Biology Reference
In-Depth Information
Witchweed
A parasitic weed,
Striga asiatica
, new to the
western hemisphere, was reported from North
Carolina in 1956 and later from South Carolina,
although apparently it was first seen in the latter
state in 1951 following construction of a power
line across a farm. The plant is an obligate root
parasite of corn and crabgrass, perhaps other
plants. It is 2 to 15 inches high, foliage varying
from dark to light green, with linear leaves curv-
ing downward, tubular flowers with two-lipped
corolla, cardinal red on the upper surface with a
yellow eye, straw yellow on the lower surface.
The numerous brown seeds are very minute.
Witchweed is reported from other countries
on 63 plant species, 56 of them members of
the Gramineae (grains and grasses). Tests in the
United States with 77 non-gramineous hosts
found none parasitized by witchweed, but 45
species of our grasses and grains are susceptible
to this new pest. To help in eradication, report
suspicious weeds immediately to your county
agent or extension pathologist.
