Vol. 15—1961 - NorthEastern Weed Science Society

In a few grasses with smooth sheaths we find a ring of hairs
at the node. In at least one other with a very hairy sheath
we find a narrow, sticky ring just below the node that is
completely without hairs.
Moving now to the area where the blade is attached to the
sheath, we find in many grasses claw-like projections extending
from the base of the blade and more or less wrapping around the
stem or emerging bud-shoot. The projections are called auricles
and they may be quite small and slender or rather large and
prominent. In a few grasses careful examination of the auricles
with a magnifier will reveal that they are hairy.
At the base of the blade or the top of the sheath and behind
the stem or emerging shoot we nearly always find a projection
called the ligule. I say "nearly always" because it
is absent in the genus that includes barnyard grass and
Japanese millet. Ligules are of CWotypes, a thin whitish
membrane or a fringe of hairs, and may vary in length from
.2 Mm. or less to 8.0 Mm. or more. The membranous ligules may
vary in shape from those that are flattened across the top or
truncate, to those that generally have a decided notch on one
or both sides or in the center, or to those that rise to a sharp
acute or acuminate point in the center. The margins of most of
these membranes are entire or without divisions, lobes or teeth.
However some of them have a saw-toothed edge and in some the
edge or margin ends in fine hairs and is said to be ciliate.
In a few grasses we find that the back of this membrane is
covered with very fine hairs. The ligules that are a fringe
of hairs have less variations than the membranous ones. In
some grasses we find that the ligule is made up of a fringe of
short hairs with some scattered hairs that are very much
longer. These long hairs may be across the entire width of
the ligule or just on the sides. In other grasses we find that
the hairs are fused together at the base so that the lower part
appears to be membranous. In these cases the question could be
raised as to the dividing line becween a ligule that is a fringe
of hairs fused at the base and a membranous ligule that is
ciliate. My division is this -- if the fused or membranous
portion is shorter than the hairs, it is called a fringe of
hairs fused at base; if the fringe of hairs is shorter than the
membrane, it is a membranous ligule that is ciliate.