Marshallia
Gen. Pl. 2: 810. 1791.
| Taxon | Illustrator ⠉ | |
|---|---|---|
 | Tetraneuris acaulis Psilostrophe tagetina Marshallia caespitosa Marshallia graminifolia | Yevonn Wilson-Ramsey Yevonn Wilson-Ramsey Yevonn Wilson-Ramsey Yevonn Wilson-Ramsey |
Perennials, (10–) 20–80 (–120) cm (fibrous-rooted, usually with caudices, sometimes rhizomatous). Stems erect, sometimes branched (striate). Leaves basal and/or cauline; alternate; petiolate or sessile; blades (1-nerved or 3-nerved) elliptic, linear, linear-elliptic, linear-oblanceolate, oblanceolate, ovate, or spatulate, margins entire, faces glabrous. Heads discoid, borne singly or in open, corymbiform arrays (peduncles relatively long). Involucres hemispheric to obconic, 10–25+ mm diam. Phyllaries persistent, 12–24 in ± 2 series (lanceolate, linear, oblong, ovate, or rhombic, subequal, herbaceous, midnerves often keeled, proximal margins often scarious). Receptacles conic or convex (usually hollow), paleate (paleae linear to spatulate, distally herbaceous). Ray-florets 0. Disc-florets (20–) 45–90 (–160+), bisexual, fertile; corollas pale lavender, pink, or purple, or white, (usually hairy) tubes longer than to nearly equaling throats, lobes 5, lance-linear to linear-oblong (often contorted). Cypselae turbinate or clavate (5-angled, ribs 10, often hairy); pappi persistent, of 5 (–6) scarious to membranous (hyaline, sometimes scaberulous) scales. x = 9.
Distribution
s, c, se United States
Discussion
Species 7 (7 in the flora).
Selected References
Lower Taxa
Key
| 1 | Leaves lance-elliptic, lance-linear, linear, or oblanceolate (lengths mostly 13–30 times widths), widths mostly 2–13 mm | > 2 |
| 1 | Leaves elliptic, lanceolate, oblanceolate, ovate, or spatulate (lengths mostly 3–13 widths), widths 8–33 mm | > 4 |
| 2 | Corollas usually pale lavender to purple, rarely white; flowering Aug–Sep | Marshallia graminifolia |
| 2 | Corollas usually white, sometimes pale lavender; flowering May–Jun | > 3 |
| 3 | Heads 4–10, 10–25 mm diam | Marshallia ramosa |
| 3 | Heads borne singly, 20–32 mm diam | Marshallia caespitosa |
| 4 | Leaves mostly cauline, blades ovate | Marshallia trinervia |
| 4 | Leaves mostly basal, blades elliptic, lanceolate, oblanceolate, or spatulate | > 5 |
| 5 | Phyllary apices obtuse; corollas white | Marshallia obovata |
| 5 | Phyllary apices acute; corollas pink | > 6 |
| 6 | Heads 1(–2), 26–45 mm diam | Marshallia grandiflora |
| 6 | Heads 2–5(–10), 22–37 mm diam | Marshallia mohrii |