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

heath groundsel, wood groundsel, woodland groundsel, woodland ragwort

Habit Perennials, (15–)20–50(–70) cm (rhizomes branched, ± woody). Annuals, (15–)30–80+ cm (taproots fibrous-rooted).
Herbage

glabrous.

puberulent (hairs abundant, curly).

Stems

1–(2–4).

single.

Leaves

(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).

evenly distributed; petiolate;

blades obovate to oblong, 3–7(–12) × 1–3(–4) cm, usually 1–2-pinnate, bases tapered, ultimate margins dentate (distal leaves similar, clasping, bractlike).

Ray florets

± 8 or ± 13;

corolla laminae 5–12 mm.

0 or 1–8+;

corolla laminae usually 1–2+ mm (barely surpassing phyllaries).

Phyllaries

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

± 13 (± 21), 4–7+ mm, tips greenish or minutely black.

Calyculi

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

0 or of 1–5+ linear to filiform bractlets.

Heads

(1–)4–12 in corymbiform arrays.

12–24 in corymbiform arrays.

Cypselae

glabrous.

hairy (especially on angles).

2n

= 40.

= 40.

Senecio crassulus

Senecio sylvaticus

Phenology Flowering summer. Flowering late spring–summer (northern areas of cool, climate); winter (southern areas).
Habitat Moist to drying hillsides, meadows, other open places in forest associations Mildly disturbed woodlands, open, sandy sites
Elevation 2200–3700 m (7200–12100 ft) 100–300 m (300–1000 ft)
Distribution
from FNA
CO; ID; MT; NM; NV; OR; SD; UT; WY
[WildflowerSearch map]
[BONAP county map]
from FNA
CA; LA; MA; MI; NJ; OH; OR; PA; WA; WI; BC; NB; NF; NS; PE; QC; Eurasia [Introduced in North America]
[WildflowerSearch map]
[BONAP county map]
Discussion

Senecio sylvaticus is a Eurasian weed that favors cool, wet climates. It is well established in coastal areas of the Pacific Coast and in parts of Newfoundland and Quebec; elsewhere in the flora, it appears to be sporadic.

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

Source FNA vol. 20, p. 551. FNA vol. 20, p. 563.
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. 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
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. spartioides, S. sphaerocephalus, S. spribillei, S. squalidus, S. taraxacoides, S. triangularis, S. viscosus, S. vulgaris, S. warnockii, S. wootonii
Synonyms S. lapathifolius, S. semiamplexicaulis
Name authority A. Gray: Proc. Amer. Acad. Arts 19: 54. (1883) Linnaeus: Sp. Pl. 2: 868. (1753)
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