Fig. 016. Spikelet of the Oat (Avena sativa).

Gallery: 
Fig. 16. Spikelet of the Oat (Avena sativa).

gl. Glumes.
ps. fs. Paleae or pales.
a. Awn.
pl. An abortive flower.

This image is from Starch in Sayre's Manual of Organic Materia Medica and Pharmacognosy, 1917.