Cirsium andrewsii |
Cirsium inamoenum |
|||||
---|---|---|---|---|---|---|
Franciscan thistle |
Davis' thistle, Greene's thistle, intermountain thistle, Jackson hole thistle |
|||||
Habit | Biennials (or short–lived monocarpic perennials), 60–200 cm; taprooted. | Biennials or monocarpic perennials, 20–100 cm; deeply taprooted. | ||||
Stems | several, erect to spreading, thinly arachnoid, soon glabrous; branches ± fleshy, usually much branched proximally, spreading to ascending. |
1–several, erect, thinly to densely gray-tomentose with fine, non-septate trichomes; branches 0–many, ascending. |
||||
Leaves | blades ± elliptic, 30–75 × 10–20 cm, shallowly to deeply pinnatifid, lobes oblong to ovate, unlobed or with several prominent secondary lobes or large teeth, obtuse to acute, main spines 2–7 mm, abaxial gray arachnoid-tomentose, adaxial faces thinly arachnoid, glabrate; basal often present at flowering, spiny winged-petiolate; principal cauline sessile, bases clasping with broad, spiny-margined auricles, reduced distally, spinier than proximal; distal much reduced, spines 7–20 mm. |
blades oblanceolate or elliptic, 10–35 × 1–7 cm, unlobed and spinulose to dentate or deeply pinnatifid, usually 5–8 pairs of lobes, well separated, linear to lance-triangular, spinulose to few toothed or lobed, main spines 2–7 mm, abaxial faces densely gray-tomentose or sometimes ± glabrate, adaxial gray to ± green, thinly tomentose or ± glabrate; basal sometimes present at flowering, narrowly winged-petiolate; principal cauline well distributed, gradually reduced, sometimes spinier than basal; proximal winged-petiolate, mid sessile, bases spiny-winged, decurrent 1–3 cm; distal becoming bractlike, often unlobed or less deeply divided than proximal. |
||||
Peduncles | 0–7 cm. |
0–25 cm. |
||||
Involucres | ovoid to hemispheric or campanulate, 1.5–3 × 1.5–5 cm, sparsely to densely arachnoid, finely short-ciliate. |
ovoid or hemispheric to campanulate, 2–3 × 1.5–5 cm, glabrous or loosely floccose to densely arachnoid. |
||||
Corollas | dark reddish purple, 17–24 mm, tubes 8–11 mm, throats 3.5–6 mm, lobes 5–7 mm; style tips 3–4 mm. |
dull white or faintly lavender-tinged to bright pink-purple, 19–31 mm, tubes 7–13 mm, throats 6.5–9.5 mm, lobes 4–8 mm; style tips 3.5–7 mm. |
||||
Phyllaries | in ca. 6 series, dark green or brown or with stramineous margins and a darker central zone, imbricate, linear-lanceolate (outer) to linear (inner), abaxial faces without glutinous ridge; outer and mid bodies appressed, spiny-ciliate, apices long-spreading to ascending long-acuminate, spines straight, stout, 5–15 mm; apices of inner straight or twisted, long, entire, flat or spine-tipped. |
in 6–10 series, strongly imbricate or sometimes subequal, greenish to brown, ovate to linear-lanceolate (outer) to linear (inner), entire, abaxial faces with narrow or scarcely developed glutinous ridge; outer and mid appressed or apices ascending to spreading, linear, bodies entire, spines ascending to abruptly spreading, usually fine, 2–6 mm; apices of inner narrow, spine-tipped or spineless. |
||||
Heads | several–many, in congested corymbiform arrays. |
1–many, in open corymbiform arrays or crowded near stem tips. |
||||
Cypselae | dark brown, 4–5 mm, apical collars narrow; pappi 15 mm. |
brown, 5–8 mm, apical collars not differentiated; pappi 12–25 mm. |
||||
2n | = 32. |
= 32, 34, 36. |
||||
Cirsium andrewsii |
Cirsium inamoenum |
|||||
Phenology | Flowering spring–summer (May–Sep). | |||||
Habitat | Headlands, ravines, seeps near coast, sometimes on serpentine | |||||
Elevation | 0–100 m (0–300 ft) | |||||
Distribution |
CA
|
CA; ID; NV; OR; UT; WA; WY
|
||||
Discussion | Of conservation concern. Cirsium andrewsii occurs along the coast of north-central California from San Mateo to Marin counties. It reportedly hybridizes with C. quercetorum (F. Petrak 1917; J. T. Howell 1960b). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Varieties 2 (2 in the flora). Cirsium inamoenum is a variable complex across the northern Great Basin and adjacent mountains. A. Cronquist (1994) treated this complex as a single species under the name C. subniveum without infraspecific taxa and including taxa that formerly had been assigned to C. utahense (e.g., J. T. Howell 1960b). Some populations consist of small-headed, white-flowered plants with strong involucres and short, appressed phyllaries. Others have larger heads, white or lavender to pink-purple corollas, and phyllaries with longer, ascending to spreading tips. My treatment of this complex as C. inamoenum is similarly inclusive as was Cronquist’s treatment of C. subniveum, except that I believe C. humboldtense, which Cronquist included, is probably a derivative of hybridization between C. subniveum and C. eatonii var. peckii. I have observed such hybrids on the slopes of Steens Mountain in Harney County, Oregon, and the type of C. humboldtense closely resembles some of the introgressants. I have examined several other specimens that are likely the products of hybridization of C. inamoenum with other varieties of C. eatonii. I have chosen to recognize racial differentiation within Cirsium inamoenum at the rank of variety. The main difference between Cirsium inamoenum var. inamoenum and var. davisii is corolla color. Unfortunately this feature is sometimes difficult to determine on herbarium specimens, and many collectors fail to include corolla color on specimen labels. Some geographic overlap occurs between var. davisii, which has a distribution centered in northeastern Utah, southeastern Idaho, and adjacent southwestern Wyoming, and the more widespread var. inamoenum. Plants of northeastern Oregon, southeastern Washington, and adjacent western Idaho often have large heads and densely tomentose foliage. These were named Cirsium wallowense by Peck. Similar plants occur sporadically in other portions of the range of Cirsium inamoenum var. inamoenum and I chose not to recognize these northwestern populations as a third variety. Additional study might clarify the relationships of these plants. Some specimens of Cirsium inamoenum in central Nevada and Utah approach C. neomexicanum. It seems likely that these species have interacted in the past. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
||||
Key |
|
|||||
Source | FNA vol. 19, p. 141. | FNA vol. 19, p. 134. | ||||
Parent taxa | ||||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | Cnicus andrewsii | Carduus inamoenus | ||||
Name authority | (A. Gray) Jepson: Fl. W. Calif., 506. (1901) | (Greene) D. J. Keil: Sida 21: 214. (2004) | ||||
Web links |
|