Recognize the problem
Family:
Asteraceae (daisy family)
Common
names: upright starbur, bristly starbur, goat's head, star burr, Texas
cockspur, upright starbur.
Chichewa: Nsakambwa,
Kamphondo.
Annual
herbaceous plant with an erect and rounded stem (30-60 (-90) cm tall),
initially green turning brown, dichotomous branching with a branched and
shallow taproot, covered in stiff hairs, sometimes sticky.
Leaves:
Green, hairy, glands on lower surface, egg-shaped or oval [(2-) 8 (-12.5) cm
long and 1-3 cm wide], margins wavy, slightly lobed, or irregularly toothed,
in opposite pairs on stem, without or with very short leaf stalks with a
winged base up to 10 mm long.
Flowers:
Pale yellow-green (6 mm wide), singly on short stalks (1-15 mm long) in the
forks of leaves, sometimes also in the forks of branches near the top of the
plant.
Fruits:
Small, dry, one-seeded, yellowish brown to dark brown star-shaped burr (10-18
mm wide), covered in many short, stiff, hooked spines, with two longer spines
(3-4 mm long) at end, held in star-shaped clusters of 7-8.
Background
Origin:
Latin America.
Introduction:
Accidentally as a contaminant of seed and commodities.
Habitat:
Mainly tropical and sub-tropical regions; on a wide range of soils, but
particularly common on very light sandy soils.
Spread:
As a contaminant of seed and commodities, on vehicles and animal fur.
Invades:
Crop fields, plantations, fallow lands and pastures, roadsides, disturbed
areas, wastelands, urban open space, and gardens.
Impacts:
This weed can reduce yields because it competes with crops for water and
nutrients. Groundnut seed yield can be reduced by as much as 50%. Losses in
soja beans were lower when the weed appeared 11-22 days after planting of the
crop. It is an alternative host for many crop pests and diseases such as tomato
leaf curl virus, tobacco leaf curl virus and groundnut ringspot virus, the
causal agent of spotted wilt in tobacco. Although the this weed is generally
avoided by livestock, it can be toxic to animals if consumed on a daily basis
over long periods of time. The spiny burrs can lodge in the wool of sheep,
reducing the quality, and penetrate the hooves of livestock, often resulting
in infection and subsequent lameness.
Acanthospermum hispidium has been declared as a noxious weed throughout the whole of Malawi in
terms of section 15 of Act G.N. 20/1957.
