Cirsium scariosum var. scariosum

IllustratedEndemic
Synonyms: Cirsium butleri (Rydberg) Petrak Cirsium lacerum (Rydberg) Petrak Cirsium magnificum (A. Nelson) Petrak Cirsium minganense Victorin
Treatment appears in FNA Volume 19. Treatment on page 155. Mentioned on page 149, 152, 154, 156, 157, 1.

Plants erect, caulescent or occasionally acaulescent, 15–200 cm. Stems usually simple, very leafy, glabrous or villous to tomentose with septate trichomes. Leaves: blades linear to oblong, oblanceolate, or narrowly elliptic, pinnately lobed or often unlobed, larger leaf spines usually 1 cm or less, abaxial faces glabrous to gray-tomentose, adaxial glabrous or villous with septate trichomes; distal narrow, ± thin, often unpigmented proximally or tinged pink or purplish, spines numerous, weak. Heads 1–10+, sessile or short-pedunculate, tightly clustered at stem tips, usually subtended and ± overtopped by crowded, distal leaves. Involucres 2–3.5 cm. Phyllaries: outer and mid lanceolate to ovate, spines slender to stout, 1–8 mm; apices of inner acuminate and entire or abruptly expanded into scarious, erose-toothed appendages. Corollas white to purple, 20–28 mm, tubes 9–14.5 mm, throats 6–10 mm, lobes 3.5–6 mm; style tips 3–6.5 mm. Cypselae 4.5–6.5 mm; pappi 17–25 mm. 2n = 34 (as C. foliosum), 36.


Phenology: Flowering summer (Jun–Sep).
Habitat: Moist, sometimes saline soils, meadows, ditches, stream banks, forest openings, sagebrush zone to subalpine forests
Elevation: 0 (Quebec) or 600–2800 m

Distribution

V19-151-distribution-map.gif

Alta., B.C., Que., Calif., Colo., Idaho, Mont., Oreg., Utah, Wash., Wyo.

Discussion

The presence of Cirsium scariosum on the islands of the Mingan Archipelago in Quebec, some 3200 km east of the Rocky Mountains populations, has led to alternative hypotheses regarding the disjunction. Frère Marie-Victorin (1925) hypothesized that the disjunct distribution of C. minganense from what he called C. foliosum (Hooker) Candolle was a result of migration during deglaciation (18,000 to ca. 8000 BP) from a glacial refugium in western North America to eastern Canada in the barren habitats along the receding ice front. Later (1938) he presented a second hypothesis that Pleistocene glacial events had divided a preglacial range into vicariant populations that survived in separate refugia in western and eastern regions. R. J. Moore and C. Frankton (1967) argued that the disjunction is modern, resulting from a chance introduction of C. scariosum from western North America to Quebec in the early twentieth century. They reached this conclusion because early collectors that had visited the Mingan Archipelago had failed to collect this conspicuous thistle.

Hybrids are known between Cirsium scariosum var. scariosum and C. eatonii var. murdockii in northern Wyoming.

Selected References

None.

Lower Taxa

None.

"fine" is not a number."thin" is not a number.

glabrous +  and gray-tomentose +
villous +  and glabrous +
short-tailed +
spineless +  and twisted +
erect +  and spreading +
innermost +
expanded +
scarious +
erose-toothed +
subcapitate +, racemiform +  and spiciform +
indeterminate +  and determinate +
David J. Keil +
Nuttall +
winged-petiolate +  and sessile +
decurrent +
Asteraceae tribe Cynareae +
compound +  and simple +
linear to elliptic +
5 cm50 mm <br />0.05 m <br /> (20 cm200 mm <br />0.2 m <br />) +
unlobed;lobed;linear;oblong oblanceolate or narrowly elliptic +
3cm;7cm +
10-nerved or 20-nerved +  and rugose +
tawny +  and white +
? (?) +  and ? (?) +
actinomorphic +
white +  and purple +
2 cm20 mm <br />0.02 m <br /> (2.8 cm28 mm <br />0.028 m <br />) +
light +  and dark-brown +
compressed +  and ovoid +
fertile +  and bisexual +
unpigmented proximally or tinged pink or purplish +
Alta. +, B.C. +, Que. +, Calif. +, Colo. +, Idaho +, Mont. +, Oreg. +, Utah +, Wash. +  and Wyo. +
0 (Quebec) or 600–2800 m +
gray-canescent +  and glabrous +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Moist, sometimes saline soils, meadows, ditches, stream banks, forest openings, sagebrush zone to subalpine forests +
short-pedunculate +  and sessile +
crowded +  and singly +
indeterminate +
each +  and sessile +
2 cm20 mm <br />0.02 m <br /> (4 cm40 mm <br />0.04 m <br />) +
glabrate +  and arachnoid +
ovoid;hemispheric +
2 cm20 mm <br />0.02 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
1.5 cm15 mm <br />0.015 m <br /> (6 cm60 mm <br />0.06 m <br />) +
sessile +  and petiolate +
cauline +  and basal +
bristle-tipped +
lobed +, spinose-dentate +, linear-lanceolate +  and broadly triangular +
0.2 cm2 mm <br />0.002 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
entire +  and dentate +
scarious-fringed +  and entire +
rounded +
2-carpellate +
white +  and tan +
persistent +
1.7 cm17 mm <br />0.017 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
0 cm0 mm <br />0 m <br /> (10 cm100 mm <br />0.1 m <br />) +
Flowering summer (Jun–Sep). +
middle +  and outer +
weakly to strongly +
short-caulescent +  and acaulescent +
papillate +  and smooth +
Trans. Amer. Philos. Soc., n. s. +
bearing subulate enations +, hairy +  and bristly +
flat;convex +
glutinous +
tawny;white +
setiform +  and plumose +
exalbuminous +
subequal +
Illustrated +  and Endemic +
erect +  and spreading +
flattened +
Slender (?) +  and Stout (?) +
0.1 cm1 mm <br />0.001 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
leafy +  and simple +
appendaged +  and truncate +
dilated +  and swollen +
enlarged +
0.3 cm3 mm <br />0.003 m <br /> (0.65 cm6.5 mm <br />0.0065 m <br />) +
Cirsium butleri +, Cirsium lacerum +, Cirsium magnificum +  and Cirsium minganense +
Cirsium scariosum var. scariosum +
Cirsium scariosum +
variety +
cylindric +
expanded +
0.6 cm6 mm <br />0.006 m <br /> (1 cm10 mm <br />0.01 m <br />) +
tipped +  and spineless +
scabro-denticulate +  and narrowed +
expanded +
bristly-dentate to coarsely +
slender +
0.9 cm9 mm <br />0.009 m <br /> (1.45 cm14.5 mm <br />0.0145 m <br />) +
taprooted +, caulescent +  and acaulescent +
perennial +  and biennial +
0 cm0 mm <br />0 m <br /> (200 cm2,000 mm <br />2 m <br />) +
acaulescent +  and caulescent +