Cirsium arizonicum var. chellyense

(R. J. Moore & Frankton) D. J. Keil

Sida 21: 209. 2004.

Common names: Navajo thistle
EndemicConservation concern
Basionym: Cirsium chellyense R. J. Moore & Frankton Canad. J. Bot. 52: 547, plate 2. 1974
Synonyms: Cirsium chuskaense R. J. Moore & Frankton Cirsium navajoense R. J. Moore & Frankton
Treatment appears in FNA Volume 19. Treatment on page 144. Mentioned on page 142.

Stems glabrous or villous to tomentose with septate trichomes. Leaf-blades deeply 1–2× divided, (lobes many, narrow, closely spaced), faces glabrous or abaxial villous along midveins with septate trichomes; main marginal spines usually very slender, 5–12 mm; cauline bases usually decurrent as spiny wings to 30 mm. Involucres cylindric to narrowly ovoid. Phyllary spines slender to ± stout, 1–20 mm. Corollas usually reddish purple, 25–32 mm, tubes 7–11, throats 4–7.5 mm, lobes 11–16 mm; style tips 2.5–3.5 mm. 2n = 34 (as C. chuskaense).


Phenology: Flowering summer (Jun–Sep).
Habitat: Desert scrub, grasslands, pine-oak-juniper woodlands, ponderosa pine forests
Elevation: 1600–2800 m

Discussion

Of conservation concern.

R. J. Moore and C. Frankton (1974b) recognized three narrowly defined new species in the Cirsium arizonicum complex, all from a small area in the Defiance Plateau and Chuska Mountains in northeastern Arizona and northwestern New Mexico. The characters used to differentiate these taxa break down when additional specimens are examined, and they are all combined here as a single variety of C. arizonicum.

Selected References

None.

Lower Taxa

None.

"fine" is not a number.

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 +
(R. J. Moore & Frankton) D. J. Keil +
sessile +  and winged-petiolate +
decurrent +
Cirsium chellyense +
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 +
? (?) +  and ? (?) +
Navajo thistle +
actinomorphic +
reddish purple +
2.5 cm25 mm <br />0.025 m <br /> (3.2 cm32 mm <br />0.032 m <br />) +
compressed +  and ovoid +
fertile +  and bisexual +
Ariz. +  and N.Mex. +
1600–2800 m +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Desert scrub, grasslands, pine-oak-juniper woodlands, ponderosa pine 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 +
cylindric;narrowly ovoid +
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 +
0.5 cm5 mm <br />0.005 m <br /> (1.2 cm12 mm <br />0.012 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 summer (Jun–Sep). +
middle +  and outer +
weakly to strongly +
slender +  and more or less stout +
0.1 cm1 mm <br />0.001 m <br /> (2 cm20 mm <br />0.02 m <br />) +
papillate +  and smooth +
bearing subulate enations +, hairy +  and bristly +
flat;convex +
glutinous +
inconspicuous +
tawny;white +
setiform +  and plumose +
exalbuminous +
subequal +
Endemic +  and Conservation concern +
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 +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
Cirsium chuskaense +  and Cirsium navajoense +
Cirsium arizonicum var. chellyense +
Cirsium arizonicum +
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 +
0.7 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 />) +