Thelesperma filifolium |
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Navajo tea, plains greenthread, stiff greenthread |
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Habit | Annuals (sometimes persisting), 10–40(–70+) cm. |
Cauline leaves | crowded to ± scattered over proximal 1/2–3/4 of plant heights, internodes mostly 10–35(–50+) mm; lobes mostly linear to filiform, sometimes oblanceolate, 5–30(–55+) × 0.5–1(–3+) mm. |
Ray florets | 8; laminae yellow to golden yellow (sometimes proximally suffused with red-brown), 12–20+ mm. |
Disc corollas | red-brown or yellow with red-brown nerves, throats shorter than lobes. |
Calyculi | of 7–8+ linear to narrowly triangular bractlets (2–)4–8+ mm. |
Cypselae | 3.5–4+ mm; pappi 0.5–1(–2+) mm. |
2n | = 16, 18. |
Thelesperma filifolium |
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Phenology | Flowering Mar–Aug(–Oct). |
Habitat | Disturbed sites on clays or sandy soils, rocky slopes, often on limestone |
Elevation | 10–2200 m (0–7200 ft) |
Distribution |
AR; CO; KS; LA; MO; MS; NE; NM; OK; SD; TX; WY; Mexico (Nuevo León)
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Discussion | As here circumscribed, Thelesperma filifolium includes plants that others have treated as a distinct species or variety: T. intermedium or T. filifolium var. intermedium, characterized as plants mostly 10–40 cm (versus taller); internodes “relatively short” (versus longer); calyculus bractlets mostly 1/4–1/2 lengths of phyllaries (versus more than 1/2 as long); ray corollas yellow (versus “golden yellow”); disc corollas yellow (versus sometimes red-brown); distribution mostly north and west of the typical form (Colorado, Kansas, Nebraska, New Mexico, w Oklahoma, South Dakota, c and w Texas, Wyoming). According to A. Cronquist (1980), Thelesperma trifidum (Poiret) Britton has been misapplied (e.g., M. L. Fernald 1950) to T. filifolium. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 21, p. 202. |
Parent taxa | Asteraceae > tribe Heliantheae > subtribe Coreopsidinae > Thelesperma |
Sibling taxa | |
Synonyms | Coreopsis filifolia, T. filifolium var. intermedium, T. intermedium |
Name authority | (Hooker) A. Gray: Hooker’s J. Bot. Kew Gard. Misc. 1: 252. (1849) |
Web links |