuminate; lateral lobe apices of bracts, when present, usually acute to acuminate. | > 15 |
| 15 | Abaxial calyx clefts deeper than adaxials. | > 16 |
| 16 | Herbs (2.3–)3–8 dm; leaves usually greenish, unaffected by pubescence; grasslands, balds, and open pine forests; s British Columbia, n Idaho, nc, ne Washington. | Castilleja cervina |
| 16 | Herbs 1.5–4(–5.5) dm; leaves often grayish from pubescence; primarily sagebrush slopes and flats; Colorado, s, c Idaho, w Montana, Nevada, Utah, Wyoming. | Castilleja flava |
| 15 | Abaxial calyx clefts subequal to adaxials. | > 17 |
| 17 | Bracts pale yellow to cream, sometimes greenish proximally; Sonoma County, California. | Castilleja uliginosa |
| 17 | Bracts at least distally wide range of colors, rarely yellow or yellow-orange (except for C. miniata var. fulva); widespread in w North America, not in Sonoma County, California. | > 18 |
| 18 | Bracts at least distally pink, magenta, or purple, sometimes buff, dull yellow, cream, or light yellow-orange; serpentine bogs and wetlands; Siskiyou Mountains, nw California and sw Oregon. | Castilleja elata |
| 18 | Bracts at least distally yellow to tawny yellow, pale yellow-orange, or pale reddish; non-serpentine substrates; n British Columbia and adjacent Alberta and Yukon. | Castilleja miniata |
| 1 | Corolla tubes 24–45 mm, distal portion often exserted from calyces; corollas strongly curved distally. | Castilleja sessiliflora |
| 1 | Corolla tubes usually 30 mm or less, mostly included within calyces; corollas straight or slightly curved. | > 2 |
| 2 | Stems woolly to lanate, hairs usually obscuring surfaces. | > 3 |
| 3 | Bracts usually entire, apices rounded distally, sometimes with 1 or 2 pairs of short, lateral lobes usually arising at or above mid length. | Castilleja integra |
| 3 | Bracts usually deeply divided, apices acute to rounded distally, a pair of much longer lateral lobes often originating from well below mid length. | > 4 |
| 4 | Calyx lobes truncate, rounded, emarginate, or divided 0–5 mm into obtuse or rounded lateral lobes; stems densely lanate to woolly, hairs branched or unbranched; s Arizona, s New Mexico, sw Texas. | Castilleja lanata |
| 4 | Calyx lobes divided 5–7 mm into linear to lanceolate lateral lobes, apices ± acute; stems moderately lanate, hairs unbranched; Animas Valley and south, sw New Mexico. | Castilleja tomentosa |
| 2 | Stems glabrous or hairy, not woolly or lanate, hairs, if any, not obscuring surfaces. | > 5 |
| 5 | Lateral calyx clefts 0–0.5 mm. | > 6 |
| 6 | Abaxial calyx clefts conspicuously deeper than adaxials; bract apices acute. | Castilleja tenuiflora |
| 6 | Calyx clefts usually subequal; bract apices rounded to obtuse or truncate. | > 7 |
| 7 | Calyces distally deep green, deep purple, or blackish; stems ± straight; corolla beaks usually included in calyces; se Arizona. | Castilleja nervata |
| 7 | Calyces distally bright red; stems subtly wavy, curving back and forth slightly throughout their length; corolla beaks exserted from calyces; sw Texas. | Castilleja rigida |
| 5 | Lateral calyx clefts usually 1–12 mm (sometimes less than 1 mm in C. subinclusa and C. leschkeana of California). | > 8 |
| 8 | Bracts at least distally pink, pink-purple, red-purple, or deep purple, rarely whitish. | > 9 |
| 9 | Plants 0.8–1.5(–2) dm; stems usually unbranched; sc or sw Utah. | > 10 |
| 10 | Calyces 12–18 mm, abaxial and adaxial clefts 5.5–8.5(–10) mm; stems several to many; alpine; Tushar Mountains, sc Utah. | Castilleja parvula |
| 10 | Calyces 16.5–27 mm, abaxial and adaxial clefts (8–)10–15(–18) mm; stems solitary, sometimes few; pine forests; Aquarius, Markagunt, and Paunsaugunt plateaus, Utah. | Castilleja revealii |
| 9 | Plants (1–)2–7(–8) dm; stems branched or unbranched; w United States, sw Canada, not sc or sw Utah (except C. rhexiifolia). | > 11 |
