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Senecio neowebsteri

Olympic Mountain ragwort

alkali marsh groundsel, alkali-marsh butterweed, alkali-marsh ragwort, water groundsel, water ragwort

Habit Perennials, 7–15(–20+) cm (rhizomes fibrous-rooted). Perennials (biennials?), 40–100(–200) cm (caudices foreshortened, roots fleshy-fibrous).
Herbage

(sometimes purplish-tinged) floccose-tomentose, unevenly glabrescent.

(often sea-green, usually glaucous) glabrous.

Stems

single or loosely clustered (erect or arching).

single or 2–4 loosely clustered.

Leaves

mostly cauline;

petiolate (petioles about equaling blades);

blades lanceolate or oblanceolate to ovate, (2–)4–8+ × 1.5–3 cm, bases tapered, margins denticulate (distal leaves smaller, lanceolate or linear-lanceolate, bractlike).

progressively reduced distally; ± petiolate;

blades elliptic to oblanceolate, 5–20+ × (1–)2–10 cm, bases tapered, margins denticulate or entire (mid and distal leaves sessile, bractlike).

Ray florets

± 13;

corolla laminae ± 15 mm.

(0) ca. 5;

corolla laminae 3–5 mm.

Phyllaries

usually ± 21, sometimes ± 13, (8–)10–15 mm, tips usually greenish (often sparsely hairy).

± 8 or ± 13, 5–8 mm, tips frequently black.

Calyculi

of 4–8 lanceolate to lance-linear bractlets (lengths mostly less than 1/2 phyllaries).

of 2–4+ bractlets (less than 2 mm).

Heads

nodding, 1(–2).

20–40(–80+) in compound corymbiform arrays.

Cypselae

glabrous.

glabrous.

2n

= 40.

= 40.

Senecio neowebsteri

Senecio hydrophilus

Phenology Flowering late summer–early fall. Flowering spring–early summer.
Habitat High talus slopes Marshes, swampy places, standing water, alkaline sites
Elevation 2200–2600 m (7200–8500 ft) (0–)200–2500 m ((0–)700–8200 ft)
Distribution
from FNA
WA
[WildflowerSearch map]
[BONAP county map]
from FNA
CA; CO; ID; MT; NV; OR; SD; UT; WA; WY; BC
[WildflowerSearch map]
[BONAP county map]
Discussion

Of conservation concern.

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

Source FNA vol. 20, p. 553. FNA vol. 20, p. 557.
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. 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. 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. websteri S. hydrophilus var. pacificus
Name authority S. F. Blake: Leafl. W. Bot. 8: 143. (1957) Nuttall: Trans. Amer. Philos. Soc., n. s. 7: 411. (1841)
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