Senecio aronicoides |
Senecio atratus |
|
---|---|---|
butterweed, rayless groundsel, rayless ragwort |
tall blacktip ragwort |
|
Habit | Perennials (biennials?), 30–90 cm (caudices buttonlike, roots unbranched, fleshy-fibrous). | Perennials, (20–)35–70(–80+) cm (rhizomes or caudices branched, erect to weakly creeping). |
Herbage | loosely and sparsely arachnose to finely tomentose, unevenly glabrescent. |
floccose-tomentose to canescent, sometimes unevenly glabrescent. |
Stems | single. |
1–(2–5). |
Leaves | progressively reduced distally; petiolate; blades ovate or oblanceolate to oblong, 7–20 × 2–3 cm, bases broadly to narrowly tapered, margins repand-denticulate or sublaciniate to subentire (mid and distal leaves sessile, smaller, weakly clasping). |
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). |
Ray florets | 0 or 1–2; corolla laminae 4–7 mm. |
(± 3) ± 5; corolla laminae 5–8 mm. |
Phyllaries | ± 8 or ± 13, 4–8 mm, tips green or black. |
(± 5) ± 8, 6–8 mm, tips black. |
Calyculi | 0 or of 1–3+ oblong to linear bractlets (seldom more than 1.5 mm). |
of 2–5 linear bractlets (lengths to 1/3 phyllaries). |
Heads | (6–)15–30+ in corymbiform arrays. |
20–60+ in corymbiform or subpaniculiform arrays. |
Cypselae | glabrous. |
glabrous. |
2n | = 40. |
= 40. (A report of 2n = 46 is presumably erroneous.) |
Senecio aronicoides |
Senecio atratus |
|
Phenology | Flowering spring–early summer. | Flowering late spring–early fall. |
Habitat | Dry or drying sites in open woodlands, upper foothills and montane forests | Dry or drying, rocky or sandy sites in coniferous areas, especially sites with frequent disturbance |
Elevation | 800–2500 m (2600–8200 ft) | 2800–4000 m (9200–13100 ft) |
Distribution |
CA; OR
|
CO; NM; UT; WY
|
Source | FNA vol. 20, p. 556. | FNA vol. 20, p. 554. |
Parent taxa | Asteraceae > tribe Senecioneae > Senecio | Asteraceae > tribe Senecioneae > Senecio |
Sibling taxa | ||
Synonyms | S. leptolepis, S. rawsonianus | S. atratus var. milleflorus, S. milleflorus |
Name authority | de Candolle: in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 6: 426. (1838) | Greene: Pittonia 3: 105. (1896) |
Web links |