The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

Douglas' groundsel, Mono groundsel, shrubby butterweed, shrubby ragwort, threadleaf groundsel, threadleaf ragwort

Photo is of parent taxon

Mono groundsel, smooth threadleaf ragwort

Habit Subshrubs or shrubs, (30–)40–120+ cm (taproots forming woody crowns).
Herbage

glabrous or ± lanate-tomentose.

glabrate or glabrous.

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).

Involucres

campanulate.

Ray florets

usually ± 8 or ± 13, sometimes ± 21;

corolla laminae 10–15(–20) mm (mostly yellow, sometimes ochroleucous).

Phyllaries

± 13 or ± 21+, 5–10(–12) mm, tips green or minutely black.

(± 13) ± 21, 7–10+ mm.

Calyculi

usually of 3–5+ bractlets (lengths often to 1/2+ phyllaries), sometimes 0.

bractlets well developed (lengths, at least some, 1/2 phyllaries).

Heads

(1–)3–10(–20+) in corymbiform or subcorymbiform clusters, often gathered in larger, showy arrays (involucres campanulate or cylindric).

Cypselae

hairy.

2n

= 40.

Senecio flaccidus

Senecio flaccidus var. monoensis

Phenology Flowering mostly summer–fall, less commonly spring.
Habitat Open, rocky or sandy sites, especially desert basins and washes
Elevation 600–2000 m (2000–6600 ft)
Distribution
from FNA
AZ; CA; CO; KS; NM; NV; OK; TX; UT; Mexico
[WildflowerSearch map]
[BONAP county map]
from FNA
AZ; CA; NM; NV; TX; UT; Mexico (Baja California)
[BONAP county map]
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.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Senecio flaccidus var. monoensis intergrades with var. douglasii and with var. flaccidus in areas of range overlap.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

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
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
var. douglasii
2. Plants glabrate or glabrous; California deserts e of crest of Sierra Nevada and eastward
var. monoensis
Source FNA vol. 20, p. 558. FNA vol. 20, p. 559.
Parent taxa Asteraceae > tribe Senecioneae > Senecio Asteraceae > tribe Senecioneae > Senecio > Senecio flaccidus
Sibling taxa
S. actinella, S. amplectens, S. ampullaceus, S. aphanactis, S. arizonicus, S. aronicoides, S. astephanus, S. atratus, S. bigelovii, S. blochmaniae, S. californicus, S. cannabifolius, S. clarkianus, S. crassulus, S. elegans, S. elmeri, S. eremophilus, S. ertterae, S. erucifolius, S. fremontii, S. hydrophiloides, S. hydrophilus, S. integerrimus, S. jacobaea, S. lemmonii, S. lugens, S. lyonii, S. megacephalus, S. mohavensis, S. multidentatus, S. neowebsteri, S. parryi, S. pattersonensis, S. pseudoarnica, S. pudicus, S. quaylei, S. rapifolius, S. riddellii, S. sacramentanus, S. scorzonella, S. serra, S. sheldonensis, S. soldanella, S. spartioides, S. sphaerocephalus, S. spribillei, S. squalidus, S. sylvaticus, S. taraxacoides, S. triangularis, S. viscosus, S. vulgaris, S. warnockii, S. wootonii
S. flaccidus var. douglasii, S. flaccidus var. flaccidus
Subordinate taxa
S. flaccidus var. douglasii, S. flaccidus var. flaccidus, S. flaccidus var. monoensis
Synonyms S. monoensis, S. filicifolius, S. lathyroides, S. pectinatus
Name authority Lessing: Linnaea 5: 161. (1830) (Greene) B. L. Turner & T. M. Barkley: Phytologia 69: 54. (1990)
Web links