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lambstongue ragwort, mountain butterweed, one-stem butterweed, tall western groundsel, western groundsel

mountain meadow butterweed, thick-leaf groundsel, thick-leaf ragwort

Habit Perennials (possibly biennials), (10–)20–70 cm (caudices buttonlike, roots fleshy-fibrous). Perennials, (15–)20–50(–70) cm (rhizomes branched, ± woody).
Herbage

arachnose, loosely tomentose, or villous (hairs crisped, jointed), glabrescent.

glabrous.

Stems

single.

1–(2–4).

Leaves

progressively reduced distally; ± petiolate;

blades elliptic, lanceolate, linear, oblanceolate, rounded-deltate, or suborbiculate, 6–25 × 1–6 cm, bases ± tapered or truncate to cordate, margins entire or ± dentate (distal leaves sessile, bractlike).

(thickish-turgid) progressively reduced distally; petiolate;

blades broadly lanceolate to subelliptic, 2.5–15 × 1–5 cm, bases tapered, margins sharply dentate to subentire (some teeth callous; mid leaves sometimes larger than proximal; distal leaves sessile, smaller, often clasping).

Ray florets

usually ± 8 or ± 13, sometimes 0;

corolla laminae 6–15(–20) mm (usually yellow, ochroleucous to white in one variety).

± 8 or ± 13;

corolla laminae 5–12 mm.

Phyllaries

usually ± 13 or ± 21, rarely ± 8, (4–)5–12(–15) mm, tips usually black, sometimes green.

(± 8) ± 13 or ± 21, 5–9 mm, tips black (villous).

Calyculi

of 1–5+ linear to filiform bractlets (seldom more than 2 mm).

of (1–)3–6 linear to filiform bractlets (lengths to 1/3 phyllaries).

Heads

6–20(–40+) in corymbiform arrays (peduncle of terminal head often shorter than others).

(1–)4–12 in corymbiform arrays.

Cypselae

usually glabrous, sometimes hirtellous (mostly on angles).

glabrous.

2n

= 40, 80.

= 40.

Senecio integerrimus

Senecio crassulus

Phenology Flowering summer.
Habitat Moist to drying hillsides, meadows, other open places in forest associations
Elevation 2200–3700 m (7200–12100 ft)
Distribution
from FNA
CA; CO; IA; ID; KS; MN; MT; ND; NE; NM; NV; OR; SD; UT; WA; WY; AB; BC; MB; SK
[WildflowerSearch map]
[BONAP county map]
from FNA
CO; ID; MT; NM; NV; OR; SD; UT; WY
[WildflowerSearch map]
[BONAP county map]
Discussion

Varieties 5 (5 in the flora).

The varieties of Senecio integerrimus are distinguished by morphology and geography.

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

Key
1. Basal leaves with distinct petioles, blades usually ovate to rounded-deltate, sometimes obovate to oblanceolate; ray corollas white or ochroleucous
var. ochroleucus
1. Basal leaves with or without distinct petioles, blades elliptic, lanceolate, oblanceolate, rounded-deltate, sublinear, or suborbiculate; ray corollas yellow (or rays 0)
→ 2
2. Herbage glabrous or glabrate at flowering (except in leaf axils and among heads); phyllaries linear-subulate, tips usually green, minutely (if at all) black
var. integerrimus
2. Herbage usually arachnose, tomentose, or villous at flowering; phyllaries lanceolate to linear-subulate, tips black (if minutely so, then narrowly lanceolate and broader than subulate)
→ 3
3. Basal and proximal leaves oblong or lanceolate to sublinear; heads 3–6(–16+); phyllaries 10–15+ mm
var. scribneri
3. Basal and proximal leaves mostly elliptic to oblanceolate, sometimes elliptic or rounded-deltate to suborbiculate; heads usually 6–15(–30+; if fewer than 6, leaves lanceolate or broader); phyllaries 5–12 mm.
→ 4
4. Plants copiously arachnose, tomentose, or villous at flowering; phyllaries linear-subulate, 8–12 mm, tips minutely, if at all, blackened
var. major
4. Plants copiously to sparsely arachnose, tomentose, or villous at flowering; phyllaries mostly lanceolate (seldom as narrow as linear-subulate), 5–10 mm, tips black
var. exaltatus
Source FNA vol. 20, p. 556. FNA vol. 20, p. 551.
Parent taxa Asteraceae > tribe Senecioneae > Senecio Asteraceae > tribe Senecioneae > Senecio
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. flaccidus, S. fremontii, S. hydrophiloides, S. hydrophilus, 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. 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. elegans, S. elmeri, S. eremophilus, S. ertterae, S. erucifolius, S. flaccidus, 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
Subordinate taxa
S. integerrimus var. exaltatus, S. integerrimus var. integerrimus, S. integerrimus var. major, S. integerrimus var. ochroleucus, S. integerrimus var. scribneri
Synonyms S. lapathifolius, S. semiamplexicaulis
Name authority Nuttall: Gen. N. Amer. Pl. 2: 165. (1818) A. Gray: Proc. Amer. Acad. Arts 19: 54. (1883)
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