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

cut-leaf groundsel, desert ragwort, dryland ragwort, Elmer's butterweed

Habit Perennials (possibly biennials), (10–)20–70 cm (caudices buttonlike, roots fleshy-fibrous). Perennials, (20–)40–80(–140) cm (caudices branched, fibrous-rooted).
Herbage

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

glabrous or glabrate.

Stems

single.

single or loosely clustered.

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).

± 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.

Ray florets

usually ± 8 or ± 13, sometimes 0;

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

± 8;

corolla laminae 5–10 mm.

Phyllaries

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

(± 8) ± 13, 3–8+ mm, tips green or black.

Calyculi

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

of 3–5+ (prominent or inconspicuous) bractlets (lengths to 3/4 phyllaries).

Heads

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

10–60+ in compound corymbiform arrays.

Cypselae

usually glabrous, sometimes hirtellous (mostly on angles).

usually glabrous, sometimes hirtellous.

2n

= 40, 80.

= 38, 40, 44.

Senecio integerrimus

Senecio eremophilus

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
AK; AZ; CO; MT; ND; NM; SD; UT; WY; AB; BC; MB; NT; ON; SK; w North America; Mostly n North America
[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.)

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.)

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
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
Source FNA vol. 20, p. 556. FNA vol. 20, p. 565.
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. crassulus, S. elegans, S. elmeri, 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
S. eremophilus var. eremophilus, S. eremophilus var. kingii, S. eremophilus var. macdougalii
Name authority Nuttall: Gen. N. Amer. Pl. 2: 165. (1818) Richardson: in J. Franklin et al., Narr. Journey Polar Sea, 759. (1823)
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