Carduus acanthoides subsp. acanthoides

Treatment appears in FNA Volume 19. Treatment on page 92.

Annuals or biennials, 30–200 (–400) cm. Stems openly branching, villous with curled, septate hairs to nearly glabrous, teeth of wings to 1.5 cm, wing spines to 8 mm. Leaves: basal 10–30 cm, tapering to winged petioles, margins spiny toothed to deeply 1–2×-pinnately divided; cauline sessile, gradually smaller; marginal spines to 5 mm; abaxial leaf faces glabrate except for long, curled, septate hairs along veins; adaxial faces sparsely hairy or glabrate. Heads borne singly or in corymbiform arrays of 2–5, sometimes also in upper axils, 18–25 mm. Peduncles spiny winged throughout, to 4 (–10) cm. Involucres hemispheric, 14–20 × 10–25 mm. Phyllaries linear to narrowly lanceolate, outer and middle with appressed bases 1–1.5 mm wide and appressed to spreading appendages 0.5–1 mm wide, distally glabrous or minutely ciliolate, spine tips 1–2 mm, the inner phyllaries with unarmed, straight or twisted tips. Corollas purple or ± white, 13–20 mm. Cypselae golden to brown, 2.5–3 mm; pappus bristles 11–13 mm. 2n = 22.


Phenology: Flowering summer–early fall (Jun–Oct).
Habitat: Aggressive weed of waste ground, pastures, roadsides, fields
Elevation: 0–3000 m

Distribution

V19-45-distribution-map.gif

Introduced; B.C., N.B., N.S., Ont., Que., Calif., Colo., Idaho, Ill., Iowa, Kans., Md., Mich., Minn., Mo., Mont., Nebr., N.J., N.Y., N.C., N.Dak., Pa., R.I., S.Dak., Vt., Va., W.Va., Wis., Wyo., Eurasia

Discussion

Carduus acanthoides has been reported as growing in Connecticut, Delaware, Kentucky, Massachusetts, Maine, Ohio, Oklahoma, Texas, and Washington; I have not seen specimens from those states. It was collected only once in New Brunswick in 1992.

Carduus acanthoides is a serious weed in pasturelands, where it displaces and suppresses growth of other plants and limits access of grazing animals to more palatable plants (A. M. Desrochers et al. 1988). It sometimes grows in dense stands.

Selected References

None.

Lower Taxa

None.

"fine" is not a number.

glabrate +  and hairy +
short-tailed +
ascending +  and spreading or reflexed +
scarious +
ciliolate +  and glabrous +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
indeterminate +  and determinate +
David J. Keil +
Linnaeus +
10 cm100 mm <br />0.1 m <br /> (30 cm300 mm <br />0.3 m <br />) +
decurrent +
1mm;1.5mm +
Asteraceae tribe Cynareae +
compound +  and simple +
10-nerved or 20-nerved +  and rugose +
actinomorphic +
white +  and purple +
1.3 cm13 mm <br />0.013 m <br /> (2 cm20 mm <br />0.02 m <br />) +
golden +  and brown +
compressed +  and ovoid +
fertile +  and bisexual +
B.C. +, N.B. +, N.S. +, Ont. +, Que. +, Calif. +, Colo. +, Idaho +, Ill. +, Iowa +, Kans. +, Md. +, Mich. +, Minn. +, Mo. +, Mont. +, Nebr. +, N.J. +, N.Y. +, N.C. +, N.Dak. +, Pa. +, R.I. +, S.Dak. +, Vt. +, Va. +, W.Va. +, Wis. +, Wyo. +  and Eurasia +
0–3000 m +
glabrous +  and hairy +
pistillate +, staminate +  and neuter +
several;many +
winged +  and beaked +
dispersed +
Aggressive weed of waste ground, pastures, roadsides, fields +
in corymbiform arrays +  and singly +
indeterminate +
1.8 cm18 mm <br />0.018 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
each +  and sessile +
1.4 cm14 mm <br />0.014 m <br /> (2 cm20 mm <br />0.02 m <br />) +
hemispheric +
1 cm10 mm <br />0.01 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
sessile +  and petiolate +
cauline +  and basal +
deltate +, usually narrowly triangular +  and more or less linear +
divided +  and toothed to deeply +
2-carpellate +
1.1 cm11 mm <br />0.011 m <br /> (1.3 cm13 mm <br />0.013 m <br />) +
persistent +
4 cm40 mm <br />0.04 m <br /> (10 cm100 mm <br />0.1 m <br />) +
0 cm0 mm <br />0 m <br /> (4 cm40 mm <br />0.04 m <br />) +
Flowering summer–early fall (Jun–Oct). +
appressed +  and spreading +
middle +  and outer +
papillate +  and smooth +
distinct +  and fused +
bearing subulate enations +, hairy +  and bristly +
flat;convex +
setiform +
exalbuminous +
Introduced +  and Illustrated +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
appendaged +  and truncate +
dilated +  and swollen +
enlarged +
Compositae +
Carduus acanthoides subsp. acanthoides +
Carduus acanthoides +
subspecies +
campanulate +
expanded +
twisted +  and unarmed +
straight +
0 cm0 mm <br />0 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
slender +
200 cm2,000 mm <br />2 m <br /> (400 cm4,000 mm <br />4 m <br />) +
biennial +  and annual +
glabrate +  and tomentose +
30 cm300 mm <br />0.3 m <br /> (200 cm2,000 mm <br />2 m <br />) +
tree +, vine +, shrub +  and subshrub +
13 +, 11 +, 10 +, 9 +  and 8 +