Li Fertile glume and pale cartilaginous, coriaceous or papery; empty glumes more delicate, usually herbaceous, the lowest usually smallest.
The form of the flowering glume is very various, this organ being plastic and extensively modified in different genera.
Within these are six stamens, a hairy ovary surmounted by two feathery styles which ripens into the fruit (grain), and which is invested by the husk formed by the persistent glume and pale.
A Fertile glume and pale hyaline; empty glumes thick, membranous to coriaceous or cartilaginous, the lowest the largest.
In the closely allied genus Digitaria, which is sometimes regarded as a section of Panicum, the lowest barren glume is reduced to a point; D.
In Stipa, species of Avena, Heteropogon and others the base of the glume forms a sharp point which will easily penetrate the ground; above the point are short stiff upwardly pointing hairs which oppose its withdrawal.
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 flowering glume has generally a more or less boat-shaped form, is of firm consistence, and possesses a well-marked central midrib and frequently several lateral ones.
One-flowered spikelets may fall as a whole (as in the tribes Paniceae and Andrepogoneae), or the axis is jointed above the barren glumes so that only the flowering glume and pale fall with the fruit.
In many-flowered spikelets the rachilla is often jointed and breaks into as many pieces as there are fruits, each piece bearing a glume and pale.