| 11 | Corolla beaks 12–20 mm. | Castilleja affinis |
| 11 | Corolla beaks 6–16 mm. | > 12 |
| 12 | Stems branched or unbranched; calyx lobe apices acute to acuminate; leaf apices acute to acuminate; se Alberta and se British Columbia or Siskiyou Mountains. | > 13 |
| 13 | Bracts at least distally pink, magenta, or purple, sometimes distally buff, dull yellow, cream, or light yellow-orange; serpentine bogs and wetlands, sometimes gravelly river bars; Siskiyou Mountains, nw California and sw Oregon. | Castilleja elata |
| 13 | Bracts at least distally deep reddish or crimson, rarely magenta or dull orange; gravel river flats, moist thickets; sw Alberta, se British Columbia. | Castilleja purpurascens |
| 12 | Stems usually unbranched; calyx lobe apices obtuse to rounded, sometimes ± acute (C. rhexiifolia); leaf apices acute; Rocky Mountains, s British Columbia, Oregon, Washington. | > 14 |
| 14 | Stems pubescent, hairs moderately dense and of medium length, mixed with shorter eglandular and stipitate-glandular ones; bracts 0(–5)-lobed; 600–2600 m; Wenatchee Mountains, Washington, northward in Cascade Mountains to s British Columbia. | Castilleja elmeri |
| 14 | Stems proximally glabrous to glabrate, distally sparsely pubescent, hairs ± long, soft, eglandular, sometimes stipitate-glandular; bracts (0–)3–5(–7)-lobed; 1800–4000 m; widespread in Rocky Mountains, disjunct in ne Oregon, ne Washington. | Castilleja rhexiifolia |
| 8 | Bracts at least distally red to red-orange, sometimes some populations with a few plants with yellow, white, or pink inflorescences. | > 15 |
| 15 | Leaves cupulate, sometimes obscurely so on distal portion of stem, sometimes ± fleshy, apices truncate or obtuse to broadly rounded; coastal; c, n California to Curry County, Oregon. | > 16 |
| 16 | Corollas 19–30 mm, beaks 8.5–15 mm; c California. | Castilleja latifolia |
| 16 | Corollas 28–45 mm, beaks 15–25 mm; nw California to Curry County, Oregon. | Castilleja mendocinensis |
| 15 | Leaves not cupulate, sometimes thickened but not fleshy, apices acute to acuminate or obtuse, rarely rounded (except in C. litoralis, C. wightii); coastal to inland; w North America. | > 17 |
| 17 | Plants 0.8–2.5 dm; calyces brightly and conspicuously colored for at least distally 2/3 and often throughout, providing much of inflorescence color, clefts subequal; alpine to subalpine; Wallowa Mountains, ne Oregon. | Castilleja fraterna |
| 17 | Plants 1–10(–20) dm, usually 2+ dm; calyces often less colorful, usually providing a less significant portion of inflorescence color, except when abaxial clefts deeper than adaxials, clefts subequal or abaxials deeper or adaxials ± deeper; sea level to subalpine; w North America, including Wallowa Mountains, Oregon. | > 18 |
| 18 | Abaxial calyx clefts deeper than adaxials. | > 19 |
| 19 | Stem hairs at least partially stipitate-glandular; California. | Castilleja subinclusa |
| 19 | Stem hairs not stipitate-glandular; Arizona to Texas. | > 20 |
| 20 | Lateral calyx clefts 0(–2.5) mm; bracts 0-lobed, rarely with 1 pair of lateral lobes arising near apex; stems densely short-pubescent. | Castilleja tenuiflora |
| 20 | Lateral calyx clefts 1.5–7 mm; bracts usually with 1–3 pairs of lateral lobes arising above or below mid length; stems glabrous to sometimes ± pubescent. | > 21 |
| 21 | Abaxial calyx clefts 3–5 times deeper than adaxials; bracts usually 3-lobed; widespread in w North America (parapatric with C. wootonii in New Mexico). | Castilleja linariifolia |
| 21 | Abaxial calyx clefts 1.2–2 times deeper than adaxials; bracts usually 3–5-lobed; New Mexico, w Texas. | Castilleja wootonii |
| 18 | Abaxial calyx clefts subequal to or shallower than adaxials. | > 22 |
| 22 | Lateral calyx clefts 7–11 mm; se Alaska. | Castilleja chrymactis |
