Thymophylla pentachaeta |
Thymophylla |
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five-needle pricklyleaf |
pricklyleaf |
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Habit | Perennials or subshrubs, ± grayish to green, to 15(–25) cm, usually puberulent to canescent, sometimes glabrescent or glabrous. | Annuals, perennials, subshrubs, or shrubs, (1–)5–30 cm. | ||||||||||||||||||||||||||||||||||||||||
Stems | erect or spreading. |
erect to spreading or decumbent, branched from bases or ± throughout. |
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Leaves | mostly opposite; blades mostly pinnately lobed, 6–28+ mm overall, lobes 3–11 linear to filiform (usually stiff, setiform). |
cauline; opposite or alternate; petiolate or sessile; blades often pinnately lobed, blades or lobes spatulate to linear or filiform, ultimate margins entire or toothed, faces glabrous or arachnose, canescent, floccose, lanate, puberulent, or tomentose (bases little, if at all, bristly-ciliate, oil-glands scattered in laminae or submarginal). |
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Peduncles | 20–100 mm, puberulent or glabrous. |
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Involucres | obconic to campanulate or hemispheric, 4–6 mm. |
campanulate to obconic, 2–7 mm diam. |
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Receptacles | convex, smooth or ± pitted, epaleate. |
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Ray florets | (8–)12–21; corollas yellow to orange-yellow, laminae 2–6(–8) × 1–3 mm. |
usually 5, 8, 13, or 21, pistillate, fertile; corollas usually yellow to orange, rarely white. |
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Disc florets | 16–40 or 50–80; corollas yellow, 2–4 mm (tending to zygomorphy in peripheral florets in some plants). |
16–100+, bisexual, fertile; corollas yellow to orange, tubes shorter than ± cylindric throats, lobes 5, deltate. |
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Phyllaries | 12–21, margins of outer distinct 1/5 to nearly all their lengths, abaxial faces puberulent or glabrous. |
persistent, 8–13(–22) in ± 2 series (strongly connate 2/3–7/8+ their lengths, seldom with outer margins distinct more than 1/2 their lengths, exceptions: T. aurea, T. pentachaeta var. belenidium), usually bearing oil-glands. |
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Calyculi | 0, or of 1–5 deltate bractlets, lengths less than 1/2 phyllaries. |
0 or of 1–8 deltate to linear bractlets (bearing oil-glands). |
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Heads | usually radiate, sometimes discoid or radiant, borne singly. |
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Cypselae | 2–3 mm; pappi of 10 erose and/or aristate scales mostly 1–3 mm. |
obpyramidal, obconic, or cylindro-clavate, glabrous or sparsely strigillose; pappi persistent, coroniform or of 10(–20) distinct scales (each scale erose, or 1–5-aristate, or a fascicle of 5–9 basally connate bristles). |
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x | = 8. |
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Thymophylla pentachaeta |
Thymophylla |
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Distribution |
AZ; CA; NM; NV; TX; UT; Mexico [Introduced(?) in South America (Argentina)]
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sw United States; Mexico [Introduced in West Indies, South America, Asia, Africa] |
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Discussion | Varieties 4 (4 in the flora). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Species 13 (8 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. 241. | FNA vol. 21, p. 239. | ||||||||||||||||||||||||||||||||||||||||
Parent taxa | Asteraceae > tribe Heliantheae > subtribe Pectidinae > Thymophylla | Asteraceae > tribe Heliantheae > subtribe Pectidinae | ||||||||||||||||||||||||||||||||||||||||
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Synonyms | Hymenatherum pentachaetum, Dyssodia pentachaeta | Dyssodia section Gnaphalopsis, Dyssodia section Hymenatherum, Hymenatherum | ||||||||||||||||||||||||||||||||||||||||
Name authority | (de Candolle) Small: Fl. S.E. U.S., 1295, 1341. (1903) | Lagasca: Gen. Sp. Pl., 25. (1816) | ||||||||||||||||||||||||||||||||||||||||
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