Ligule
Definition
(a) A thin, non-green membranous outgrowth or row of hairs often found on the upper and inner side of the leaf blade where it joins the sheath. Occurs in many grasses and some sedges. <a href="drawings.php?drawingID=14">See drawing of parts of a grass plant.</a> (b) A flattened, strap-shaped part of the ray corolla in the Asteraceae Family.
Reference
drawings.php?drawingID=14