Senecio triangularis |
Senecio erucifolius |
|
---|---|---|
arrow-leaf groundsel, arrow-leaf ragwort, arrowleaf butterweed, groundsel |
hoary ragwort |
|
Habit | Perennials, (20–)50–120(–200) cm (caudices branched, ± woody). | Perennials, 30–120 cm (rhizomes branched, sometimes producing stolons). |
Herbage | glabrous or sparsely floccose-tomentose when young. |
floccose-tomentose, unevenly glabrescent (persistently hairy on abaxial leaf faces). |
Stems | single or loosely clustered. |
usually single, sometimes loosely 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). |
± evenly distributed (basal and proximal sometimes withering before flowering); petiolate (proximal) or sessile; blades ovoid or oblong to spatulate (usually pinnatifid to pinnatisect, lobes ± lanceolate to linear), (3–)5–12 × (1.5–)2–4 cm, bases tapered to ± truncate, ultimate margins (often revolute) dentate or entire. |
Ray florets | ± 8; corolla laminae 9–15 mm. |
± 13; corolla laminae 12–15 mm. |
Phyllaries | (± 8) ± 13 (± 21), 6–10 mm, tips usually green, rarely black. |
± 13, 5–7 mm, tips green or greenish. |
Calyculi | of 2–6 bractlets (rarely more than 2 mm). |
of 4–6(–10) bractlets (lengths to 1/2 phyllaries). |
Heads | 10–30(–60) in corymbiform to subracemiform arrays. |
20–60 in corymbiform arrays. |
Cypselae | glabrous. |
hairy. |
2n | = 40, 80. |
|
Senecio triangularis |
Senecio erucifolius |
|
Phenology | Flowering summer. | Flowering summer. |
Habitat | Damp places, open woodlands, especially rocky stream banks in coniferous forests | Waste grounds |
Elevation | 100–3300 m (300–10800 ft) | 0–200+ m (0–700+ ft) |
Distribution |
AK; AZ; CA; CO; ID; MT; NM; NV; OR; WA; WY; AB; BC; NT; YT; PH
|
PA; Old World [Introduced in North America] |
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 erucifolius has been introduced occasionally around seaports and has persisted. At present, it appears to be uncommon and highly localized; it should be expected almost any place that its close relative, Senecio jacobaea, occurs. Senecio erucifolius was treated in Jacobaea by E. Wiebe (2000); see discussion under 53. S. jacobaea. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 566. | FNA vol. 20, p. 569. |
Parent taxa | Asteraceae > tribe Senecioneae > Senecio | Asteraceae > tribe Senecioneae > Senecio |
Sibling taxa | ||
Synonyms | S. gibbonsii, S. saliens, S. triangularis var. angustifolius | Jacobaea erucifolia |
Name authority | Hooker: Fl. Bor.-Amer. 1: 332, plate 115. (1834) | Linnaeus: Fl. Suec. ed. 2, 291. (1755) |
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