Helianthella
Fl. N. Amer. 2: 333. 1842.
| Taxon | Illustrator ⠉ | |
|---|---|---|
 | Phoebanthus grandiflorus Helianthella quinquenervis Flourensia cernua | Marjorie C. Leggitt Yevonn Wilson-Ramsey Barbara Alongi |
Perennials, 20–150 cm. Stems erect, usually branched. Leaves basal and cauline; opposite (proximal) and alternate; usually petiolate (at least proximal); blades (usually 3-nerved or 5-nerved from at or near bases) elliptic, lanceolate, lance-linear, linear, oblanceolate, ovate, ovatelanceolate, or spatulate, bases mostly cuneate, margins entire, faces glabrous or hairy. Heads radiate, borne singly or (2–15+) in corymbiform arrays. Involucres campanulate to hemispheric or broader, 10–50 mm diam. Phyllaries persistent, 22–32+ in ± 3 series (mostly deltate-ovate or ovate to lanceolate, linear, or oblong, subequal or unequal, outer sometimes foliaceous). Receptacles ± convex, paleate (paleae falling with cypselae, conduplicate, scarious or chartaceous). Ray-florets 8–21, neuter; corollas ± yellow. Disc-florets 30–200+, bisexual, fertile; corollas yellow or purple to brown, tubes shorter than or equaling throats, lobes 5, deltate (abaxially hairy). Cypselae (brownish) ± compressed, obovate to obcordate (margins usually ± winged, usually ± ciliate, faces glabrous or strigose); pappi 0, or persistent, of 2 ± subulate scales plus 0–4+ shorter, lacerate scales (sometimes all ± connate). x = 15.
Distribution
w North America, n Mexico
Discussion
Species 9 (6 in the flora).
Selected References
Lower Taxa
Key
| 1 | Heads 5–15+; phyllaries mostly deltate-ovate to oblong (unequal to subequal); ray laminae 8–14+ mm (usually little surpassing discs); disc corollas purple to brown | Helianthella microcephala |
| 1 | Heads 1(–3+); phyllaries mostly lanceolate, lance-linear, lance-oblong, or ovate (subequal, outer sometimes foliaceous); ray laminae (11–)15–30(–45+) mm; disc corollas yellow | > 2 |
| 2 | Heads ± nodding; paleae scarious, relatively soft | > 3 |
| 2 | Heads erect; paleae chartaceous, relatively firm | > 4 |
| 3 | Plants 20–50 cm; leaf blades oblanceolate or spatulate (broadest distal to middles, not leathery), faces rough-pubescent; involucres 15–20 mm diam.; ray florets 8–14 (corollas pale yellow) | Helianthella parryi |
| 3 | Plants usually 50–150 cm; leaf blades elliptic to ovate-lanceolate (broadest near middles, leathery), faces sparsely hirsute or glabrous; involucres 40–50 diam.; ray florets (13–)21 (corollas bright yellow) | Helianthella quinquenervis |
| 4 | Cauline leaves: largest at mid stems; faces of cypselae strigose | Helianthella uniflora |
| 4 | Cauline leaves: largest proximal to mid stems; faces of cypselae usually glabrous | > 5 |
| 5 | Involucres 15–20(–25) mm diam. (sometimes 2–3 outer phyllaries foliaceous); cypselae strongly compressed | Helianthella californica |
| 5 | Involucres 25–40 mm diam. (usually 3–4+ outer phyllaries foliaceous, 3–10+ cm); cypselae weakly compressed (plump in middles, thin at edges) | Helianthella castanea |
"broader" is not a number.