Thelesperma megapotamicum |
Thelesperma subnudum |
Thelesperma simplicifolium |
|
---|---|---|---|
green threads, Hopi tea, Hopi tea greenthread, rayless greenthread |
hairy greenthread, Navajo tea |
Edwards Plateau greenthread, slender greenthread |
|
Habit | Perennials or subshrubs, (20–)30–80+ cm. | Perennials, 10–30(–40+) cm (caudices often woody). | Perennials or subshrubs (may flower first year), (20–)30–70+ cm. |
Cauline leaves | ± scattered over proximal 1/2–3/4 of plant heights, internodes mostly 40–100 mm; lobes mostly linear to filiform, sometimes oblanceolate, 20–40(–50+) × 0.5–1(–2.5) mm. |
mostly crowded over proximal 1/4(–1/2) of plant heights, internodes mostly 1–5(–35 mm); lobes mostly oblanceolate to linear, (5–)10–35(–45+) × (1–)2–3(–5) mm. |
± scattered over proximal 3/4+ of plant heights, internodes mostly 45–95 mm; lobes mostly linear to filiform, sometimes oblanceolate, (5–)15–45(–60) × 0.5–1(–2) mm. |
Ray florets | 0. |
0, or 8; laminae yellow, (6–)12–20+ mm. |
usually 8, rarely 0; laminae yellow, 9–15(–20+) mm. |
Disc corollas | yellow, often with red-brown nerves, throats shorter than lobes. |
yellow, sometimes with red-brown nerves, throats equal to or longer than lobes. |
yellow with red-brown nerves, throats equal to or longer than lobes. |
Calyculi | of 3–5+ ovate to oblong bractlets 1–2(–3) mm. |
of 7–9 deltate to lance-linear bractlets 2–4+ mm. |
of 6–8+ linear to subulate bractlets 1–3+ mm. |
Cypselae | 5–8 mm; pappi 1–2(–3) mm. |
5–7 mm; pappi usually 0, rarely 0.1–0.5 mm. |
3–4 mm; pappi usually 0, rarely 0.1–0.3+ mm. |
2n | = 22, 44. |
= 22, 24. |
= 20. |
Thelesperma megapotamicum |
Thelesperma subnudum |
Thelesperma simplicifolium |
|
Phenology | Flowering (Apr–)May–Oct. | Flowering May–Sep. | Flowering Apr–Jul(–Oct). |
Habitat | Disturbed places on sands or clays, oak/juniper woodlands, desert scrub, yellow-pine forests | Openings in pinyon/juniper or yellow-pine forests, often on talus or "balds" | Openings in oak/juniper woodlands or desert scrub, usually on limestone |
Elevation | 300–2900 m (1000–9500 ft) | 1000–2900 m (3300–9500 ft) | 100–1500 m (300–4900 ft) |
Distribution |
AR; AZ; CO; KS; NE; NM; OK; SD; TX; UT; WY; South America; Mexico (Chihuahua, Coahuila)
|
AZ; CO; MT; ND; NM; NV; UT; WY; AB
|
TX; Mexico (Chihuahua, Coahuila, Nuevo León, Tamaulipas)
|
Discussion | Thelesperma megapotamicum sometimes persists after plantings outside its natural range in the flora area and may become established (e.g., in California). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
As here circumscribed, Thelesperma subnudum includes plants that have been treated as distinct species and/or varieties (some of which have been treated as of conservation concern). See C. J. Hansen et al. (2002) for an alternate interpretation of T. subnudum. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Thelesperma simplicifolium is used in roadside plantings and may be encountered as a waif outside its natural range in the flora area (e.g., in California). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 21, p. 202. | FNA vol. 21, p. 201. | FNA vol. 21, p. 201. |
Parent taxa | Asteraceae > tribe Heliantheae > subtribe Coreopsidinae > Thelesperma | Asteraceae > tribe Heliantheae > subtribe Coreopsidinae > Thelesperma | Asteraceae > tribe Heliantheae > subtribe Coreopsidinae > Thelesperma |
Sibling taxa | |||
Synonyms | Bidens megapotamica, T. gracile | T. caespitosum, T. marginatum, T. pubescens, T. pubescens var. caespitosum, T. subnudum var. alpinum, T. subnudum var. marginatum, T. subnudum var. pubescens, T. windhamii | Cosmidium simplicifolium, T. curvicarpum |
Name authority | (Sprengel) Kuntze: Revis. Gen. Pl. 3(2): 182. (1898) | A. Gray: Proc. Amer. Acad. Arts 10: 72. (1874) | (A. Gray) A. Gray: Hooker’s J. Bot. Kew Gard. Misc. 1: 252. (1849) |
Web links | |||