Senecio integerrimus |
Senecio triangularis |
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lambstongue ragwort, mountain butterweed, one-stem butterweed, tall western groundsel, western groundsel |
arrow-leaf groundsel, arrow-leaf ragwort, arrowleaf butterweed, groundsel |
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Habit | Perennials (possibly biennials), (10–)20–70 cm (caudices buttonlike, roots fleshy-fibrous). | Perennials, (20–)50–120(–200) cm (caudices branched, ± woody). | ||||||||||||||||
Herbage | arachnose, loosely tomentose, or villous (hairs crisped, jointed), glabrescent. |
glabrous or sparsely floccose-tomentose when young. |
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Stems | single. |
single or loosely clustered. |
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Leaves | progressively reduced distally; ± petiolate; blades elliptic, lanceolate, linear, oblanceolate, rounded-deltate, or suborbiculate, 6–25 × 1–6 cm, bases ± tapered or truncate to cordate, margins entire or ± dentate (distal leaves sessile, bractlike). |
evenly distributed; petiolate; blades narrowly triangular, (3–)4–10+ × 2–6 cm, bases usually ± truncate, sometimes tapered, margins usually dentate, rarely subentire (distal leaves subsessile, smaller). |
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Ray florets | usually ± 8 or ± 13, sometimes 0; corolla laminae 6–15(–20) mm (usually yellow, ochroleucous to white in one variety). |
± 8; corolla laminae 9–15 mm. |
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Phyllaries | usually ± 13 or ± 21, rarely ± 8, (4–)5–12(–15) mm, tips usually black, sometimes green. |
(± 8) ± 13 (± 21), 6–10 mm, tips usually green, rarely black. |
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Calyculi | of 1–5+ linear to filiform bractlets (seldom more than 2 mm). |
of 2–6 bractlets (rarely more than 2 mm). |
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Heads | 6–20(–40+) in corymbiform arrays (peduncle of terminal head often shorter than others). |
10–30(–60) in corymbiform to subracemiform arrays. |
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Cypselae | usually glabrous, sometimes hirtellous (mostly on angles). |
glabrous. |
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2n | = 40, 80. |
= 40, 80. |
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Senecio integerrimus |
Senecio triangularis |
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Phenology | Flowering summer. | |||||||||||||||||
Habitat | Damp places, open woodlands, especially rocky stream banks in coniferous forests | |||||||||||||||||
Elevation | 100–3300 m (300–10800 ft) | |||||||||||||||||
Distribution |
CA; CO; IA; ID; KS; MN; MT; ND; NE; NM; NV; OR; SD; UT; WA; WY; AB; BC; MB; SK
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AK; AZ; CA; CO; ID; MT; NM; NV; OR; WA; WY; AB; BC; NT; YT; PH
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Discussion | Varieties 5 (5 in the flora). The varieties of Senecio integerrimus are distinguished by morphology and geography. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Plants of Senecio triangularis with narrow, subentire leaves that taper to the petioles are occasionally encountered in acid bogs in Oregon and Washington and less frequently elsewhere. They are regarded as edaphic variants; they have been recognized as var. angustifolius. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 20, p. 556. | FNA vol. 20, p. 566. | ||||||||||||||||
Parent taxa | Asteraceae > tribe Senecioneae > Senecio | Asteraceae > tribe Senecioneae > Senecio | ||||||||||||||||
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Subordinate taxa | ||||||||||||||||||
Synonyms | S. gibbonsii, S. saliens, S. triangularis var. angustifolius | |||||||||||||||||
Name authority | Nuttall: Gen. N. Amer. Pl. 2: 165. (1818) | Hooker: Fl. Bor.-Amer. 1: 332, plate 115. (1834) | ||||||||||||||||
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