Virginia Tech Weed Identification Guide

Annual Jewgrass, Basketgrass, Mary's Grass, or Microstegium:

Microstegium vimineum var. imberbe

Weed Description:  Prostrate to erect summer annual grass that thrives in shaded areas.  This grass weed roots at the nodes and therefore may quickly spread into shaded areas like backyard lawns, ditches, roadsides, etc.
Leaves:  Rolled in the shoot, 3 to 10 mm wide, sparsely hairy on both surfaces.  Most leaves have a distinct white midvein, however a key identifying feature of this grass is that the midvein does not divide the leaves into equal halves.  For example, one side of the leaf separated by the midvein will be much larger than the other side of the leaf (shown in picture below).  Leaves have a very short (0.2 mm), ciliate membranous ligule and no auricles.
stiltgrass3-29.jpg (74606 bytes) Stems:  Round, often hairy at the top, and capable of rooting at the nodes (shown in picture above).
Roots:  A fibrous root system.

Flowers:  Seedhead composed of 1 to 6 terminal spike branches. 

mcgvm6-18b.jpg (129375 bytes)
japstilt9-24b.jpg (168324 bytes) Identifying Characteristics:  Leaf shape and habitat (shade-loving) are the primary features that help to distinguish this grass from other grasses.  Few, if any, grass weeds have a midvein that does not proportionally separate an individual leaf.