Senecio atratus |
Senecio flaccidus |
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tall blacktip ragwort |
Douglas' groundsel, Mono groundsel, shrubby butterweed, shrubby ragwort, threadleaf groundsel, threadleaf ragwort |
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Habit | Perennials, (20–)35–70(–80+) cm (rhizomes or caudices branched, erect to weakly creeping). | Subshrubs or shrubs, (30–)40–120+ cm (taproots forming woody crowns). | ||||||||
Herbage | floccose-tomentose to canescent, sometimes unevenly glabrescent. |
glabrous or ± lanate-tomentose. |
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Stems | 1–(2–5). |
usually multiple (little branched, arching-erect). |
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Leaves | progressively reduced distally; petiolate; blades oblong-ovate to oblanceolate, (5–)10–30 × 1.5–4(–6) cm, bases tapered, margins dentate (denticles, dark, callous; mid leaves similar, sessile, smaller; distal leaves bractlike). |
± evenly distributed; sessile or obscurely petiolate; blades narrowly linear to filiform (or pinnatifid, the segments linear to filiform), 3–10(–12) cm, bases ± linear, ultimate margins entire or remotely toothed (fascicles of smaller leaves sometimes borne in axils of larger leaves). |
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Ray florets | (± 3) ± 5; corolla laminae 5–8 mm. |
usually ± 8 or ± 13, sometimes ± 21; corolla laminae 10–15(–20) mm (mostly yellow, sometimes ochroleucous). |
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Phyllaries | (± 5) ± 8, 6–8 mm, tips black. |
± 13 or ± 21+, 5–10(–12) mm, tips green or minutely black. |
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Calyculi | of 2–5 linear bractlets (lengths to 1/3 phyllaries). |
usually of 3–5+ bractlets (lengths often to 1/2+ phyllaries), sometimes 0. |
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Heads | 20–60+ in corymbiform or subpaniculiform arrays. |
(1–)3–10(–20+) in corymbiform or subcorymbiform clusters, often gathered in larger, showy arrays (involucres campanulate or cylindric). |
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Cypselae | glabrous. |
hairy. |
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2n | = 40. (A report of 2n = 46 is presumably erroneous.) |
= 40. |
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Senecio atratus |
Senecio flaccidus |
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Phenology | Flowering late spring–early fall. | |||||||||
Habitat | Dry or drying, rocky or sandy sites in coniferous areas, especially sites with frequent disturbance | |||||||||
Elevation | 2800–4000 m (9200–13100 ft) | |||||||||
Distribution |
CO; NM; UT; WY
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AZ; CA; CO; KS; NM; NV; OK; TX; UT; Mexico
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Discussion | Varieties 3 (3 in the flora). The varieties of Senecio flaccidus are distinguished by morphologic tendencies and geography. The species occurs southward to central Mexico; a sound understanding of the infraspecific taxonomy must await revisionary studies that include the Mexican plants. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 20, p. 554. | FNA vol. 20, p. 558. | ||||||||
Parent taxa | Asteraceae > tribe Senecioneae > Senecio | Asteraceae > tribe Senecioneae > Senecio | ||||||||
Sibling taxa | ||||||||||
Subordinate taxa | ||||||||||
Synonyms | S. atratus var. milleflorus, S. milleflorus | |||||||||
Name authority | Greene: Pittonia 3: 105. (1896) | Lessing: Linnaea 5: 161. (1830) | ||||||||
Web links |