Senecio triangularis |
Senecio viscosus |
|
---|---|---|
arrow-leaf groundsel, arrow-leaf ragwort, arrowleaf butterweed, groundsel |
stickly groundsel, sticky ragwort |
|
Habit | Perennials, (20–)50–120(–200) cm (caudices branched, ± woody). | Annuals, (10–)20–40(–60) cm (taprooted). |
Herbage | glabrous or sparsely floccose-tomentose when young. |
densely fetid-viscid (hairs glandular). |
Stems | single or loosely clustered. |
single. |
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; petiolate; blades obovate to oblong (pinnately dissected to pinnatifid), 2–7 × 1.5–4 cm, bases tapered or ± truncate, ultimate margins wavy or crenate-dentate (distal leaves sessile, smaller, ± clasping). |
Ray florets | ± 8; corolla laminae 9–15 mm. |
± 13; corolla laminae 1–2 mm (usually coiled, scarcely surpassing phyllaries). |
Phyllaries | (± 8) ± 13 (± 21), 6–10 mm, tips usually green, rarely black. |
(± 13) ± 21, 5–7 mm, tips black. |
Calyculi | of 2–6 bractlets (rarely more than 2 mm). |
of 2–5 bractlets (largest to 4 mm). |
Heads | 10–30(–60) in corymbiform to subracemiform arrays. |
(1–)3–8(–30) in irregular, corymbiform arrays. |
Cypselae | glabrous. |
usually glabrous, sometimes hairy. |
2n | = 40, 80. |
= 40. |
Senecio triangularis |
Senecio viscosus |
|
Phenology | Flowering summer. | Flowering spring–fall. |
Habitat | Damp places, open woodlands, especially rocky stream banks in coniferous forests | Disturbed sites, especially open sandy or gravelly places |
Elevation | 100–3300 m (300–10800 ft) | 1–300 m (0–1000 ft) |
Distribution |
AK; AZ; CA; CO; ID; MT; NM; NV; OR; WA; WY; AB; BC; NT; YT; PH
|
CT; IL; MA; ME; MN; NH; NJ; NY; PA; RI; WI; AB; BC; MB; NB; NF; NS; ON; PE; QC; SK; SPM; Eurasia [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 viscosus is a smelly, Eurasian weed now widely scattered in areas of cool damp climates, often as a casual waif. The viscid hairs trap wind-blown particles of sand, dust, and soot, which give the surfaces varying textures and colors. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 566. | FNA vol. 20, p. 562. |
Parent taxa | Asteraceae > tribe Senecioneae > Senecio | Asteraceae > tribe Senecioneae > Senecio |
Sibling taxa | ||
Synonyms | S. gibbonsii, S. saliens, S. triangularis var. angustifolius | |
Name authority | Hooker: Fl. Bor.-Amer. 1: 332, plate 115. (1834) | Linnaeus: Sp. Pl. 2: 868. (1753) |
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