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heath groundsel, wood groundsel, woodland groundsel, woodland ragwort

butterweed, rayless groundsel, rayless ragwort

Habit Annuals, (15–)30–80+ cm (taproots fibrous-rooted). Perennials (biennials?), 30–90 cm (caudices buttonlike, roots unbranched, fleshy-fibrous).
Herbage

puberulent (hairs abundant, curly).

loosely and sparsely arachnose to finely tomentose, unevenly glabrescent.

Stems

single.

single.

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).

progressively reduced distally; petiolate;

blades ovate or oblanceolate to oblong, 7–20 × 2–3 cm, bases broadly to narrowly tapered, margins repand-denticulate or sublaciniate to subentire (mid and distal leaves sessile, smaller, weakly clasping).

Ray florets

0 or 1–8+;

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

0 or 1–2;

corolla laminae 4–7 mm.

Phyllaries

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

± 8 or ± 13, 4–8 mm, tips green or black.

Calyculi

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

0 or of 1–3+ oblong to linear bractlets (seldom more than 1.5 mm).

Heads

12–24 in corymbiform arrays.

(6–)15–30+ in corymbiform arrays.

Cypselae

hairy (especially on angles).

glabrous.

2n

= 40.

= 40.

Senecio sylvaticus

Senecio aronicoides

Phenology Flowering late spring–summer (northern areas of cool, climate); winter (southern areas). Flowering spring–early summer.
Habitat Mildly disturbed woodlands, open, sandy sites Dry or drying sites in open woodlands, upper foothills and montane forests
Elevation 100–300 m (300–1000 ft) 800–2500 m (2600–8200 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
CA; OR
[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. 556.
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. 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. sylvaticus, S. taraxacoides, S. triangularis, S. viscosus, S. vulgaris, S. warnockii, S. wootonii
Synonyms S. leptolepis, S. rawsonianus
Name authority Linnaeus: Sp. Pl. 2: 868. (1753) de Candolle: in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 6: 426. (1838)
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