Cirsium crassicaule

(Greene) Jepson

Fl. W. Calif., 506. 1901.

Common names: Slough thistle
EndemicConservation concern
Basionym: Carduus crassicaulis Greene Proc. Acad. Nat. Sci. Philadelphia 44: 357. 1893
Treatment appears in FNA Volume 19. Treatment on page 132. Mentioned on page 103, 104.

Annuals or biennials, (60–) 100–300 cm; taprooted. Stems usually 1, erect, stout, (hollow, 2–10 cm diam. at base), openly branched distally, thinly arachnoid, villous with jointed trichomes, at least proximally. Leaves: blades elliptic to broadly oblanceolate, 15–70 × 30–150+ cm, flat, pinnatifid 1/2–2/3 distance to midvein, larger usually with broad sinuses, lobes broad, few lobed or dentate, main spines 3–8 mm, abaxial faces gray-tomentose, adaxial thinly arachnoid-tomentose, sometimes midveins with jointed trichomes; basal present or withered at flowering, winged-petiolate; principal cauline sessile, progressively reduced distally, bases clasping or short-decurrent 1–2 cm; distal cauline reduced, becoming bractlike, sometimes spinier than proximal. Heads 1–several at branch tips, closely subtended by clustered leafy bracts or not, collectively forming open, corymbiform or paniculiform arrays. Peduncles 0–15 cm. Involucres ovoid to campanulate, 1.5–3 × 1.5–3 cm, ± glabrous. Phyllaries in 5–7 series, weakly unequal, dark green to brownish, lanceolate (outer) to linear (inner), abaxial faces without (or with very obscure) glutinous ridge; outer and middle appressed or apices spreading, at least outer irregularly spiny-fringed, finely serrulate, spines slender, 3–5 mm; apices of inner erect, abaxial faces gray-tomentose, ± twisted. Corollas pale rose-purple (white), 19–26 mm, tubes 9–12 mm, throats 4–6 mm, lobes 5–9 mm; style tips 3.5–4.5 mm. Cypselae dark-brown, 5–5.5 mm, collars narrow, ± stramineous; pappi 15–20 mm. 2n = 32.


Phenology: Flowering spring (Apr–Jun).
Habitat: Freshwater marshes, canal banks
Elevation: 5–100 m

Discussion

Cirsium crassicaule is known only from a few sites in the San Joaquin Valley. Some populations are threatened by habitat modification and development pressures.

Selected References

None.

Lower Taxa

None.

"fine" is not a number."broad" is not a number.

... more about "Cirsium crassicaule"
inner +  and adaxial +
arachnoid-tomentose +  and gray-tomentose +
short-tailed +
spineless +  and twisted +
dentate +, entire +  and spine-tipped +
erect +  and spreading +
innermost +
scarious +
paniculiform +, corymbiform +  and open +
indeterminate +  and determinate +
David J. Keil +
(Greene) Jepson +
winged-petiolate +
short-decurrent +  and clasping +
decurrent +
1 cm10 mm <br />0.01 m <br /> (2 cm20 mm <br />0.02 m <br />) +
Carduus crassicaulis +
compound +  and simple +
15 cm150 mm <br />0.15 m <br /> (70 cm700 mm <br />0.7 m <br />) +
pinnatifid;elliptic;broadly oblanceolate +
30cm;150cm +
10-nerved or 20-nerved +  and rugose +
tawny +  and white +
? (?) +  and ? (?) +
stramineous +
Slough thistle +
actinomorphic +
pale rose-purple +
1.9 cm19 mm <br />0.019 m <br /> (2.6 cm26 mm <br />0.026 m <br />) +
compressed +  and ovoid +
fertile +  and bisexual +
5–100 m +
gray-tomentose +
gray-canescent +  and glabrous +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Freshwater marshes, canal banks +
indeterminate +
each +  and sessile +
1.5 cm15 mm <br />0.015 m <br /> (3 cm30 mm <br />0.03 m <br />) +
ovoid;campanulate +
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 +
dentate +, lobed +  and few +
0.3 cm3 mm <br />0.003 m <br /> (0.8 cm8 mm <br />0.008 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 />) +
0 cm0 mm <br />0 m <br /> (15 cm150 mm <br />0.15 m <br />) +
Flowering spring (Apr–Jun). +
middle +  and outer +
papillate +  and smooth +
Fl. W. Calif., +
bearing subulate enations +, hairy +  and bristly +
flat;convex +
glutinous +
tawny;white +
setiform +  and plumose +
exalbuminous +
subequal +
Endemic +  and Conservation concern +
0.3 cm3 mm <br />0.003 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
appendaged +  and truncate +
dilated +  and swollen +
enlarged +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.45 cm4.5 mm <br />0.0045 m <br />) +
Compositae +
Cirsium crassicaule +
species +
cylindric +
expanded +
0.4 cm4 mm <br />0.004 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
bristly-dentate to coarsely +
slender +
0.9 cm9 mm <br />0.009 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
60 cm600 mm <br />0.6 m <br /> (100 cm1,000 mm <br />1 m <br />) +
biennial +  and annual +
100 cm1,000 mm <br />1 m <br /> (300 cm3,000 mm <br />3 m <br />) +
tree +, vine +, shrub +  and subshrub +