Cirsium crassicaule |
Cirsium andersonii |
|
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slough thistle |
Anderson's thistle, rose thistle |
|
Habit | Annuals or biennials, (60–)100–300 cm; taprooted. | Perennials (but often appearing biennial), (15–)40–70(–100) cm; rootstocks producing erect, taprooted caudices and rosettes. |
Stems | usually 1, erect, stout, (hollow, 2–10 cm diam. at base), openly branched distally, thinly arachnoid, villous with jointed trichomes, at least proximally. |
usually 1, erect, subglabrous to puberulent and/or tomentose; branches 0–several, stiffly ascending. |
Leaves | blades elliptic to broadly oblanceolate, 15–70 × 30–150+ cm, flat, pinnatifid 1/2–2/3 distance to midvein, larger usually with broad sinuses, lobes broad, few lobed or dentate, main spines 3–8 mm, abaxial faces gray-tomentose, adaxial thinly arachnoid-tomentose, sometimes midveins with jointed trichomes; basal present or withered at flowering, winged-petiolate; principal cauline sessile, progressively reduced distally, bases clasping or short-decurrent 1–2 cm; distal cauline reduced, becoming bractlike, sometimes spinier than proximal. |
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. |
Peduncles | 0–15 cm. |
0–20 cm. |
Involucres | ovoid to campanulate, 1.5–3 × 1.5–3 cm, ± glabrous. |
broadly cylindric to narrowly campanulate, 3–5 × 2–4 cm, loosely arachnoid or ± glabrous, finely short-ciliate. |
Corollas | pale rose-purple (white), 19–26 mm, tubes 9–12 mm, throats 4–6 mm, lobes 5–9 mm; style tips 3.5–4.5 mm. |
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. |
Phyllaries | in 5–7 series, weakly unequal, dark green to brownish, lanceolate (outer) to linear (inner), abaxial faces without (or with very obscure) glutinous ridge; outer and middle appressed or apices spreading, at least outer irregularly spiny-fringed, finely serrulate, spines slender, 3–5 mm; apices of inner erect, abaxial faces gray-tomentose, ± twisted. |
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. |
Heads | 1–several at branch tips, closely subtended by clustered leafy bracts or not, collectively forming open, corymbiform or paniculiform arrays. |
1–6, borne singly or in corymbiform, racemiform, or spiciform arrays. |
Cypselae | dark brown, 5–5.5 mm, collars narrow, ± stramineous; pappi 15–20 mm. |
brown, 6–7 mm, apical collars narrow; pappi 25–40 mm. |
2n | = 32. |
= 32, 64. |
Cirsium crassicaule |
Cirsium andersonii |
|
Phenology | Flowering spring (Apr–Jun). | Flowering summer (Jul–Sep). |
Habitat | Freshwater marshes, canal banks | Moist to dry soils, openings in montane woodlands, montaine coniferous forests, aspen groves |
Elevation | 5–100 m (0–300 ft) | 1100–2900 m (3600–9500 ft) |
Distribution |
CA |
CA; ID; NV
|
Discussion | Cirsium crassicaule is known only from a few sites in the San Joaquin Valley. Some populations are threatened by habitat modification and development pressures. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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.) |
Source | FNA vol. 19, p. 132. | FNA vol. 19, p. 145. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Carduus crassicaulis | Cnicus andersonii |
Name authority | (Greene) Jepson: Fl. W. Calif., 506. (1901) | (A. Gray) Petrak: Bot. Tiddsskr. 31: 68. (1911) |
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