Vascular Plants of North Carolina
Account for Small-fruited Witchgrass - Dichanthelium microcarpon   (Muhlenberg ex Elliott) Mohlenbrock
Members of Dichanthelium with account distribution info or public map:
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Section 5 » Family Poaceae
Author(Muhlenberg ex Elliott) Mohlenbrock
DistributionThroughout the state, with small gaps, except rare on the Outer Banks (Roanoke Island only).

MA to MI, south to FL and TX.
AbundanceFrequent to common throughout, except rare on the Outer Banks. The website editors suggest a State rank of S5?, and it almost certainly is a straight S5.
HabitatA wide variety of moist to seasonally wet soil habitats, from wet savannas to streamhead ecotones, montane seepage bogs, openings in swamp forests, streamsides, moist clearcuts.
PhenologyFlowering and fruiting May-October.
IdentificationUntil recently, most authors treated it as a variety or subspecies of D. dichotomum. It differs from var. dichotomun in having smaller spikelets (1.4-1.9 mm long vs. 1.8-2.3 mm long in D. dichotomum) and having wider vernal leaf blades (7-15 mm wide vs. 3-8 mm wide in that species). It is easily confused with D. dichotomum var. nitidum, but the spikelets are shorter (1.4-1.9 mm long vs. 1.7-2.2 mm long in that form) and a shorter first glume.
Taxonomic CommentsA synonym is D. dichotomum var. ramulosum; or also named as subspecies ramulosum.

A note about Dichanthelium: This genus is not impossible to identify to species! But it takes applied effort over a period of time in order to learn the various species and what their morphological limits are. We strongly recommend that you read the introduction to the treatment in Weakley (2018), written by Richard LeBlond. LeBlond has made order out of near chaos, and his keys work very well for our plants. Most Dichanthelium taxa ("Dichs") do not grow everywhere indiscrimminately, but prefer certain well-defined habitats. Note that most species produce flowers/fruits twice a year -- a vernal period and an autumnal period -- and that measurements of spikelets and achenes are taken from vernal plants. Some species also have a third, or summer, period. In the vernal period there is a single inflorescence at the tip of the stem. In the autumnal period, plants produce elongate branches with bunched (congested) leaves and so look quite different from vernal plants. Inflorescences are produced in leaf axils as well as at the tips of branches. NOTE: Older texts had these species essentially all within the very large genus Panicum. "Dich" species are typically named as "Witchgrass" and Panicum species named as "Panicgrass".
Other Common Name(s)Small-fruited Panicgrass
State Rank[S5?]
Global RankGNR
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