Senecio flaccidus

Subshrubs or shrubs, (30–)40–120+ cm (taproots forming woody crowns). Herbage glabrous or ± lanate-tomentose. Stems usually multiple (little branched, arching-erect). Leaves ± evenly distributed; sessile or obscurely petiolate; blades narrowly linear to filiform (or pinnatifid, the segments linear to filiform), 3–10(–12) cm, bases ± linear, ultimate margins entire or remotely toothed (fascicles of smaller leaves sometimes borne in axils of larger leaves). Heads (1–)3–10(–20+) in corymbiform or subcorymbiform clusters, often gathered in larger, showy arrays (involucres campanulate or cylindric). Calyculi usually of 3–5+ bractlets (lengths often to 1/2+ phyllaries), sometimes 0. Phyllaries ± 13 or ± 21+, 5–10(–12) mm, tips green or minutely black. Ray florets usually ± 8 or ± 13, sometimes ± 21; corolla laminae 10–15(–20) mm (mostly yellow, sometimes ochroleucous). Cypselae hairy. 2n = 40.

Distribution

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• Legacy Map

w United States, Mexico.

Discussion

Varieties 3 (3 in the flora).

The varieties of Senecio flaccidus are distinguished by morphologic tendencies and geography. The species occurs southward to central Mexico; a sound understanding of the infraspecific taxonomy must await revisionary studies that include the Mexican plants.

Selected References

None.

Lower Taxa

Senecio flaccidus var. douglasii, Senecio flaccidus var. flaccidus, Senecio flaccidus var. monoensis

Key

1	Herbage usually tomentose (hairs whitish), sometimes unevenly glabrescent; bractlets of calyculi minute or 0; involucres cylindric or ± campanulate; phyllaries ± 13 or ± 21, 5–8+ mm	Senecio flaccidus var. flaccidus
1	Herbage ± tomentose, glabrate, or glabrous; bractlets of calyculi well developed (lengths mostly 1/3 – 1/2 phyllaries); involucres ± campanulate; phyllaries ± 21, 7–12 mm	> 2
2	Plants usually ± tomentose (usually with persistent, uneven grayish tomentum), sometimes unevenly glabrescent; California w of crests of Sierra Nevada and related ranges	Senecio flaccidus var. douglasii
2	Plants glabrate or glabrous; California deserts e of crest of Sierra Nevada and eastward	Senecio flaccidus var. monoensis