Cirsium eatonii var. hesperium

(Eastwood) D. J. Keil

Sida 21: 212. 2004.

Common names: Tall mountain thistle
Endemic
Basionym: Cnicus hesperius Eastwood Bull. Calif. Acad. Sci., ser. 3, 1: 122. 1898
Synonyms: Cirsium hesperium (Eastwood) Petrak
Treatment appears in FNA Volume 19. Treatment on page 152. Mentioned on page 151.

Stems strictly erect, 50–150 cm. Leaf faces glabrous or nearly so or abaxially finely arachnoid-tomentose and/or villous to tomentose with septate trichomes on one or both faces. Heads usually sessile in stiffly erect, tight spiciform arrays, sometimes also sessile in distal leaf-axils. Involucres 2–2.5 cm, tomentose with septate trichomes; outer phyllaries with a few stiff lateral spines; spines of phyllaries slender. Corollas pink or pale to deep purple, 14–21 mm, tubes 4.5–10 mm, throats 3.5–5 mm, lobes 3.5–7 mm. Pappi 8–17 mm.


Phenology: Flowering summer (Jul–Sep).
Habitat: Rocky slopes, subalpine meadows, forest openings
Elevation: 2700–3400 m

Discussion

Variety hesperium is distributed in the San Juan Mountains and Spanish Peaks area of southern Colorado. It differs from var. eriocephalum in its stiffly erect arrays. Plants from the Spanish Peaks area approach var. eriocephalum.

Selected References

None.

Lower Taxa

None.

"fine" is not a number.

villous +  and glabrous +
villous +, glabrous +  and arachnoid-tomentose +
short-tailed +
spineless +  and twisted +
dentate +, entire +  and spine-tipped +
usually stiffly ascending +  and spreading +
innermost +
scarious +
not differentiated +
indeterminate +  and determinate +
David J. Keil +
(Eastwood) D. J. Keil +
sessile +, winged-petiolate +  and spiny +
decurrent +
Cnicus hesperius +
compound +  and simple +
10 cm100 mm <br />0.1 m <br /> (30 cm300 mm <br />0.3 m <br />) +
1cm;5cm +
10-nerved or 20-nerved +  and rugose +
spiny-fringed +
tawny +  and white +
? (?) +  and ? (?) +
Tall mountain thistle +
actinomorphic +
pale +  and deep purple +
1.4 cm14 mm <br />0.014 m <br /> (2.1 cm21 mm <br />0.021 m <br />) +
compressed +  and ovoid +
fertile +  and bisexual +
2700–3400 m +
gray-canescent +  and glabrous +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Rocky slopes, subalpine meadows, forest openings +
indeterminate +
nodding +  and erect +
each +  and sessile +
suffused with dark purple +  and green +
2 cm20 mm <br />0.02 m <br /> (5 cm50 mm <br />0.05 m <br />) +
broadly ovoid;campanulate +
2 cm20 mm <br />0.02 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
1.5 cm15 mm <br />0.015 m <br /> (5 cm50 mm <br />0.05 m <br />) +
sessile +  and petiolate +
villous +  and tomentose +
cauline +  and basal +
bristle-tipped +
deltate +, usually narrowly triangular +  and more or less linear +
0.2 cm2 mm <br />0.002 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
3-lobed +, lance-oblong +  and broadly triangular +
2-carpellate +
persistent +
0.8 cm8 mm <br />0.008 m <br /> (1.7 cm17 mm <br />0.017 m <br />) +
0 cm0 mm <br />0 m <br /> (14 cm140 mm <br />0.14 m <br />) +
Flowering summer (Jul–Sep). +
spine-tipped +  and plane +
middle +  and outer +
papillate +  and smooth +
sessile +  and winged-petiolate +
bearing subulate enations +, hairy +  and bristly +
flat;convex +
glutinous +
tawny;white +
setiform +  and plumose +
exalbuminous +
subequal +
0.7 cm7 mm <br />0.007 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
branched +, simple +  and sparingly branched +
1 +  and several +
50 cm500 mm <br />0.5 m <br /> (150 cm1,500 mm <br />1.5 m <br />) +
appendaged +  and truncate +
dilated +  and swollen +
enlarged +
0.3 cm3 mm <br />0.003 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
Cirsium hesperium +
Cirsium eatonii var. hesperium +
Cirsium eatonii +
variety +
cylindric +
expanded +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
bristly-dentate to coarsely +
arachnoid-tomentose +
slender +
0.45 cm4.5 mm <br />0.0045 m <br /> (1 cm10 mm <br />0.01 m <br />) +
10 cm100 mm <br />0.1 m <br /> (150 cm1,500 mm <br />1.5 m <br />) +
tree +, vine +, shrub +  and subshrub +