Cirsium douglasii

de Candolle in A. P. de Candolle and A. L. P. P. de Candolle

in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 6: 643. 1838.

Common names: California swamp or Douglas’s thistle
IllustratedEndemic
Treatment appears in FNA Volume 19. Treatment on page 133. Mentioned on page 104, 108, 160.

Biennials or short-lived monocarpic perennials, 60–250 cm; taprooted. Stems 1–several, erect or ascending, densely gray-tomentose; branches few–many, ascending to spreading. Leaves: blades oblongelliptic to obovate, 10–60 × 2–15 cm, unlobed or shallowly to deeply pinnatifid, lobes lanceolate to ovate-triangular, ascending to spreading, entire to coarsely dentate or lobed, main spines slender to stout, 2–30 mm, faces densely gray-tomentose, rarely glabrate; basal present at flowering, petiolate; principal cauline well distributed, proximal winged-petiolate, distal sessile, bases auriculate-clasping or decurrent as a spiny wing 1–3 cm; distalmost well separated, bractlike. Heads 10–many, often crowded at branch tips, collectively forming paniculiform arrays. Peduncles 0–4 (–8) cm. Involucres ovoid to hemispheric, 1.5–3 cm, 2–4.5 cm diam, loosely arachnoid on phyllary margins or glabrate. Phyllaries in 6–8 series, imbricate, often with dark purple patch near tip, ovatelanceolate (outer) to linear-lanceolate (inner), abaxial faces with linear to elliptic glutinous ridge; outer and middle appressed, entire, spines spreading, 1–9 mm; apices of inner often purple-tinged, often flexuous, flattened, spineless, scabrid. Corollas rose-purple (white or pinkish-tinged), 18–21 mm, tubes 8–9 mm, throats 5–6 mm (abruptly expanded), lobes 5–6 mm; style tips 3–4.5 mm. Cypselae dark-brown to black, 5–6 mm, apical collars not differentiated; pappi 15–20 mm.

Discussion

Varieties 2 (2 in the flora).

Selected References

None.

Key

1 Distal cauline leaves with larger spines mostly less than 7 mm Cirsium douglasii var. breweri
1 Distal cauline leaves with larger spines usually 7–20 mm Cirsium douglasii var. douglasii

"fine" is not a number."[" is not declared as a valid unit of measurement for this property."]" is not declared as a valid unit of measurement for this property.

... more about "Cirsium douglasii"
short-tailed +
spineless +  and twisted +
dentate +, entire +  and spine-tipped +
erect +  and spreading +
innermost +
scarious +
not differentiated +
paniculiform +
indeterminate +  and determinate +
David J. Keil +
de Candolle in A. P. de Candolle and A. L. P. P. de Candolle +
auriculate-clasping +
decurrent +
Asteraceae tribe Cynareae +
compound +  and simple +
10 cm100 mm <br />0.1 m <br /> (60 cm600 mm <br />0.6 m <br />) +
unlobed or;shallowly deeply pinnatifid +
2cm;15cm +
10-nerved or 20-nerved +  and rugose +
ascending;spreading +
tawny +  and white +
? (?) +  and ? (?) +
California swamp or Douglas’s thistle +
actinomorphic +
1.8 cm18 mm <br />0.018 m <br /> (2.1 cm21 mm <br />0.021 m <br />) +
dark-brown +  and black +
compressed +  and ovoid +
fertile +  and bisexual +
Calif. +, Nev. +  and Oreg. +
glabrate +  and gray-tomentose +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
indeterminate +
each +  and sessile +
2 cm20 mm <br />0.02 m <br /> (4.5 cm45 mm <br />0.045 m <br />) +
glabrate +  and arachnoid +
ovoid;hemispheric +
1.5 cm15 mm <br />0.015 m <br /> (3 cm30 mm <br />0.03 m <br />) +
sessile +  and petiolate +
cauline +  and basal +
bristle-tipped +
ascending;spreading +
lobed +, dentate +, lanceolate +  and ovate-triangular +
0.2 cm2 mm <br />0.002 m <br /> (3 cm30 mm <br />0.03 m <br />) +
entire +  and dentate +
usually lobed +  and dissected +
2-carpellate +
persistent +
1.5 cm15 mm <br />0.015 m <br /> (2 cm20 mm <br />0.02 m <br />) +
dark purple +
4 cm40 mm <br />0.04 m <br /> (8 cm80 mm <br />0.08 m <br />) +
0 cm0 mm <br />0 m <br /> (4 cm40 mm <br />0.04 m <br />) +
middle +  and outer +
weakly to strongly +
papillate +  and smooth +
in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. +
bearing subulate enations +, hairy +  and bristly +
flat;convex +
linear to elliptic +
glutinous +
tawny;white +
setiform +  and plumose +
exalbuminous +
subequal +
Illustrated +  and Endemic +
0.1 cm1 mm <br />0.001 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
spiny-winged +, simple +  and branched +
ascending +  and erect +
1 +  and several +
appendaged +  and truncate +
dilated +  and swollen +
enlarged +
0.3 cm3 mm <br />0.003 m <br /> (0.45 cm4.5 mm <br />0.0045 m <br />) +
Compositae +
Cirsium douglasii +
species +
cylindric +
expanded +
0.5 cm5 mm <br />0.005 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
bristly-dentate to coarsely +
slender +
0.8 cm8 mm <br />0.008 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
perennial +, short-lived +  and biennial +
60 cm600 mm <br />0.6 m <br /> (250 cm2,500 mm <br />2.5 m <br />) +
tree +, vine +, shrub +  and subshrub +
1 cm10 mm <br />0.01 m <br /> (3 cm30 mm <br />0.03 m <br />) +