Cirsium discolor

(Muhlenberg ex Willdenow) Sprengel

Syst. Veg. 3: 373. 1826.

Common names: Field thistle chardon discolore
IllustratedEndemic
Basionym: Cnicus discolor Muhlenberg ex Willdenow Sp. Pl. 3: 1670. 1803
Synonyms: Carduus discolor (Muhlenberg ex Willdenow) Nuttall
Treatment appears in FNA Volume 19. Treatment on page 112. Mentioned on page 98, 99, 113.

Biennials or sometimes perennials, 80–200 cm; taproots and often cluster of coarse fibrous-roots, roots without tuberlike enlargements. Stems single, erect, villous with septate trichomes, sometimes ± glabrate, distally ± tomentose; branches few–many, ascending. Leaves: blades oblanceolate to elliptic or ovate, 10–25 (–50) × 1–13 (–25) cm, usually deeply divided more than halfway to midveins, proximal sometimes undivided, lobes linear-lanceolate, margins revolute, ascending, entire or spinulose to remotely few toothed or sharply lobed, main spines 1–5 mm, abaxial faces white-tomentose, adaxial faces green, villous with septate trichomes or glabrate; basal usually absent at flowering, winged-petiolate, bases tapered; principal cauline well distributed, gradually reduced, bases narrowed, sometimes weakly clasping, not decurrent; distal cauline well developed. Heads 1–many in corymbiform or paniculiform arrays. Peduncles 0–5 cm (not overtopped by crowded distal cauline leaves). Involucres ovoid to broadly cylindric or campanulate, 2–3.5 (–4) × 1.5–3 cm, thinly arachnoid. Phyllaries in 10–12 series, strongly imbricate, greenish with subapical darker central zone, ovate (outer) to lanceolate (inner), abaxial faces with narrow glutinous ridge, outer and middle bodies appressed, margins entire, spines abruptly spreading to deflexed, slender, 3–9 mm; spines slender, 3–9 mm; apices of inner phyllaries spreading, narrow, flattened, finely serrulate. Corollas pink to purple (white), 25–32 mm, tubes 12–16 mm, throats 7–10 mm, (noticeably wider than tubes), lobes 6–9 mm; style tips 4–6 mm. Cypselae tan to brownish, 4–5 mm, apical collars straw-colored, 0.5–75 mm; pappi 18–25 mm. 2n = 20, 21, 22.


Phenology: Flowering summer–fall (Jun–Oct).
Habitat: Tallgrass prairies, deciduous woodlands, forest openings, disturbed sites, often in damp soil
Elevation: 5–800 m

Distribution

V19-58-distribution-map.gif

Man., Ont., Que., Sask., Ala., Ark., Conn., Del., D.C., Ga., Ill., Ind., Iowa, Kans., Ky., La., Maine, Md., Mass., Mich., Minn., Mo., Nebr., N.H., N.Y., N.C., Ohio, Pa., R.I., S.C., S.Dak., Tenn., Vt., Va., W.Va., Wis.

Discussion

Cirsium discolor is widespread in eastern North America from the prairies of southeastern Saskatchewan, western Minnesota, and Iowa south to northern Louisiana and east across southern Canada to the New England states and the southern Appalachians. It hybridizes with both C. altissimum (discussed thereunder) and C. muticum (G. B. Ownbey 1951b, 1964; W. L. Bloom 1977). Meiosis in first-generation hybrids between C. discolor and C. muticum is usually irregular (Bloom) and most pollen grains are infertile (Ownbey 1951b; Bloom). The presence of a small number of viable cypselae in heads of putative F1 hybrids (Ownbey 1951b) indicates that some F2 hybrids or backcrosses are formed.

Selected References

None.

Lower Taxa

None.

"fine" is not a number.

... more about "Cirsium discolor"
22 +, 21 +  and 20 +
white-tomentose +
glabrate +  and villous +
short-tailed +
spineless +  and twisted +
dentate +, entire +  and spine-tipped +
erect +  and spreading +
innermost +
scarious +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (7.5 cm75 mm <br />0.075 m <br />) +
paniculiform +  and corymbiform +
indeterminate +  and determinate +
David J. Keil +
(Muhlenberg ex Willdenow) Sprengel +
winged-petiolate +
not decurrent +, narrowed +  and tapered +
Cnicus discolor +
compound +  and simple +
25 cm250 mm <br />0.25 m <br /> (50 cm500 mm <br />0.5 m <br />) +
13 cm130 mm <br />0.13 m <br /> (25 cm250 mm <br />0.25 m <br />) +
10 cm100 mm <br />0.1 m <br /> (25 cm250 mm <br />0.25 m <br />) +
divided;oblanceolate;elliptic or ovate +
1cm;13cm +
10-nerved or 20-nerved +  and rugose +
tawny +  and white +
? (?) +  and ? (?) +
Field thistle +  and chardon discolore +
actinomorphic +
pink +  and purple +
2.5 cm25 mm <br />0.025 m <br /> (3.2 cm32 mm <br />0.032 m <br />) +
tan +  and brownish +
compressed +  and ovoid +
fertile +  and bisexual +
Man. +, Ont. +, Que. +, Sask. +, Ala. +, Ark. +, Conn. +, Del. +, D.C. +, Ga. +, Ill. +, Ind. +, Iowa +, Kans. +, Ky. +, La. +, Maine +, Md. +, Mass. +, Mich. +, Minn. +, Mo. +, Nebr. +, N.H. +, N.Y. +, N.C. +, Ohio +, Pa. +, R.I. +, S.C. +, S.Dak. +, Tenn. +, Vt. +, Va. +, W.Va. +  and Wis. +
5–800 m +
gray-canescent +  and glabrous +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Tallgrass prairies, deciduous woodlands, forest openings, disturbed sites, often in damp soil +
indeterminate +
each +  and sessile +
3.5 cm35 mm <br />0.035 m <br /> (4 cm40 mm <br />0.04 m <br />) +
2 cm20 mm <br />0.02 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
ovoid;broadly cylindric or 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 +
linear-lanceolate +
0.1 cm1 mm <br />0.001 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
entire +  and spinulose to remotely few toothed or sharply lobed +
usually lobed +  and dissected +
2-carpellate +
persistent +
1.8 cm18 mm <br />0.018 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
0 cm0 mm <br />0 m <br /> (5 cm50 mm <br />0.05 m <br />) +
Flowering summer–fall (Jun–Oct). +
middle +  and outer +
weakly to strongly +
papillate +  and smooth +
bearing subulate enations +, hairy +  and bristly +
flat;convex +
glutinous +
tawny;white +
setiform +  and plumose +
exalbuminous +
subequal +
Illustrated +  and Endemic +
abruptly spreading +  and deflexed +
0.3 cm3 mm <br />0.003 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
spiny-winged +, simple +  and branched +
appendaged +  and truncate +
dilated +  and swollen +
enlarged +
0.4 cm4 mm <br />0.004 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
Carduus discolor +
Cirsium discolor +
species +
cylindric +
expanded +
0.7 cm7 mm <br />0.007 m <br /> (1 cm10 mm <br />0.01 m <br />) +
bristly-dentate to coarsely +
slender +
1.2 cm12 mm <br />0.012 m <br /> (1.6 cm16 mm <br />0.016 m <br />) +
perennial +  and biennial +
80 cm800 mm <br />0.8 m <br /> (200 cm2,000 mm <br />2 m <br />) +
tree +, vine +, shrub +  and subshrub +