Cirsium occidentale var. californicum

(A. Gray) D. J. Keil & C. E. Turner

Phytologia 73: 315. 1992.

Common names: California thistle
IllustratedEndemic
Basionym: Cirsium californicum A. Gray in War Department [U.S.], Pacif. Railr. Rep. 4(5): 112. 1857
Synonyms: Cirsium bernardinum (Greene) Petrak Cirsium californicum var. bernardinum (Greene) Petrak Cirsium californicum subsp. pseudoreglense Petrak
Treatment appears in FNA Volume 19. Treatment on page 139. Mentioned on page 137, 140.

Plants erect, usually 50–200 cm, thinly to densely gray-tomentose, sometimes glabrate. Leaf faces abaxially green to gray, adaxially gray. Heads in ± open clusters, short to long-pedunculate, elevated well above proximal leaves. Involucres usually about as wide as long, 1.5–5 cm, subglabrous to densely arachnoid. Phyllaries usually imbricate, mid apices appressed to loosely spreading or ascending, sometimes twisted, usually less than 1 cm (but sometimes much longer), 1–3 mm. Corollas white to light purple or rose, 18–35 mm. 2n = 28, 29, 30 (as C. californicum).


Phenology: Flowering spring–summer (Apr–Aug).
Habitat: Pine-oak woodlands, riparian woodlands, chaparral, openings in mixed evergreen forests, roadsides
Elevation: 100–2200 m

Discussion

Variety californicum occurs in both coastal and interior mountains of California from the northern South Coast Range and the northern Sierra Nevada to the mountains of southwestern California. Considerable variation exists in head size, corolla color, and in length and display of phyllary appendages. In several areas of its range, the predominantly white- to light purple-flowered var. californicum occurs with red-flowered var. venustum. These plants are highly interfertile (H. Wells 1983; D. J. Keil and C. E. Turner 1992). Introgressive hybridization among them has resulted in a variety of emergent phenotypes and may have contributed to the variation within var. californicum.

Selected References

None.

Lower Taxa

None.

"fine" is not a number.

30 +, 29 +  and 28 +
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 +
(A. Gray) D. J. Keil & C. E. Turner +
sessile +  and petiolate +
spiny-winged +
not +, decurrent +  and tapered +
Cirsium californicum +
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 +
California thistle +
actinomorphic +
white +  and light purple or rose +
1.8 cm18 mm <br />0.018 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
compressed +  and ovoid +
fertile +  and bisexual +
100–2200 m +
glabrate +  and white-tomentose +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Pine-oak woodlands, riparian woodlands, chaparral, openings in mixed evergreen forests, roadsides +
indeterminate +
each +  and sessile +
1.5 cm15 mm <br />0.015 m <br /> (5 cm50 mm <br />0.05 m <br />) +
subglabrous +  and densely arachnoid +
ovoid;spheric +
1.5 cm15 mm <br />0.015 m <br /> (5 cm50 mm <br />0.05 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 +
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
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–Aug). +
middle +  and outer +
glabrate +  and glabrous +
papillate +  and smooth +
bearing subulate enations +, hairy +  and bristly +
flat;convex +
glutinous +
tawny;white +
setiform +  and plumose +
exalbuminous +
subequal +
Illustrated +  and Endemic +
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 bernardinum +, Cirsium californicum var. bernardinum +  and Cirsium californicum subsp. pseudoreglense +
Cirsium occidentale var. californicum +
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 gray-tomentose +