Cirsium occidentale var. venustum

(Greene) Jepson

Man. Fl. Pl. Calif., 1167. 1925.

Common names: Venus thistle
Endemic
Basionym: Carduus venustus Greene Proc. Acad. Nat. Sci. Philadelphia 44: 359. 1893
Synonyms: Cirsium occidentale subsp. venustum (Greene) Petrak Cirsium proteanum
Treatment appears in FNA Volume 19. Treatment on page 140. Mentioned on page 137, 138, 139.

Plants usually erect, usually 50–300 cm, variably tomentose, sometimes ± glabrate. Heads sometimes in tight clusters at ends of peduncles, usually long-pedunculate, elevated well above proximal leaves. Involucres usually longer than wide, 2–6 cm, subglabrous to densely arachnoid, usually without fine trichomes connecting tips of adjacent phyllaries. Phyllaries imbricate, outer and mid apices ascending to rigidly spreading or reflexed, straight, 5–20+ × usually 2–3 mm. Corollas usually ± red (white, pink, rarely purple), 23–35 mm. 2n = 30.


Phenology: Flowering spring–summer (Apr–Jul).
Habitat: Foothill oak-pine woodlands, grasslands, chaparral, pinyon-juniper woodlands, Joshua tree woodlands, roadsides
Elevation: 200–2300 m

Discussion

Variety venustum has the widest ecological range of the races of C. occidentale. Populations occur within a few miles of the California coast in the North and South Coast Ranges and western Transverse Range and range eastward across the state into scattered sites in the Sierra Nevada to the higher elevations of the arid mountains of the western Mojave Desert and adjacent areas of the southwestern Great Basin Desert. Most populations of these plants can be recognized by their striking red to reddish pink corollas. The heads are sometimes visited by hummingbirds as well as by a variety of insects. Intermediates have been documented between var. venustum and vars. californicum and candidissimum.

Selected References

None.

Lower Taxa

None.

"fine" is not a number.

arachnoid-tomentose +
short-tailed +
spineless +  and twisted +
dentate +, entire +  and spine-tipped +
deflexed +  and spreading or ascending +
innermost +
scarious +
not differentiated +
corymbiform +, paniculiform +, subcapitate +, spiciform +  and racemiform +
indeterminate +  and determinate +
David J. Keil +
(Greene) Jepson +
sessile +  and petiolate +
spiny-winged +
not +, decurrent +  and tapered +
Carduus venustus +
compound +  and simple +
6 cm60 mm <br />0.06 m <br /> (40 cm400 mm <br />0.4 m <br />) +
pinnatifid;oblong-elliptic;oblanceolate +
1.5cm;10cm +
10-nerved or 20-nerved +  and rugose +
ascending;spreading +
tawny +  and white +
Venus thistle +
actinomorphic +
2.3 cm23 mm <br />0.023 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
compressed +  and ovoid +
fertile +  and bisexual +
Calif. +  and Nev. +
200–2300 m +
glabrate +  and white-tomentose +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Foothill oak-pine woodlands, grasslands, chaparral, pinyon-juniper woodlands, Joshua tree woodlands, roadsides +
long-pedunculate +
indeterminate +
each +  and sessile +
1.5 cm15 mm <br />0.015 m <br /> (5 cm50 mm <br />0.05 m <br />) +
usually longer than wide +
subglabrous +  and densely arachnoid +
ovoid;spheric +
2 cm20 mm <br />0.02 m <br /> (6 cm60 mm <br />0.06 m <br />) +
1.5 cm15 mm <br />0.015 m <br /> (8 cm80 mm <br />0.08 m <br />) +
sessile +  and petiolate +
cauline +  and basal +
bristle-tipped +
with 1-2 pairs +  and undivided +
deltate +, usually narrowly triangular +  and more or less linear +
0.5 cm5 mm <br />0.005 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
entire +  and dentate +
usually lobed +  and dissected +
5 cm50 mm <br />0.05 m <br /> (20 cm200 mm <br />0.2 m <br />) +
ascending +  and rigidly spreading or reflexed +
2-carpellate +
persistent +
1.5 cm15 mm <br />0.015 m <br /> (3 cm30 mm <br />0.03 m <br />) +
1 cm10 mm <br />0.01 m <br /> (30 cm300 mm <br />0.3 m <br />) +
Flowering spring–summer (Apr–Jul). +
imbricate +  and adjacent +
middle +  and outer +
glabrate +  and glabrous +
papillate +  and smooth +
Man. Fl. Pl. Calif., +
bearing subulate enations +, hairy +  and bristly +
flat;convex +
glutinous +
tawny;white +
setiform +  and plumose +
exalbuminous +
subequal +
spreading +  and reflexed +
0.1 cm1 mm <br />0.001 m <br /> (1 cm10 mm <br />0.01 m <br />) +
spiny-winged +, simple +  and branched +
appendaged +  and truncate +
dilated +  and swollen +
enlarged +
0.4 cm4 mm <br />0.004 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
Cirsium occidentale subsp. venustum +  and Cirsium proteanum +
Cirsium occidentale var. venustum +
Cirsium occidentale +
variety +
cylindric +
expanded +
0.5 cm5 mm <br />0.005 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
bristly-dentate to coarsely +
slender +
0.8 cm8 mm <br />0.008 m <br /> (1.8 cm18 mm <br />0.018 m <br />) +
5 cm50 mm <br />0.05 m <br /> (400 cm4,000 mm <br />4 m <br />) +
glabrate +  and tomentose +