Cirsium clavatum

(M. E. Jones) Petrak

Beih. Bot. Centralbl. 35(2): 310. 1917.

Endemic
Basionym: Cnicus clavatus M. E. Jones Proc. Calif. Acad. Sci., ser. 2, 5: 704. 1895
Treatment appears in FNA Volume 19. Treatment on page 126. Mentioned on page 103, 105, 108, 127, 129, 130.

Biennials or monocarpic or polycarpic perennials, 20–100 cm; taproots sometimes with branched caudices. Stems 1–several, erect or ascending, glabrous or thinly arachnoid-tomentose; branches 0–10+, slender, usually arising in distal 1/2, ascending. Leaves: blades oblong to oblanceolate or elliptic, 5–40 × 3–11 cm, unlobed and merely spinulose-dentate or more commonly regularly deeply pinnatifid, lobes well separated to crowded, linear to triangular-ovate, ascending-spreading to retrorse, merely spinulose to coarsely dentate or proximally few-lobed, main spines 2–5 (–7) mm, slender, abaxial faces green to gray, glabrous or thinly to densely arachnoid-tomentose, sometimes glabrate, often villous with septate trichomes along veins, adaxial green, glabrous; basal usually present at flowering, sessile or petiolate; principal cauline well distributed, proximal usually winged-petiolate, mid sessile, decurrent as spiny wings 1–3 cm; distal cauline ± reduced. Heads few–many, borne singly or clustered in corymbiform, paniculiform, or racemiform arrays at tips of main-stem and branches, sometimes also in distal axils not closely subtended by clustered leafy bracts. Peduncles 0–30 cm. Involucres ovoid to campanulate, 1.5–3 × 1–3 cm, glabrous to thinly arachnoid-tomentose and/or villous-ciliate, with long septate trichomes connecting adjacent phyllaries. Phyllaries in 5–6 series, imbricate or subequal, outer green or with maroon to dark-brown subapical patch or appendage, linear to ovate, abaxial faces with narrow glutinous ridge that may concealed by trichomes; outer and middle with bases appressed, apical appendages erect or ascending, ovate to linear-lanceolate or acicular, entire or spinulose to broadly expanded, scarious, and erose-dentate, apical appendages, spines erect or ascending, 1–5 mm, ± flattened; apices of inner sometimes flexuous or reflexed, narrow, flat, entire or ± expanded, scarious and lacerate-dentate. Corollas creamy white to pale pinkish, 16–20 mm, tubes 6.5–9 mm, throats 4–7.5 mm, lobes 4–6 mm; style tips 3.5–5 mm. Cypselae tan to dark-brown, 5–6 mm, apical collars not or scarcely differentiated; pappi 14–16 mm.

Distribution

V19-90-distribution-map.gif

Colo., Utah, Wyo., Central Rocky Mountains

Discussion

Varieties 3 (3 in the flora).

Cirsium clavatum is a polymorphic and variable species.

Selected References

None.

Key

1 Involucres densely villous or tomentose with long, septate trichomes connecting adjacent phyllaries Cirsium clavatum var. osterhoutii
1 Involucres glabrous or thinly arachnoid-tomentose with fine, non-septate trichomes > 2
2 Some or all of the phyllaries usually with dilated, scarious, erose to fringed appendages; mostly Colorado and Wyoming Cirsium clavatum var. americanum
2 Phyllaries usually entire; w Colorado and Utah Cirsium clavatum var. clavatum

"fine" is not a number.

... more about "Cirsium clavatum"
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 +
erose-dentate +, spinulose +  and entire +
ascending +  and erect +
ovate +  and linear-lanceolate or acicular +
racemiform +, paniculiform +  and corymbiform +
indeterminate +  and determinate +
David J. Keil +
(M. E. Jones) Petrak +
petiolate +  and sessile +
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 ? (?) +
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. +, Utah +, Wyo. +  and Central Rocky Mountains +
gray-canescent +  and glabrous +
lacerate-dentate +  and entire +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
clustered +  and or +
indeterminate +
each +  and sessile +
1.5 cm15 mm <br />0.015 m <br /> (3 cm30 mm <br />0.03 m <br />) +
glabrous +  and thinly arachnoid-tomentose +
ovoid;campanulate +
1 cm10 mm <br />0.01 m <br /> (3 cm30 mm <br />0.03 m <br />) +
sessile +  and petiolate +
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 />) +
imbricate +  and adjacent +
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 +
0.1 cm1 mm <br />0.001 m <br /> (0.5 cm5 mm <br />0.005 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 />) +
maroon +  and dark-brown +
Compositae +
Cirsium clavatum +
species +
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 />) +