The awn is also of use in burying the fruit in the soil.
The midrib in a large proportion of genera extends into an appendage termed the awn (fig.
Pointed, awn twisted at base.
The repeated twisting and untwisting, especially when the upper part of the awn has become fixed in the earth or caught in surrounding vegetation, drives the point deeper and deeper into the ground.
Fertile glumes generally shorter than the empty glumes, usually with a bent awn on the back.
The awn which is frequently borne on the flowering glume is also a very efficient means of distribution, catching into fur of animals or plumage of birds, or as often in Stipa (fig.
The awn may be either terminal or may come off from the back of the flowering glume, and Duval Jouve's observations have shown that it represents the blade of the leaf of which the portion of the flowering glume below its origin is the sheath; the twisted part (so often suppressed) corresponds with the petiole, and the portion of the glume extending beyond the origin of the awn (very long in some species, e.g.
When terminal the awn has three fibro-vascular bundles, when dorsal only one; it is covered with stomate-bearing epidermis.
I), the flowering glume having its dorsal rib prolonged into an awn (fig.