Senecio pattersonensis |
Senecio riddellii |
|
---|---|---|
Mono ragwort, Mount Patterson senecio |
Riddell's groundsel, Riddell's ragwort |
|
Habit | Perennials, to 10 cm (rhizomes branching). | Subshrubs, 30–100 cm (taproots forming woody crowns). |
Herbage | (sometimes reddish-tinged, especially proximally) glabrous. |
glabrous. |
Stems | 1–3 (arching upward). |
usually multiple (branching upward). |
Leaves | evenly distributed (proximal often withering before flowering); obscurely petiolate or sessile; blades oblanceolate to lance-linear (sometimes with 1–2 lateral lobes), 2–4 cm × 3–5 mm, bases subdecurrent, weakly clasping, margins entire or wavy (often revolute). |
± evenly distributed (proximal often withering before flowering, pendulous); sessile or obscurely petiolate; blades linear-filiform (or irregularly pinnately divided into linear-filiform lobes), blades or lobes 4–9 cm × 1–5 mm, bases ± linear, ultimate margins entire. |
Ray florets | ± 8; corolla laminae 5–10 mm. |
± 8; corolla laminae (often falling early) 8–10 mm. |
Phyllaries | ± 13, 5–7(–8) mm. |
± 13, 7–10(–12+) mm, tips green. |
Calyculi | of 3–5+ (inconspicuous) bractlets. |
usually of 3–8+ lance-linear to filiform bractlets (lengths 1/10–1/3 phyllaries). |
Heads | 1(–4). |
5–20+ in close, corymbiform arrays (involucres campanulate, 7–10 mm diam.). |
Cypselae | glabrous. |
hirtellous. |
2n | = 40. |
|
Senecio pattersonensis |
Senecio riddellii |
|
Phenology | Flowering summer. | Flowering mostly mid summer–fall, occasionally spring. |
Habitat | Talus slopes | Sandy or rocky open sites, especially drying, open, flood plains |
Elevation | 3000–3700 m (9800–12100 ft) | 600–2500 m (2000–8200 ft) |
Distribution |
CA; NV |
AZ; CO; KS; NE; NM; OK; SD; TX; WY
|
Discussion | Of conservation concern. Senecio pattersonensis has the aspect of a depauperate S. fremontii with notably narrow leaves. Some plants in collections appear to be intergrades with S. spartioides. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Senecio riddellii intergrades morphologically with S. spartioides. Typically, the former has larger heads with campanulate involucres 7–10 mm diam.; the latter has cylindric involucres rarely more than 6 mm diam. Senecio riddellii is poisonous to livestock. It is now locally scarce because of efforts to eradicate it. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 564. | FNA vol. 20, p. 560. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | S. revolutus | S. filifolius var. fremontii, S. riddellii var. parksii, S. spartioides var. fremontii, S. spartioides var. parksii, S. spartioides var. riddellii |
Name authority | Hoover: Leafl. W. Bot. 5: 60. (1947) | Torrey & A. Gray: Fl. N. Amer. 2: 444. (1843) |
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