Senecio spartioides
Senecio serra
broom groundsel, broom senecio, broom-like ragwort, grass-leaf ragwort, many-head groundsel
butterweed groundsel, sawtooth groundsel, serrated ragwort, tall butterweed, tall ragwort
usually glabrous, sometimes sparsely, unevenly hairy.
glabrous or lightly floccose-tomentose proximally when young.
usually multiple (branching and arching upward).
single or loosely clustered.
evenly distributed (proximal often smaller);
sessile or obscurely petiolate;
blades narrowly linear to filiform (or parted into linear-filiform lobes), 5–10 cm × 1–6 mm, bases ± linear, ultimate margins entire.
evenly distributed (proximal often withering before flowering); petiolate or subsessile;
blades lanceolate or narrowly lanceolate to sublinear, 5–15(–20+) × (1–)1.5–4 cm, bases tapered, margins dentate to subentire (distal leaves smaller, bractlike).
± 5 (± 13);
corolla laminae 8–12 mm.
± 5 or ± 8;
corolla laminae 5–10 mm.
usually ± 8, sometimes ± 13, (5–)6–9(–10) mm, tips green or minutely black.
± 8 or ca. 13, 4–9 mm, tips usually green, sometimes black.
0 or of 1–3+ (minute, inconspicuous) bractlets.
of 2–6 linear to filiform bractlets (0.5–5 mm).
10–20(–60) in compound corymbiform arrays (involucres cylindric or narrowly campanulate, 3–6 mm diam.).
30–90+ in corymbiform to subpaniculiform arrays.
usually hirtellous, sometimes glabrous.
glabrous or glabrate.
= 40.
= 40.
Senecio spartioides
Senecio serra
Plants with the leaves parted into lobes that are seldom more than 1 mm wide have been recognized as Senecio spartioides var. multicapitatus (or as S. multicapitatus); expression of the character is inconsistent throughout the range and recognition of the two entities is all but impossible to maintain.
Senecio spartioides apparently hybridizes with S. eremophilus in Garfield County, Utah, and perhaps elsewhere (cf., Holmgren, Reveal, and LaFrance 3463, BRY, KSC, NY). The name Senecio toiyabensis rests upon materials that suggest introgression with S. fremontii. Some specimens usually referred to 41. S. pattersonensis suggest introgression with S. spartioides.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Varieties 2 (2 in the flora).
Varieties of Senecio serra are distinguished by head size and distribution.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Heads 40–90+; phyllaries ± 8, 4–6 mm; ray florets ± 5, corolla laminae 5–7 mm; disc florets 10–20 | var. serra |
1. Heads (12–)30–50; phyllaries ± 13, 7–9 mm; ray florets ± 8, corolla laminae 7–10 mm; disc florets 20–40+ | var. admirabilis |
CA
SW CO Wildflowers
WildflowerSearch
iNaturalist
USDA Plants Database
OR
WA
Flora NW
PNW Herbaria
