Senecio integerrimus |
Senecio triangularis |
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lambstongue ragwort, western groundsel |
arrowleaf groundsel |
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Habit | Herbs perennial or biennial, (1)2–7 dm; caudices button-like, with fleshy, fibrous, unbranched roots. | Herbs perennial, (2)5–12(20) dm; caudices branching, woody, rhizomatous. |
Stems | 1, loosely arachnoid-tomentose, or villous, glabrate with age. |
1 or 2–4 and loosely clustered, glabrous or sparsely pubescent. |
Leaves | mostly basal; cauline progressively reduced distally; ± petiolate; basal and lower cauline elliptic, lanceolate, linear, oblanceolate, rounded-deltate, rarely suborbiculate, bases tapered or truncate to cordate; margins entire or dentate; distal becoming sessile and bract-like. |
basal present at flowering; cauline ± evenly distributed along stems, gradually reduced distally, narrowly to widely triangular, bases tapered to truncate or cordate; margins dentate, rarely subentire; surfaces sparsely tomentose to nearly glabrous; proximal petiolate; distal sessile. |
Inflorescences | corymb-like arrays; bracts 0 or inconspicuous. |
corymb- or ± raceme-like arrays; bracts conspicuous. |
Involucres | urn-shaped. |
cylindric to narrowly campanulate. |
Ray florets | 5, rarely 0; rays 6–15(20) mm, yellow or white to pale yellow. |
~8; rays 9–15 mm. |
Disc florets | 35–45. |
35–45. |
Phyllaries | (8)13 or 21; tips usually black, sometimes green. |
(8)13(21), 6–10 mm; tips green, rarely black. |
Calyculi | 1–5+, inconspicuous, usually < 2 mm. |
2–6 bractlets, inconspicuous, rarely > 2 mm. |
Fruits | 2.5–3 mm, usually glabrous, sometimes hairy along ribs. |
2.5–3.5 mm, glabrous. |
Heads | 6–15(30+). |
10–30(60). |
2n | =40, 80. |
=40, 80. |
Senecio integerrimus |
Senecio triangularis |
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Distribution | ||
Discussion | Western North America. 5 varieties; 3 varieties treated in Flora. |
Open areas, rocky streambanks, wet meadows, bogs, damp places in coniferous forests. Flowering May–Sep. 0–2800 m. BR, BW, Casc, CR, ECas, Est, Lava, Sisk, WV. CA, ID, NV, WA; north to AK, northeast to MT, east to WY, southeast to NM. Native. Some plants with narrow, subentire leaves that taper to the petioles have been found in acidic bogs in Washington and Oregon. A few authors recognize these as variety angustifolia. However, this author has observed several specimens (specifically indicated as being collected in bogs) that had both narrower leaves and the wider leaves more typical of variety triangularis on the same plant. |
Source | Flora of Oregon, volume 2, page 339 Debra Trock |
Flora of Oregon, volume 2, page 341 Debra Trock |
Sibling taxa | ||
Subordinate taxa | ||
Synonyms | Senecio gibbonsii, Senecio triangularis var. angustifolius, Senecio triangularis var. triangularis | |
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