Tetragonotheca
nerveray
erect.
basal and/or cauline; mostly opposite;
petiolate, subpetiolate, or sessile (bases sometimes connate-perfoliate);
blades lanceolate, ovate, rhombic, or rounded-deltate, sometimes pinnatifid, ultimate margins usually toothed, faces glabrate, sparsely hispidulous, or puberulent, gland-dotted.
obpyramidal to hemispheric, 12–25+ mm diam.
conic, paleate (paleae persistent, lanceolate to lance-ovate, flat or weakly conduplicate, apices acute).
6–21+, pistillate, fertile;
corollas yellow (often with reddish nerves).
25–150+, bisexual, fertile;
corollas yellow, tubes (basally dilated) much shorter than ampliate, cylindric throats, lobes 5, deltate.
persistent, 10–25+ in ± 2 series (outer 4 broadly lanceolate, foliaceous, the inner ovate to lanceolate, smaller, more scarious, each subtending a ray floret).
radiate, borne singly or in loose, corymbiform arrays.
± ovoid or plumply 4- or 5-angled, finely 32–40-ribbed, sparsely strigose or glabrous;
pappi 0, or of 1–10+ subulate to acerose scales (to 0.5 mm), or of 16–30, ± spatulate scales (0.5–2 mm).
= 17.
Tetragonotheca
Species 4 (4 in the flora).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Pappi of 16–30, ± obovate to spatulate scales 0.5–2 mm | → 2 |
1. Pappi 0, or of 1–10+ subulate to acerose scales to 0.5 mm | → 3 |
2. Leaves mostly cauline (distal connate-perfoliate); ray florets 12–13, laminae 8–18 mm | T. ludoviciana |
2. Leaves mostly basal (cauline much smaller, none connate-perfoliate); ray florets 16–21+, laminae 20–30+ mm | T. repanda |
3. Stems sparsely tomentulose or glabrous (nodes usually auriculate-appendaged); ray laminae 10–18 mm; cypselae ± quadrate, 2.5–4 mm | T. texana |
3. Stems patently to retrorsely ± villous; ray laminae 20–40+ mm; cypselae ± ovoid, 4–6 mm | T. helianthoides |
WildflowerSearch
iNaturalist
USDA Plants Database
