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Arctium macropterum

Interesting Facts

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Description

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Family Compositae

The largest family of flowering plants , the Compositae (Asteraceae), comprising about 1,100 genera and more than 20,000 species and characterized by many small flowers arranged in a head looking like a single flower and subtended by an involucre of bracts. A head may consist of both ray flowers and disk flowers, as in the sunflower, of disk flowers only, as in the burdock, or of ray flowers only, as in the dandelion.

Genus Arctium

Biennials or (monocarpic ) perennials, 50-300 cm; herbage not spiny . Stems erect , openly branched, branches ascending . Leaves basal and cauline; long-petiolate; gradually smaller distally; blade margins entire or dentate (pinnately lobed or dissected ), faces abaxially resin-gland-dotted, adaxially often tomentose . Heads discoid , in leafy-bracted racemiform to paniculiform or corymbiform arrays. ( Peduncles 0 or 1-9 cm.) Involucres spheric to ovoid . Phyllaries many in 9-17 series, outer and mid narrowly linear . bases appressed , margins entire. apices stiffly radiating, hooked-spiny tipped, inner linear, ascending or erect, straight tipped. Receptacles ± flat, epaleate, bearing subulate scales . Florets (5-) 20-40+; corollas pink to ± purple, glabrous or glandular-puberulent, tubes elongate . throats campanulate . lobes narrowly triangular, ± equal; anther bases tailed , apical appendages ovate , obtuse to acute; style branches: fused portions distally hairy-ringed, distinct portions oblong , acute or obtuse . Cypselae obovoid . ± compressed , rough or ribbed , glabrous, attachment scars basal; pappi falling, of many bristles in 2-4 series . x = 18.

Species 10: introduced ; Eurasia , n Africa, widely introduced worldwide.

At maturity the dry heads of Arctium species are readily caducous with the enclosed cypselae, and the hooked phyllary tips cling easily to fur or fabrics. Animal dispersal is a major factor in the spread of burdock species across North America. The burs are a major problem when they become entangled in the wool of sheep and fur of dogs and other animals.

Published chromosome reports for Arctium other than n = 18 are probably in error because of difficulty in interpretation of somatic chromosomes (R. J. Moore and C. Frankton 1974).[1]

Taxonomy

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Similar Species

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Members of the genus Arctium

ZipcodeZoo has pages for 16 species, subspecies, varieties, forms, and cultivars in this genus:

A. lappa (Beggars Buttons) · A. lappa majus (Edible Burdock) · A. lappa 'Chiko' (Beggars Buttons) · A. lappa 'Ha Gobo' (Edible Burdock) · A. lappa 'Shirohada' (Vegetable Burdock) · A. lappa 'Takinogawa' (Edible Burdock) · A. lappa 'Takinogawa Long' (Beggars Buttons) · A. lappa 'Watanabe Early' (Edible Burdock) · A. minus (Bardane) · A. mixtum (Burrdock) · A. nemorosum (Wood Burdock) · A. nothum (Burrdock) · A. tomentosum (Woolly Burdock) · A. vulgare (European Burdock) · A. x mixtum (Burrdock) · A. x nothum (Burrdock)

More Info

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Further Reading

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Notes

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Contributors

Identifiers

Footnotes

  1. David J. Keil "Arctium". in Flora of North America Vol. 19, 20 and 21 Page 28, 58, 83, 168, 169. Oxford University Press. Online at EFloras.org. [back]
Last Revised: 2012-07-19