Thymophylla tenuiloba |
Thymophylla acerosa |
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bristleleaf pricklyleaf, Dahlburg-daisy, shooting star |
pricklyleaf dogweed |
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Habit | Annuals (rarely persisting), green, to 30 cm, glabrous or sparsely hirtellous. | Subshrubs or shrubs, green, to 25 cm, usually puberulent, sometimes glabrescent, rarely glabrous. | ||||||||||||
Stems | decumbent to erect. |
erect (branched from bases). |
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Leaves | mostly alternate (sometimes opposite at 1–3 proximal nodes); blades usually lobed, 12–28 mm overall, lobes 7–15, linear to filiform, pliable (blades mostly not lobed in var. wrightii). |
mostly opposite; blades not lobed, linear to acerose, 10–18 mm. |
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Peduncles | 30–80 mm, glabrous or hirtellous. |
0–10 mm, puberulent or glabrous. |
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Involucres | obconic, 5–7 mm. |
campanulate to cylindric, 5–7 mm. |
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Ray florets | 10–21; corollas yellow-orange, laminae 4–10 × 1.5–3 mm. |
7–8; corollas lemon-yellow, laminae 5–6 × 2–3 mm. |
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Disc florets | 50–100+; corollas yellow, 2.5–4.5 mm (peripheral ± zygomorphic in some plants). |
18–25+; corollas pale yellow, 3–4 mm. |
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Phyllaries | 12–22, margins of outer distinct less than 1/5 their lengths, abaxial faces glabrous or sparsely hirtellous. |
ca. 13, margins of outer distinct less than 1/6 their lengths, abaxial faces puberulent or glabrous. |
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Calyculi | of 3–8 deltate to subulate bractlets, lengths less than 1/2 phyllaries. |
of 5 lance-linear bractlets, lengths 1/2+ phyllaries. |
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Cypselae | 2–3.5 mm; pappi of erose and/or aristate scales 0.7–3.5 mm. |
3–3.5 mm; pappi of ca. 20 scales (each a fascicle of 3–5 bristles), 3–4 mm. |
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2n | = 16, 24. |
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Thymophylla tenuiloba |
Thymophylla acerosa |
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Phenology | Flowering through the year, mostly summer–fall. | |||||||||||||
Habitat | Calcareous outcrops, gypseous soils | |||||||||||||
Elevation | 1000–2000+ m (3300–6600+ ft) | |||||||||||||
Distribution |
TX; n Mexico
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AZ; NM; NV; TX; UT; Mexico
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Discussion | Varieties 4 (4 in the flora). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 21, p. 242. | FNA vol. 21, p. 241. | ||||||||||||
Parent taxa | Asteraceae > tribe Heliantheae > subtribe Pectidinae > Thymophylla | Asteraceae > tribe Heliantheae > subtribe Pectidinae > Thymophylla | ||||||||||||
Sibling taxa | ||||||||||||||
Subordinate taxa | ||||||||||||||
Synonyms | Hymenatherum tenuilobum, Dyssodia tenuiloba | Dyssodia acerosa | ||||||||||||
Name authority | (de Candolle) Small: Fl. S.E. U.S., 1295, 1341. (1903) | (de Candolle) Strother: Sida 11: 376. (1986) | ||||||||||||
Web links |