Senecio triangularis
Senecio eremophilus
arrow-leaf groundsel, arrow-leaf ragwort, arrowleaf butterweed, groundsel
cut-leaf groundsel, desert ragwort, dryland ragwort, Elmer's butterweed
glabrous or sparsely floccose-tomentose when young.
glabrous or glabrate.
single or loosely clustered.
single or loosely clustered.
evenly distributed; petiolate;
blades narrowly triangular, (3–)4–10+ × 2–6 cm, bases usually ± truncate, sometimes tapered, margins usually dentate, rarely subentire (distal leaves subsessile, smaller).
± evenly distributed (proximal often withering before flowering); petiolate or sessile;
blades ovate or lanceolate to narrowly lanceolate, (3–)6–12(–20) × (1–)1.5–5(–7) cm, bases tapered, margins usually pinnate to lacerate, sometimes dentate.
± 8;
corolla laminae 9–15 mm.
± 8;
corolla laminae 5–10 mm.
(± 8) ± 13 (± 21), 6–10 mm, tips usually green, rarely black.
(± 8) ± 13, 3–8+ mm, tips green or black.
of 2–6 bractlets (rarely more than 2 mm).
of 3–5+ (prominent or inconspicuous) bractlets (lengths to 3/4 phyllaries).
10–30(–60) in corymbiform to subracemiform arrays.
10–60+ in compound corymbiform arrays.
glabrous.
usually glabrous, sometimes hirtellous.
= 40, 80.
= 38, 40, 44.
Senecio triangularis
Senecio eremophilus
Plants of Senecio triangularis with narrow, subentire leaves that taper to the petioles are occasionally encountered in acid bogs in Oregon and Washington and less frequently elsewhere. They are regarded as edaphic variants; they have been recognized as var. angustifolius.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Varieties 3 (3 in the flora).
Varieties of Senecio eremophilus are distinguished by head size and distribution. Varieties eremophilus and macdougalii are notably different; var. kingii is intermediate in both morphology and distribution.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Calyculi: bractlets prominent (lengths of at least some to about 3/4 phyllaries); involucres 7–10 mm diam.; phyllaries 6–8 mm, tips green or weakly, if at all, black | var. eremophilus |
1. Calyculi: bractlets conspicuous or inconspicuous (lengths rarely to 1/2 phyllaries); involucres 5–8 mm diam.; phyllaries 3–6 mm, tips usually black | → 2 |
2. Calyculi: bractlets conspicuous (lengths to 1/2 phyllaries); involucres (5–)6–8 diam.; phyllaries ± 13, (4–)5–6 mm | var. kingii |
2. Calyculi: bractlets inconspicuous; involucres 4–5(–6) mm diam.; phyllaries ± 8 or ± 13, 3–5 mm | var. macdougalii |
BC
CA
OR
WA
Flora NW
PNW Herbaria
SW CO Wildflowers
WildflowerSearch
iNaturalist
USDA Plants Database
