Scientific NameDichanthelium clandestinum
Other Common Names:
Synonyms (former Scientific Names):
A perennial, warm season grass
Leaves are one-half to one and one-quarter inches wide and four to eight inches long. In autumn, culms form a very leafy rosette, four to six inches in height.
The midsummer growth normally reaches a height of one to three feet. The leaf sheath and stem are hairy. Deertongue lodges over winter and forms a mat of vegetative cover. Some of the stems break off and are carried away by wind or water. Much of the seed is retained in the leaf sheaths of the old stems. The wide leaves and prostrate growth habit of deer-tongue grass make it fairly easy to distinguish from most other grass weeds. This weed may be confused with Jointhead Arthraxon (Arthraxon hispidus), but has a panicled seedhead unlike the spikelets of jointhead arthraxon. The leaves of deer-tongue grass are generally much longer than those of jointhead arthraxon, and the stems of deer-tongue grass do not root at the nodes like those of jointhead arthraxon. Deer-tongue grass may also be confused with common or Asiatic dayflower (Commelina communis), which also has broad grass-like leaves and a prostrate growth habit. The two can be distinguished by the presence of a distinct ligule on deer-tongue grass, which is not present on common or Asiatic dayflower.
Flower Seed Head
A panicle that is typically 3 1/2 to 5 1/2 inches long and 2 1/2 to 3 1/2 inches broad.
Deertongue produces short, strong rhizomes. Two seed crops are produced annually: an early crop on an open terminal panicle and a later crop in a panicle enclosed in the swollen leaf sheath. The second crop, produced in the enclosed panicle, produces an abundance of seed. Deertongue has about 400,000 seeds per pound.
The natural distribution is Nova Scotia, Quebec, and Maine to Kansas, south to northern Florida and Texas. Deertongue is widely scattered throughout this area volunteering onto denuded sites. It grows well on non-cultivated soil. Because of its tolerance to low pH, high concentrations of aluminum, and droughty infertile conditions, it is commonly found to volunteer on such sites.
Leaf Hair on Upper Surface
rolled in bud
Mature Leaf Width
6 to 15 mm,
more than 15 mm
less than 1 mm,