Senecio triangularis |
Senecio wootonii |
|
---|---|---|
arrow-leaf groundsel, arrow-leaf ragwort, arrowleaf butterweed, groundsel |
Wooton's butterweed, Wooton's ragwort |
|
Habit | Perennials, (20–)50–120(–200) cm (caudices branched, ± woody). | Perennials, (15–)20–45(–60) cm (caudices erect or weakly spreading). |
Herbage | glabrous or sparsely floccose-tomentose when young. |
nearly always glaucous, glabrous. |
Stems | single or loosely clustered. |
single or clustered. |
Leaves | 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). |
(thickish and turgid) progressively reduced distally; petiolate; blades ovate or obovate to lanceolate, 4–9(–15+) × 1.5–3(–4+) cm, bases tapered, margins wavy or subentire (often with callous denticles; mid and distal leaves sessile, bractlike). |
Ray florets | ± 8; corolla laminae 9–15 mm. |
8–10; corolla laminae 4–10 mm. |
Phyllaries | (± 8) ± 13 (± 21), 6–10 mm, tips usually green, rarely black. |
± 13 (± 21), 6–9 mm, tips green to brownish (not blackened). |
Calyculi | of 2–6 bractlets (rarely more than 2 mm). |
of 1–3+ oblong to lance-linear bractlets (less than 3 mm). |
Heads | 10–30(–60) in corymbiform to subracemiform arrays. |
(3–)8–24+ in corymbiform arrays. |
Cypselae | glabrous. |
glabrous. |
2n | = 40, 80. |
= 40. |
Senecio triangularis |
Senecio wootonii |
|
Phenology | Flowering summer. | Flowering spring–summer. |
Habitat | Damp places, open woodlands, especially rocky stream banks in coniferous forests | Damp or drying sites, often in rocky, moderately disturbed sites |
Elevation | 100–3300 m (300–10800 ft) | 2000–3500 m (6600–11500 ft) |
Distribution |
AK; AZ; CA; CO; ID; MT; NM; NV; OR; WA; WY; AB; BC; NT; YT; PH
|
AZ; CO; NM; TX; Mexico
|
Discussion | 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.) |
Senecio wootonii reaches its southern limit in Coahuila and Chihuahua, Mexico; farther south, it is replaced by S. toluccanus de Candolle, a similar, larger, more robust species. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 566. | FNA vol. 20, p. 554. |
Parent taxa | Asteraceae > tribe Senecioneae > Senecio | Asteraceae > tribe Senecioneae > Senecio |
Sibling taxa | ||
Synonyms | S. gibbonsii, S. saliens, S. triangularis var. angustifolius | S. anacletus |
Name authority | Hooker: Fl. Bor.-Amer. 1: 332, plate 115. (1834) | Greene: Bull. Torrey Bot. Club 25: 122, plate 331, figs. 1, 2. (1898) |
Web links |