Cirsium clavatum var. clavatum

Common names: Fish Lake thistle
Endemic
Synonyms: Cirsium clavatum var. markaguntense
Treatment appears in FNA Volume 19. Treatment on page 127. Mentioned on page 128.

Abaxial leaf faces glabrous to ± tomentose. Involucres ovoid to campanulate, 1.5–2 × 1–2 cm, glabrous or thinly arachnoid-tomentose with fine, non-septate trichomes. Phyllaries in 5–6 series, strongly imbricate, green or with dark subapical patch, lanceolate to ovate, abaxial faces with narrow glutinous ridge; outer and middle bases appressed, apical appendages erect or ascending, linear-lanceolate, entire, usually not scarious or fringed, acicular-acuminate, spines erect or ascending, 3–6 mm; apices of inner sometimes flexuous or reflexed, narrow, flat, and entire or minutely toothed to slightly expanded and erose.


Phenology: Flowering summer (Jun–Sep).
Habitat: Sagebrush scrub, aspen groves, meadows, openings in montane coniferous forests
Elevation: 2100–3400 m

Discussion

Cirsium clavatum grows from the Colorado Plateau of central Utah eastward into the Rocky Mountains of western Colorado. R. J. Moore and C. Frankton (1965) suggested that C. clavatum (i.e., var. clavatum here) is a derivative of hybridization between C. eatonii and C. centaureae (i.e., C. clavatum var. americanum here). S. L. Welsh (1983) noted that the distribution of var. clavatum is distinct from those of var. americanum and C. eatonii. It is certainly possible that ancient hybridization may have contributed to the origin of var. clavatum, but there is no indication that the modern plants over most of its range are hybrids. The morphology of certain plants from southeastern Utah indicates a possibility of hybridization between C. clavatum and C. eatonii var. eatonii. The close relationship between var. clavatum and var. americanum is evident in the many overlapping vegetative features. The recently described C. clavatum var. markaguntense S. L. Welsh is a minor variant with subentire glabrous leaves.

Selected References

None.

Lower Taxa

None.

"fine" is not a number.

green +  and gray +
villous +, glabrate +, glabrous or +  and thinly densely arachnoid-tomentose +
short-tailed +
spineless +  and twisted +
dentate +, entire +  and spine-tipped +
erect +  and spreading +
innermost +
scarious +
ascending +  and erect +
acicular-acuminate +, fringed +  and linear-lanceolate +
racemiform +, paniculiform +  and corymbiform +
indeterminate +  and determinate +
David J. Keil +
(M. E. Jones) Petrak +
petiolate +  and sessile +
toothed +  and entire +
decurrent +
Cnicus clavatus +
compound +  and simple +
5 cm50 mm <br />0.05 m <br /> (40 cm400 mm <br />0.4 m <br />) +
pinnatifid;unlobed;oblong;oblanceolate or elliptic +
3cm;11cm +
10-nerved or 20-nerved +  and rugose +
ascending;arising +
slender +
tawny +  and white +
? (?) +  and ? (?) +
Fish Lake thistle +
actinomorphic +
creamy white +  and pale pinkish +
1.6 cm16 mm <br />0.016 m <br /> (2 cm20 mm <br />0.02 m <br />) +
tan +  and dark-brown +
compressed +  and ovoid +
fertile +  and bisexual +
Colo. +  and Utah. +
2100–3400 m +
gray-canescent +  and glabrous +
lacerate-dentate +  and entire +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Sagebrush scrub, aspen groves, meadows, openings in montane coniferous forests +
clustered +  and or +
indeterminate +
each +  and sessile +
1.5 cm15 mm <br />0.015 m <br /> (2 cm20 mm <br />0.02 m <br />) +
arachnoid-tomentose +  and glabrous +
ovoid;campanulate +
1 cm10 mm <br />0.01 m <br /> (2 cm20 mm <br />0.02 m <br />) +
sessile +  and petiolate +
glabrous +  and more or less tomentose +
cauline +  and basal +
bristle-tipped +
ascending-spreading;retrorse +
linear +  and triangular-ovate +
slender +
0.5 cm5 mm <br />0.005 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
few-lobed +  and dentate +
0.2 cm2 mm <br />0.002 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
entire +  and dentate +
usually lobed +  and dissected +
with maroon to dark-brown subapical patch or appendage +  and green +
linear +  and ovate +
2-carpellate +
persistent +
1.4 cm14 mm <br />0.014 m <br /> (1.6 cm16 mm <br />0.016 m <br />) +
0 cm0 mm <br />0 m <br /> (30 cm300 mm <br />0.3 m <br />) +
Flowering summer (Jun–Sep). +
middle +  and outer +
papillate +  and smooth +
Beih. Bot. Centralbl. +
bearing subulate enations +, hairy +  and bristly +
flat;convex +
glutinous +
tawny;white +
setiform +  and plumose +
exalbuminous +
subequal +
ascending +  and erect +
flattened +
0.3 cm3 mm <br />0.003 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
spiny-winged +, simple +  and branched +
ascending +  and erect +
1 +  and several +
appendaged +  and truncate +
dilated +  and swollen +
enlarged +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
Cirsium clavatum var. markaguntense +
Cirsium clavatum var. clavatum +
Cirsium clavatum +
variety +
cylindric +
expanded +
0.4 cm4 mm <br />0.004 m <br /> (0.75 cm7.5 mm <br />0.0075 m <br />) +
bristly-dentate to coarsely +
slender +
0.65 cm6.5 mm <br />0.0065 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
perennial +  and biennial +
polycarpic +  and monocarpic +
20 cm200 mm <br />0.2 m <br /> (100 cm1,000 mm <br />1 m <br />) +
tree +, vine +, shrub +  and subshrub +
1 cm10 mm <br />0.01 m <br /> (3 cm30 mm <br />0.03 m <br />) +