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

broom groundsel, broom senecio, broom-like ragwort, grass-leaf ragwort, many-head groundsel

Habit Perennials (possibly biennials), (10–)20–70 cm (caudices buttonlike, roots fleshy-fibrous). Subshrubs, 20–120+ cm (taproots forming woody crowns).
Herbage

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

usually glabrous, sometimes sparsely, unevenly hairy.

Stems

single.

usually multiple (branching and arching upward).

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 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.

Ray florets

usually ± 8 or ± 13, sometimes 0;

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

± 5 (± 13);

corolla laminae 8–12 mm.

Phyllaries

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

usually ± 8, sometimes ± 13, (5–)6–9(–10) mm, tips green or minutely black.

Calyculi

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

0 or of 1–3+ (minute, inconspicuous) bractlets.

Heads

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

10–20(–60) in compound corymbiform arrays (involucres cylindric or narrowly campanulate, 3–6 mm diam.).

Cypselae

usually glabrous, sometimes hirtellous (mostly on angles).

usually hirtellous, sometimes glabrous.

2n

= 40, 80.

= 40.

Senecio integerrimus

Senecio spartioides

Phenology Flowering summer–fall.
Habitat Open, dry disturbed sites, especially stream banks and hillsides
Elevation 1000–3500 m (3300–11500 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
AZ; CA; CO; NE; NM; NV; SD; TX; 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.)

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.)

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. 559.
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. 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. 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. andersonii, S. incurvus, S. multicapitatus, S. serra var. sanctus, S. spartioides var. granularis, S. toiyabensis
Name authority Nuttall: Gen. N. Amer. Pl. 2: 165. (1818) Torrey & A. Gray: Fl. N. Amer. 2: 438. (1843)
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