Arctium tomentosum

Miller

Gard. Dict. ed. 8, Arctium no. 3. 1768.

Common names: Woolly burdock bardane tomenteuse
Introduced
Treatment appears in FNA Volume 19. Treatment on page 169. Mentioned on page 170.

Plants to 250 cm. Basal leaves: petioles hollow or solid, 10–15 cm, glandular-hairy; blades 30–40 × 16–28 cm, coarsely dentate to subentire, abaxially white-tomentose, adaxially green, sparsely short-hairy. Heads usually in corymbiform clusters, long-pedunculate. Peduncles 1.5–12 cm. Involucres 15–25 mm diam., densely cobwebby (rarely glabrate). Phyllaries linear to linear-lanceolate, inner usually purplish, margins with minute spreading or reflexed glandular-hairs. Florets 30+; corollas rose-purple, (occasionally white), 9–13 mm, limb minutely glandular. Cypselae light-brown, 5–8 mm; pappus bristles 1–3 mm. 2n = 36.


Phenology: Flowering summer–early fall (Jul–Oct).
Habitat: Waste places, roadsides, fields, forest clearings
Elevation: 0–1600 m

Distribution

V19-185-distribution-map.gif

Introduced; Alta., Man., N.B., Nfld. and Labr. (Nfld.), N.S., Ont., P.E.I., Que., Sask., Colo., Conn., Maine, Mass., Minn., Mo., N.H., N.Dak., Ohio, S.Dak., Vt., Eurasia

Discussion

Arctium tomentosum has been reported from Illinois, Iowa, Maryland, New Jersey, Oregon, Pennsylvania, South Carolina, and Wisconsin; I have not seen specimens.The involucres of Arctium tomentosum are usually very densely cobwebby.

Exceptional forms of A. tomentosum have nearly glabrous involucres. Forms of A. minus with especially cobwebby involucres have been misidentified as A. tomentosum; they lack the corymbiform capitulescence and glandular corollas of the latter.

Selected References

None.

Lower Taxa

None.

"fine" is not a number.

... more about "Arctium tomentosum"
scarious +
obtuse +  and acute +
racemiform +  and paniculiform or corymbiform +
indeterminate +  and determinate +
David J. Keil +
Miller +
decurrent +
Asteraceae tribe Cynareae +
compound +  and simple +
30 cm300 mm <br />0.3 m <br /> (40 cm400 mm <br />0.4 m <br />) +
short-hairy +  and white-tomentose +
coarsely dentate;subentire +
16cm;28cm +
10-nerved or 20-nerved +  and rugose +
Woolly burdock +  and bardane tomenteuse +
actinomorphic +
glandular-puberulent +  and glabrous +
0.9 cm9 mm <br />0.009 m <br /> (1.3 cm13 mm <br />0.013 m <br />) +
compressed +  and obovoid +
fertile +  and bisexual +
Alta. +, Man. +, N.B. +, Nfld. and Labr. (Nfld.) +, N.S. +, Ont. +, P.E.I. +, Que. +, Sask. +, Colo. +, Conn. +, Maine +, Mass. +, Minn. +, Mo. +, N.H. +, N.Dak. +, Ohio +, S.Dak. +, Vt. +  and Eurasia +
0–1600 m +
tomentose +  and resin-gland-dotted +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
reflexed +, spreading +  and minute +
Waste places, roadsides, fields, forest clearings +
long-pedunculate +
in corymbiform , paniculiform or racemiform , arrays +  and singly +
indeterminate +
each +  and sessile +
erect +  and ascending +
1.5 cm15 mm <br />0.015 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
spheric;ovoid +
long-petiolate +
cauline +  and basal +
smaller +
triangular +
usually lobed +  and dissected +
2-carpellate +
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
persistent +
1.5 cm15 mm <br />0.015 m <br /> (12 cm120 mm <br />0.12 m <br />) +
solid +  and hollow +
glandular-hairy +
10 cm100 mm <br />0.1 m <br /> (15 cm150 mm <br />0.15 m <br />) +
Flowering summer–early fall (Jul–Oct). +
papillate +  and smooth +
distinct +  and fused +
hairy-ringed +
Gard. Dict. ed. +
bearing subulate enations +, hairy +  and bristly +
flat;convex +
subulate +
exalbuminous +
Introduced +
appendaged +  and truncate +
dilated +  and swollen +
enlarged +
Compositae +
Arctium tomentosum +
species +
campanulate +
elongate +
perennial +  and biennial +
50 cm500 mm <br />0.5 m <br /> (300 cm3,000 mm <br />3 m <br />) +