Cirsium andersonii |
Cirsium hookerianum |
|
---|---|---|
Anderson's thistle, rose thistle |
Hooker's thistle, white thistle |
|
Habit | Perennials (but often appearing biennial), (15–)40–70(–100) cm; rootstocks producing erect, taprooted caudices and rosettes. | Biennials or monocarpic (sometimes polycarpic?) perennials, 20–150 cm; taprooted. |
Stems | usually 1, erect, subglabrous to puberulent and/or tomentose; branches 0–several, stiffly ascending. |
usually 1 and erect, less commonly several and ascending, simple to sparingly short-branched in distal 1/2, variably villous with jointed trichomes, and/or finely arachnoid, or ± glabrate; branches on distal stems 0–many, short, ascending. |
Leaves | blades ± elliptic, 8–35 × 4–8 cm, divided about halfway to midveins, lobes spreading, triangular, coarsely dentate or with a few broad lobes, obtuse to acute, main spines 1–5 mm, abaxial faces green or gray, thinly tomentose, adaxial green and glabrous to sparingly pilose; basal often present at flowering, spiny winged-petiolate; main cauline reduced distally, bases clasping; distal much reduced, linear-oblong, usually less deeply lobed and often spinier than proximal. |
blades linear-oblong to elliptic, 5–25 × 1–8 cm, subentire to coarsely dentate or deeply pinnatifid, lobes lance-oblong to broadly triangular, spinulose to spiny-dentate or shallowly lobed, main spines 2–10 mm, abaxial faces usually ± densely gray- or white-tomentose with felted arachnoid trichomes, ± villous to tomentose along major veins with septate trichomes, sometimes glabrous or glabrate, adaxial ± green, glabrous to thinly arachnoid, often ± villous or tomentose with septate trichomes; basal often present at flowering, spiny winged-petiolate or sessile; principal cauline well distributed, proximally winged-petiolate, distally sessile, gradually reduced, bases sometimes short-decurrent; distal ± reduced, often narrower than proximal, sometimes with non-pigmented bases, sometimes pectinately spiny. |
Peduncles | 0–20 cm. |
0–8+ cm. |
Involucres | broadly cylindric to narrowly campanulate, 3–5 × 2–4 cm, loosely arachnoid or ± glabrous, finely short-ciliate. |
(green or often purplish), broadly ovoid, 2–3.3 × 1.5–4 cm, loosely to densely villous with septate trichomes to tomentose and/or arachnoid. |
Corollas | red to reddish purple, 30–45 mm, tubes 10–20 mm, throats 10–16 mm, lobes 9–11 mm; style tips 3.5–5 mm. |
white, ochroleucous, or occasionally pink, 20–28 mm, tubes 10–13 mm, throats 6.5–9 mm, lobes 5–7 mm; style tips 3–5.5 mm. |
Phyllaries | in 6–8 series, imbricate, outer green, inner purple to red, linear-lanceolate (outer) to linear (inner), abaxial faces without glutinous ridge; outer and mid bodies short, appressed, entire or spinulose-ciliate, apices long-spreading to ascending, entire or spinulose-ciliate or rarely with expanded, fringed appendages, spines straight, weak, 1–3 mm; apices of inner red to purple, straight or rarely twisted, long, flat, entire. |
in 4–8 series, imbricate to subequal, bases short-appressed, entire, abaxial faces with or without narrow glutinous ridge, apices stiffly spreading to ascending, linear, long, plane, spines straight, slender, 3–5 mm; apices of inner flexuous, sometimes expanded and erose. |
Heads | 1–6, borne singly or in corymbiform, racemiform, or spiciform arrays. |
1–many, borne singly or crowded in spiciform, racemiform, subcapitate, or sometimes more openly branched corymbiform arrays. |
Cypselae | brown, 6–7 mm, apical collars narrow; pappi 25–40 mm. |
dark brown, 5–6.5 mm, apical collars not differentiated; pappi 18–22 mm. |
2n | = 32, 64. |
= 34. |
Cirsium andersonii |
Cirsium hookerianum |
|
Phenology | Flowering summer (Jul–Sep). | Flowering summer (Jun–Sep). |
Habitat | Moist to dry soils, openings in montane woodlands, montaine coniferous forests, aspen groves | Moist soil, grasslands, aspen parkland, forest edges and openings, subalpine, alpine meadows |
Elevation | 1100–2900 m (3600–9500 ft) | 600–2900 m (2000–9500 ft) |
Distribution |
CA; ID; NV
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ID; MT; WA; WY; AB; BC
|
Discussion | Cirsium andersonii grows in the Cascade Range of northern California south through the Sierra Nevada of eastern California and western Nevada. It has been reported from the mountains of southwestern Idaho, but I have not seen specimens from there. Heads of Cirsium andersonii are actively visited by hummingbirds as well as a variety of insects (P. L. Barlow-Irick 2002). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Cirsium hookerianum occurs from the Canadian Coast Ranges of British Columbia east to the northern Cascade Range and the northern Rocky Mountains. The relationship between C. hookerianum, C. kelseyi, which I have tentatively included in C. hookerianum, and C. longistylum needs further investigation. A case could be made for including all three in an expanded concept of C. hookerianum, but more investigation of the variation patterns is needed before this is done. Certainly C. kelseyi is better treated within or as a close ally of C. hookerianum than in C. scariosum (var. scariosum), where R. J. Moore and C. Frankton (1974) synonymized it. Cirsium hookerianum is known to hybridize with C. undulatum. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 19, p. 145. | FNA vol. 19, p. 148. |
Parent taxa | Asteraceae > tribe Cardueae > Cirsium | Asteraceae > tribe Cardueae > Cirsium |
Sibling taxa | ||
Synonyms | Cnicus andersonii | C. kelseyi |
Name authority | (A. Gray) Petrak: Bot. Tiddsskr. 31: 68. (1911) | Nuttall: Trans. Amer. Philos. Soc., n. s. 7: 418. (1841) |
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