Cirsium arizonicum var. bipinnatum

(Eastwood) D. J. Keil

Sida 21: 209. 2004.

Common names: Four Corners thistle
Endemic
Basionym: Cnicus drummondii var. bipinnatus Eastwood Zoë 4: 8. 1893
Synonyms: Cirsium bipinnatum (Eastwood) Rydberg Cirsium calcareum (M. E. Jones) Wooton & Standley Cirsium calcareum var. bipinnatum (Eastwood) S. L. Welsh Cirsium calcareum var. pulchellum (Greene ex Rydberg) S. L. Welsh Cirsium diffusum Cirsium pulchellum Cirsium pulchellum subsp. bipinnatum (Eastwood) Petrak Cirsium pulchellum subsp. diffusum (Eastwood) Petrak Cirsium pulchellum var. glabrescens Petrak
Treatment appears in FNA Volume 19. Treatment on page 143. Mentioned on page 142.

Stems glabrous to tomentose, usually without septate trichomes. Leaf-blades unlobed to deeply divided, faces glabrous to tomentose on one or both, usually without septate trichomes; main marginal spines slender to stout, 3–10 mm; cauline bases narrowed to truncate or clasping or decurrent as spiny wings to 30 mm. Involucres cylindric or ovoid to campanulate; spines of mid phyllaries 1–6 mm, slender to very stout. Corollas usually lavender to purple or reddish purple, 22–34 mm, tubes 7–12, throats 4–9 mm, lobes 8–18 mm; style tips 1.2–4.5 mm.


Phenology: Flowering spring–summer (May–Oct).
Habitat: Canyons, rocky slopes, desert scrub, pine-oak-juniper woodlands, openings in montane coniferous forests
Elevation: 900–3100 m

Distribution

V19-127-distribution-map.gif

Ariz., Colo., N.Mex., Utah.

Discussion

Variety bipinnatum grows in the Colorado Plateau of New Mexico, northeastern Arizona, southeastern Utah, and southwestern Colorado south to the Sacramento Mountains of southern New Mexico. It is a polymorphic assemblage of races and local populations with overlapping patterns of variation. Extremes are diverse and strikingly different, and various authors have attempted to segregate variants as species, subspecies, or varieties. Apparently independent segregation of character states of multiple variable characters has resulted in a complex array of local morphotypes. Leaves range from wholly glabrous to densely tomentose on one or both faces. The bases of cauline leaves vary from sessile and not at all decurrent to prominently decurrent with spiny wings to 3 cm. Leaf lobing and spininess are similarly variable. Heads may be solitary at the branch tips or densely clustered. I have been unable to detect patterns that can consistently separate the many forms in any meaningful way.

Selected References

None.

Lower Taxa

None.

"fine" is not a number.

34 +, 32 +  and 30 +
glabrous +  and densely gray tomentose +
glabrate +, glabrous +  and gray-tomentose +
short-tailed +
spineless +  and twisted +
spreading +  and ascending +
innermost +
inconspicuous +
scarious +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.03 cm0.3 mm <br />3.0e-4 m <br />) +
paniculiform +  and corymbiform +
indeterminate +  and determinate +
David J. Keil +
(Eastwood) D. J. Keil +
sessile +  and winged-petiolate +
decurrent +
Cnicus drummondii var. bipinnatus +
compound +  and simple +
3 cm30 mm <br />0.03 m <br /> (40 cm400 mm <br />0.4 m <br />) +
spinulose;shallowly lobed or divided +
1cm;13cm +
with straight or flexuous spines +  and unarmed +
10-nerved or 20-nerved +  and rugose +
tawny +  and white +
clasping +  and truncate +
decurrent +  and narrowed +
Four Corners thistle +
actinomorphic +
pink +  and red lavender or purple +
reddish purple;purple +
2.2 cm22 mm <br />0.022 m <br /> (3.4 cm34 mm <br />0.034 m <br />) +
compressed +  and ovoid +
fertile +  and bisexual +
Ariz. +, Colo. +, N.Mex. +  and Utah. +
900–3100 m +
glabrous +  and tomentose +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Canyons, rocky slopes, desert scrub, pine-oak-juniper woodlands, openings in montane coniferous forests +
indeterminate +
each +  and sessile +
1.5 cm15 mm <br />0.015 m <br /> (4 cm40 mm <br />0.04 m <br />) +
glabrous +  and arachnoid +
ovoid;campanulate +
1 cm10 mm <br />0.01 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
sessile +  and petiolate +
cauline +  and basal +
bristle-tipped +
divided +, lobed +, ovate +  and linear-acuminate +
0.3 cm3 mm <br />0.003 m <br /> (1 cm10 mm <br />0.01 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (3 cm30 mm <br />0.03 m <br />) +
usually lobed +  and dissected +
2-carpellate +
persistent +
1.7 cm17 mm <br />0.017 m <br /> (2.8 cm28 mm <br />0.028 m <br />) +
0 cm0 mm <br />0 m <br /> (15 cm150 mm <br />0.15 m <br />) +
Flowering spring–summer (May–Oct). +
middle +  and outer +
weakly to strongly +
slender to very +
0.1 cm1 mm <br />0.001 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
papillate +  and smooth +
bearing subulate enations +, hairy +  and bristly +
flat;convex +
glutinous +
inconspicuous +
tawny;white +
setiform +  and plumose +
exalbuminous +
subequal +
flexuous +  and straight +
erect +  and reflexed +
flattened +  and cylindric +
Slender (?) +  and Stout (?) +
0.1 cm1 mm <br />0.001 m <br /> (3 cm30 mm <br />0.03 m <br />) +
spiny-winged +, simple +  and branched +
ascending +  and erect +
1 +  and several +
appendaged +  and truncate +
dilated +  and swollen +
enlarged +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.45 cm4.5 mm <br />0.0045 m <br />) +
Cirsium bipinnatum +, Cirsium calcareum +, Cirsium calcareum var. bipinnatum +, Cirsium calcareum var. pulchellum +, Cirsium diffusum +, Cirsium pulchellum +, Cirsium pulchellum subsp. bipinnatum +, Cirsium pulchellum subsp. diffusum +  and Cirsium pulchellum var. glabrescens +
Cirsium arizonicum var. bipinnatum +
Cirsium arizonicum +
variety +
cylindric +
expanded +
0.4 cm4 mm <br />0.004 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
bristly-dentate to coarsely +
slender +
0.7 cm7 mm <br />0.007 m <br /> (1.25 cm12.5 mm <br />0.0125 m <br />) +
30 cm300 mm <br />0.3 m <br /> (150 cm1,500 mm <br />1.5 m <br />) +
tree +, vine +, shrub +  and subshrub +
0 cm0 mm <br />0 m <br /> (3 cm30 mm <br />0.03 m <br />) +