Angiosperms: Monocotyledons

Poaceae
Grass Family

• Notes:

  Species of Dichanthelium (all formerly placed within the genus Panicum), known as the rosette panic grasses, are very similar in general structure. Several species in this group are found regularly on Iowa prairies. We have chosen to consider four of the most common species (one with two varieties) to illustrate the group. The rosette panicums have proven to be very difficult to separate satisfactorily into discrete species. If you are interested in studying the group further, consult Pohl’s “The Grasses of Iowa” or another grass key covering the Midwest.

  The rosette panic grasses are short, not over 2’ tall. They bloom in late spring on flower stalks at the tip of the plant. The florets open and shed pollen but seldom set seeds. In early summer additional flower stalks are produced on branches at the middle of the stem. In this second blooming the florets do not open, but they do set seeds without the aid of pollination. During the summer many leaves are produced, but the plant does not grow much taller, resulting in a very bushy plant.

  The following guide can be used to identify the four species (one with two varieties) treated here:
  If the ligule is longer than 1/8”
  Dichanthelium acuminatum var. implicatum
  If the ligule is missing or shorter than 1/8”
  and the leaf blade is smooth above and below or with only a few scattered hairs
  Dichanthelium oligosanthes var. scribnerianum
  and the leaf blade is hairy
  only stiff-hairy below
  Dichanthelium linearifolium
  hairy both above and below
  and the spikelets are about 1/16” long
  Dichanthelium oligosanthes var. wilcoxianum
  and the spikelets are about 1/8” long
  Dichanthelium leibergii