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heath groundsel, wood groundsel, woodland groundsel, woodland ragwort

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

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

puberulent (hairs abundant, curly).

glabrous.

Stems

single.

1–(2–4).

Leaves

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).

(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

0 or 1–8+;

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

± 8 or ± 13;

corolla laminae 5–12 mm.

Phyllaries

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

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

Calyculi

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

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

Heads

12–24 in corymbiform arrays.

(1–)4–12 in corymbiform arrays.

Cypselae

hairy (especially on angles).

glabrous.

2n

= 40.

= 40.

Senecio sylvaticus

Senecio crassulus

Phenology Flowering late spring–summer (northern areas of cool, climate); winter (southern areas). Flowering summer.
Habitat Mildly disturbed woodlands, open, sandy sites Moist to drying hillsides, meadows, other open places in forest associations
Elevation 100–300 m (300–1000 ft) 2200–3700 m (7200–12100 ft)
Distribution
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]
from FNA
CO; ID; MT; NM; NV; OR; SD; UT; WY
[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. 563. 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. 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
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
Synonyms S. lapathifolius, S. semiamplexicaulis
Name authority Linnaeus: Sp. Pl. 2: 868. (1753) A. Gray: Proc. Amer. Acad. Arts 19: 54. (1883)
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