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Xanthium strumarium L.Xanthium strumarium var. canadenseAsteraceae (Sunflower Family)Native, WorldwideSpiny Cocklebur |
September Photo
Plant Characteristics:
Coarse branching annual 5-15 dm. high; lf blades 3-12 cm. long and
equally wide, on slender petioles as long, deltoid-ovate, +/- cordate at base,
dentate or serrate and somewhat lobed, thickish, scabridulous; staminate heads
borne above the female in terminal and axillary clusters, many-fld.; burs
narrowly to broadly ovoid, greenish- or yellowish-brown, mostly 2-3.5 cm. long,
the +/- crowded often very stout prickles hispid with stout gland-tipped hairs
in lower half, the beaks short and very stout, with short incurved tips.
Habitat:
The common form of this cosmopolitan weed in Calif., often abundant in
moist valley floors throughout. July-Oct.
Name:
Xanthium comes from the Greek
word meaning "yellow" and was the ancient name of a plant used to dye
hair. (Dale 76).
Latin, strumosus, swollen. Canadense,
of Canada, where the first species were found.
(John Johnson).
General: Common in the study area.
Photographed near the Delhi Ditch and on the Santa Ana Heights Flats.
(my comments). The
two seeds protected in each bur retain their vitality for many years.
The burs are obnoxious in pastures where they become entangled in manes
and tails and reduce the value of wool on sheep. Seedlings and seeds are poisonous to animals.
(Dale 76). Xanthium,
cocklebur is a good example of a plant in which only a certain part-the seed- is
toxic. Hydroquinone is the
poisonous substance in cocklebur and so far as is known, it is not found in any
other plant. Its major effects are
severe upset of the digestive system accompanied by or followed by general
weakness, prostration and paralysis. The
first leaves of seedlings are also poisonous.
(Kingsbury 67). Possibly
only three species, X. strumarium var.
canadense and X. spinosum
being of doubtful origin. (Munz, Flora
So. Calif. 241).
There has been much discussion of the classification, distribution and
origins of the different populations of cockleburs.
Some people insisted they were all imported, but I believe it has been
shown that some were here originally along with the Indians.
(John Johnson). Xanthium
species have been known to cause hay fever, asthma, and dermatitis.
(Fuller
Text Ref:
Hickman, Ed. 360; Munz, Calif. Flora
1105; Munz, Flora So. Calif. 241; Roberts 14.
Photo Ref:
June 1 83 # 1; June 6 83 # 27; Sept 1 83 # 12; Nov-Dec 89 # 17; Sept 95 #
8,9.
Identity: by R. De Ruff.
First Found: June 1983.
Computer Ref:
Plant Data 198.
No plant specimen.
Last edit 5/17/05.
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