Ontario Weeds: Smooth crab
Table of Contents
- Other Names
- General Description
- Stems and Roots
- Flowers and Fruit
- Similar Species
- Related Links
Name: Smooth crab grass, Digitaria
ischaemum (Schreb) Muhl.
Other Names: DIGIS, disitaire astringente,
Finger grass, Small crab grass, digitaire glabre
Family: Grass Family (Gramineae)
General Description: Before heading
out, both Smooth crab grass and Large crab grass are distinguished
by their tapered leaf blades, their split sheaths with hairless
margins, their membranous ligueles with no auricles, their more
or less hairy lower leaf sheaths adn their either hairy or smooth
blades. After heading out, the slender finger-like spikes are distinctive.
Photos and Pictures
Smooth crab grass. Viewed from above.
Stem and leaf-base characteristics of a typical
Stems & Roots: Smooth hairless
leaf blades, and upper leaf sheaths usually smooth and hairless,
but the lower ones may be womewhat hairy; ligule also membranous
but usually a bit longer (2-3mm, 1/12 - 1/8in.), nad there is a
tuft of long hair on either side of the leaf-base of the lower leaves.
Flowers & Fruit: No auricales;
inflorescence almost identical to that of Large crab grass but usually
with only a single whorl of spikes at the end of the stem. Flowers
from August to September.
Habitat: Both kinds of crab grass
are common in southern Ontario but they also occur sporadically
in nothern and northwestern Ontario. Both occur in row crops and
other fields, waste places, gardens and lawns.
Similar Species: Very similar to Large
crab grass but is usually shorter.
... on general Weed
... on weed identification, order OMAFRA
Publication 505: Ontario Weeds
... on weed control, order OMAFRA
Publication 75: Guide To Weed Control
to the Ontario Weeds Gallery |