| 22 | Lateral calyx clefts 1–8 mm; widespread including se Alaska. | > 23 |
| 23 | Abaxial calyx clefts shallower than adaxials; mountains of c, e Nevada. | Castilleja dissitiflora |
| 23 | Calyx clefts subequal; w North America. | > 24 |
| 24 | Calyx lobe apices rounded to obtuse, rarely acute. | > 25 |
| 25 | Pedicels 0 mm or nearly so; range not limited to immediate coast. | > 26 |
| 26 | Stem hairs usually not stipitate-glandular; abaxial and adaxial calyx clefts 6–22 mm; California w of Sierra Nevada. | Castilleja affinis |
| 26 | Stem hairs usually stipitate-glandular; abaxial and adaxial calyx clefts 5–14 mm; near coast of c, n California or Cascade Range from s British Columbia to c Washington. | > 27 |
| 27 | Bracts 0(–5)-lobed; corolla tubes 13–18 mm, beaks 8–15 mm; montane to subalpine; Wenatchee Mountains and Cascade Range, c, n Washington and s British Columbia. | Castilleja elmeri |
| 27 | Bracts (0–)3–5(–7+)-lobed; corolla tubes 10–12 mm, beaks 11.5–18 mm; coastal and near-coastal bluffs, slopes, and canyons; n, c California. | Castilleja wightii |
| 25 | Pedicels 0–6 mm; range at immediate coast. | > 28 |
| 28 | Stems usually much-branched, usually with prominent leafy axillary shoots, pubescent, with hairs including stipitate-glandular ones; corollas 20–30 mm; c, n California. | Castilleja wightii |
| 28 | Stems often branched, usually lacking prominent leafy axillary shoots, usually glabrous or glabrate, often puberulent distally, hairs, when present, usually not stipitate-glandular; corollas 25–46 mm; nw California to sw British Columbia, including coastal Puget Sound. | > 29 |
| 29 | Corollas 23–38(–40) mm, beaks 10–16 mm, adaxial surfaces inconspicuously puberulent; lateral calyx clefts 1–3(–5) mm, 5–12% of calyx length; far nw California to Pacific County, Washington. | Castilleja litoralis |
| 29 | Corollas 25–46 mm, beaks 11–25 mm, adaxial surfaces ± conspicuously puberulent; lateral calyx clefts 2–7 mm, 15–30% of calyx length; Clatsop County, Oregon, northward to s British Columbia. | Castilleja miniata |
| 24 | Calyx lobe apices acute to acuminate, rarely obtuse. | > 30 |
| 30 | Bract veins usually yellow, conspicuously contrasting with base color; calyces mostly yellow, with scarlet to red or red-orange apices, these matching distal coloration of bracts; stems without stipitate-glandular hairs; sky island mountain ranges, c, e Arizona, w New Mexico. | Castilleja nelsonii |
| 30 | Bract veins not yellow, not conspicuously contrasting with base color; calyces not mostly yellow, not with scarlet to red or red-orange apices; stems with or without stipitate-glandular hairs; widespread, including Arizona, New Mexico. | > 31 |
| 31 | Plants 1.3–5 dm; stems usually unbranched; leaves usually 0-lobed proximally, 3-lobed distally. | Castilleja hispida |
| 31 | Plants 1.2–10 dm; stems usually branched; leaves usually 0-lobed, rarely 3–5-lobed distally. | > 32 |
| 32 | Bracts cuneate to obovate-truncate; vicinity of Pt. Reyes Peninsula, California. | Castilleja leschkeana |
| 32 | Bracts lanceolate to ovate, obovate, oblong-ovate, or oblong; widespread in w North America. | > 33 |
| 33 | Inflorescences 2–4.5 cm, bracts 0(–3)-lobed; Organ Mountains of s New Mexico. | Castilleja organorum |
| 33 | Inflorescences 2.5–21 cm, bracts 0–5(–7)-lobed; widespread in w North America. | > 34 |
| 34 | Corolla beaks usually 14–25 mm; inflorescences usually bearing a thin coat of whitish, powdery exudate. | Castilleja miniata |
| 34 | Corolla beaks 8–16 mm; inflorescences lacking a whitish exudate. | > 35 |
| 35 | Bracts usually 3–5-lobed; coastal, 0–200 m; far nw California to far sw Washington. | Castilleja litoralis |
| 35 | Bracts usually 3-lobed; not coastal, 1400–2600 m; c, e Oregon and adjacent Idaho and Nevada. | Castilleja peckiana |