Senecio mohavensis

Torrey & A. Gray

in A. Gray et al., Syn. Fl. N. Amer. 1(2): 446. 1884.

Treatment appears in FNA Volume 20. Treatment on page 563. Mentioned on page 542, 548.

Annuals, 10–30(–40) cm (taproots often twisted). Herbage (sometimes purple-tinged) glabrous. Stems usually 1 (freely branching upward). Leaves equally distributed; petiolate; blades ovate to obovate, 2–6 × 0.5–2(–4) cm, bases tapered, margins coarsely lobed or irregularly dentate (mid and distal leaves similar, bases expanded, truncate to cordate, clasping, 1–2 cm across). Heads 3–10 in loose, cymiform arrays. Calyculi of 3–5+ lance-linear bractlets. Phyllaries ± 8 or ± 13, 6–7 mm, tips green. Ray florets 0 or 1–3+; corolla laminae 0.1–1 mm (little expanded, barely, if at all, surpassing phyllaries; sometimes laminae 0 and heads perhaps technically disciform). Cypselae hairy. 2n = 40.


Phenology: Flowering spring.
Habitat: Sandy or rocky washes, desert flats
Elevation: 100–700 m

Distribution

V20-1254-distribution-map.gif

Ariz., Calif., Nev., Mexico (Sonora).

Discussion

Senecio mohavensis is similar to S. flavus (Decaisne) Schultz-Bipontinus of the Mediterranean region and southwest Asia, which raises phytogeographic questions (cf. A. Liston et al. 1989; Liston and J. W. Kadereit 1995; M. Coleman et al. 2001). The last cited study showed that a previously recognized variety of S. flavus is more closely related to S. mohavensis than to S. flavus and a new combination was made: S. mohavensis subsp. brevifolius (Kadereit) M. Coleman.

Lower Taxa

None.