Flora of North America species comparison

The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

Senecio cannabifolius

Senecio riddellii

Aleutian ragwort

Riddell's groundsel, Riddell's ragwort
Habit Perennials, (50–)100–150+ cm (rhizomes fibrous-rooted). Subshrubs, 30–100 cm (taproots forming woody crowns).
Herbage

unevenly tomentose, glabrescent, except persistently hairy on abaxial faces of leaves.

glabrous.
Stems

single.

usually multiple (branching upward).
Leaves

± evenly distributed (basal and proximal withering before flowering); mostly petiolate (proximal);

blades oblong or ovate to oblong-lanceolate (pinnately or subpalmately parted, primary lobes 3–6+, lanceolate to lance-linear, 3–8+ cm), 10–20+ × 8–15+ cm, bases ± tapered, ultimate margins serrate (distal leaves similar, sessile, smaller).

± evenly distributed (proximal often withering before flowering, pendulous);

sessile or obscurely petiolate;

blades linear-filiform (or irregularly pinnately divided into linear-filiform lobes), blades or lobes 4–9 cm × 1–5 mm, bases ± linear, ultimate margins entire.
Ray florets

± 5;

corolla laminae ca. 10 mm.

± 8;

corolla laminae (often falling early) 8–10 mm.
Phyllaries

± 13, 4–6 mm, tips green.

± 13, 7–10(–12+) mm, tips green.
Calyculi

0 or of 1–5+ subulate bractlets (lengths about 1/3 phyllaries).

usually of 3–8+ lance-linear to filiform bractlets (lengths 1/10–1/3 phyllaries).
Heads

20–50 in corymbiform arrays.

5–20+ in close, corymbiform arrays (involucres campanulate, 7–10 mm diam.).
Cypselae

glabrous.

hirtellous.
2n

= 40.

= 40.

Senecio cannabifolius

Senecio riddellii
Phenology Flowering summer. Flowering mostly mid summer–fall, occasionally spring.
Habitat Open meadows and slopes Sandy or rocky open sites, especially drying, open, flood plains
Elevation 0–100 m (0–300 ft) 600–2500 m (2000–8200 ft)
Distribution
from FNA
AK; Eurasia
[BONAP county map]
from FNA
AZ; CO; KS; NE; NM; OK; SD; TX; WY
[WildflowerSearch map]
[BONAP county map]
Discussion

Senecio cannabifolius barely enters the flora from far-eastern Asia. Infraspecific taxa are recognized within S. cannabifolius in some floras of Asiatic regions; our plants are referable to var. cannabifolius.

Senecio cannabifolius has been treated in Jacobaea by E. Wiebe (2000); see discussion under 53. S. jacobaea.

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

Senecio riddellii intergrades morphologically with S. spartioides. Typically, the former has larger heads with campanulate involucres 7–10 mm diam.; the latter has cylindric involucres rarely more than 6 mm diam.

Senecio riddellii is poisonous to livestock. It is now locally scarce because of efforts to eradicate it.

(Discussion copyrighted by Flora of North America; reprinted with permission.)
Source FNA vol. 20, p. 569. FNA vol. 20, p. 560.
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. 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
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. 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 Jacobaea cannabifolia, S. palmatus S. filifolius var. fremontii, S. riddellii var. parksii, S. spartioides var. fremontii, S. spartioides var. parksii, S. spartioides var. riddellii
Name authority Lessing: Linnaea 6: 242. (1831) Torrey & A. Gray: Fl. N. Amer. 2: 444. (1843)
Web links 
Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).



Type/paste one or more Latin names into the boxes above; matching taxa will show up below the box as you type. You can use the up/down arrow keys to move through the list.

(If the plant you're looking for doesn't show up in the auto-complete list, that means it either isn't described in Flora of North America yet, or it's listed under a synonym. And please note that Flora of North America is still missing several plant families, including Apiaceae, Boraginaceae, and Polemoniaceae.)

Choose a data source: Flora of North America

The species comparison tool is brought to you by:
Northwest Wildflowers