Thymophylla pentachaeta

Perennials or subshrubs, ± grayish to green, to 15(–25) cm, usually puberulent to canescent, sometimes glabrescent or glabrous. Stems erect or spreading. Leaves mostly opposite; blades mostly pinnately lobed, 6–28+ mm overall, lobes 3–11 linear to filiform (usually stiff, setiform). Peduncles 20–100 mm, puberulent or glabrous. Calyculi 0, or of 1–5 deltate bractlets, lengths less than 1/2 phyllaries. Involucres obconic to campanulate or hemispheric, 4–6 mm. Phyllaries 12–21, margins of outer distinct 1/5 to nearly all their lengths, abaxial faces puberulent or glabrous. Ray florets (8–)12–21; corollas yellow to orange-yellow, laminae 2–6(–8) × 1–3 mm. Disc florets 16–40 or 50–80; corollas yellow, 2–4 mm (tending to zygomorphy in peripheral florets in some plants). Cypselae 2–3 mm; pappi of 10 erose and/or aristate scales mostly 1–3 mm.

Distribution

• Generated Map
• Legacy Map

sw United States, Mexico, introduced(?) in South America (Argentina).

Discussion

Varieties 4 (4 in the flora).

Selected References

None.

Lower Taxa

Thymophylla pentachaeta var. belenidium, Thymophylla pentachaeta var. hartwegii, Thymophylla pentachaeta var. pentachaeta, Thymophylla pentachaeta var. puberula

Key

1	Involucres cylindric, 2–3.5 mm diam.; disc florets 16–40	Thymophylla pentachaeta var. hartwegii
1	Involucres obconic, campanulate, or hemispheric, mostly 4–5 mm diam.; disc florets 50–80	> 2
2	Peduncles 20–50 mm; margins of outer phyllaries distinct almost to bases	Thymophylla pentachaeta var. belenidium
2	Peduncles (40–)50–100 mm; margins of outer phyllaries distinct less ca. 1/2 or ca. 1/3 their lengths	> 3
3	Leaf lobes mostly 9–11; phyllaries usually glabrous or glabrescent, rarely hairy	Thymophylla pentachaeta var. pentachaeta
3	Leaf lobes mostly 5–7(–10); phyllaries densely puberulent	Thymophylla pentachaeta var. puberula