Cirsium wrightii

A. Gray

Smithsonian Contr. Knowl. 5(6): 101. 1853.

Common names: Wright’s marsh thistle
Treatment appears in FNA Volume 19. Treatment on page 131. Mentioned on page 97, 102, 163.

Biennials or monocarpic perennials, 100–300 cm; taproots short with many slender, fibrous lateral roots. Stems usually 1, erect, glabrous to ± tomentose; branches many, usually restricted to distal part of stem, ascending. Leaves: blades oblong to elliptic, 10–60 × 5–20 cm, unlobed and merely spinulose to irregularly dentate or shallowly to deeply pinnatifid, lobes ± broadly triangular, separated by wide sinuses, obtuse to acute, sometimes coarsely toothed or lobed, main spines slender, 1–3 mm, faces thinly arachnoid, soon glabrescent; basal often present at flowering, petioles slender, ± winged; cauline progressively reduced, proximal petiolate, mid and distal sessile, long-decurrent; distalmost linear to narrowly elliptic, bractlike, spinulose to irregularly dentate or shallowly lobed. Heads many, in openly paniculiform arrays, borne singly at tips of peduncles. Peduncles slender, 1–15 cm. Involucres ovoid to hemispheric, 1–2 × 1–2 cm, thinly arachnoid, glabrate. Phyllaries in 8–9 series, strongly imbricate, green, lanceolate (outer) to linear (inner), abaxial faces with prominent glutinous ridge; outer and middle appressed, bodies entire, apices acute, spines spreading, slender, ca. 1 mm; apices of inner often flexuous, acuminate, flat, scabrid-ciliolate. Corollas white to pink-purple, 19–21 mm, tubes 9–10 mm, throats 4–4.5 mm, lobes 5–7 mm; style tips 2–3.5 mm. Cypselae brown, ca. 4.5 mm, apical collars stramineous, 0.2 mm; pappi 15–16 mm.


Phenology: Flowering summer–fall (Aug–Oct).
Habitat: Springs, seeps, marshes, stream banks, often in alkaline soil
Elevation: 1100–2600 m

Distribution

V19-99-distribution-map.gif

Ariz., N.Mex., Tex., Mexico (Chihuahua), Mexico (Sonora)

Discussion

Of conservation concern.

Wright’s thistle occurs from the mountains of south-central New Mexico eastward to the cienegas of the adjacent southwestern Great Plains. Cirsium wrightii is listed by the state of New Mexico as a species of concern. The one known site in Cochise County, Arizona, is apparently historic.

Hybrids are known between Cirsium wrightii and C. vinaceum in the Sacramento Mountains of New Mexico. I have observed hummingbird visits to the heads of both species, though C. wrightii shows none of the apparent adaptations to hummingbirds (P. L. Barlow-Irick 2002) that are seen in such taxa as C. occidentale var. candidissimum, C. andersonii, and C. arizonicum.

Selected References

None.

Lower Taxa

None.

"fine" is not a number."wide" is not a number.

... more about "Cirsium wrightii"
short-tailed +
spineless +  and twisted +
dentate +, entire +  and spine-tipped +
erect +  and spreading +
innermost +
scarious +
0.2 cm2 mm <br />0.002 m <br /> (?) +
paniculiform +
indeterminate +  and determinate +
David J. Keil +
A. Gray +
decurrent +
Asteraceae tribe Cynareae +
compound +  and simple +
10 cm100 mm <br />0.1 m <br /> (60 cm600 mm <br />0.6 m <br />) +
irregularly dentate or;shallowly deeply pinnatifid +
5cm;20cm +
10-nerved or 20-nerved +  and rugose +
tawny +  and white +
Wright’s marsh thistle +
actinomorphic +
white +  and pink-purple +
1.9 cm19 mm <br />0.019 m <br /> (2.1 cm21 mm <br />0.021 m <br />) +
compressed +  and ovoid +
fertile +  and bisexual +
elliptic +  and linear to narrowly +
lobed +, dentate +  and bractlike +
Ariz. +, N.Mex. +, Tex. +, Mexico (Chihuahua) +  and Mexico (Sonora) +
1100–2600 m +
glabrescent +  and arachnoid +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Springs, seeps, marshes, stream banks, often in alkaline soil +
indeterminate +
each +  and sessile +
1 cm10 mm <br />0.01 m <br /> (2 cm20 mm <br />0.02 m <br />) +
glabrate +  and arachnoid +
ovoid;hemispheric +
1 cm10 mm <br />0.01 m <br /> (2 cm20 mm <br />0.02 m <br />) +
sessile +  and petiolate +
cauline +  and basal +
bristle-tipped +
lobed +, toothed +, obtuse +  and acute +
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
entire +  and dentate +
usually lobed +  and dissected +
2-carpellate +
persistent +
1.5 cm15 mm <br />0.015 m <br /> (1.6 cm16 mm <br />0.016 m <br />) +
1 cm10 mm <br />0.01 m <br /> (15 cm150 mm <br />0.15 m <br />) +
Flowering summer–fall (Aug–Oct). +
middle +  and outer +
weakly to strongly +
papillate +  and smooth +
Smithsonian Contr. Knowl. +
bearing subulate enations +, hairy +  and bristly +
flat;convex +
glutinous +
tawny;white +
setiform +  and plumose +
exalbuminous +
subequal +
1 cm10 mm <br />0.01 m <br /> (?) +
spiny-winged +, simple +  and branched +
appendaged +  and truncate +
dilated +  and swollen +
enlarged +
0.2 cm2 mm <br />0.002 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
Compositae +
Cirsium wrightii +
species +
cylindric +
expanded +
0.4 cm4 mm <br />0.004 m <br /> (0.45 cm4.5 mm <br />0.0045 m <br />) +
bristly-dentate to coarsely +
slender +
0.9 cm9 mm <br />0.009 m <br /> (1 cm10 mm <br />0.01 m <br />) +
perennial +  and biennial +
100 cm1,000 mm <br />1 m <br /> (300 cm3,000 mm <br />3 m <br />) +
tree +, vine +, shrub +  and subshrub +