CHAPTER XXIV 
TrisE XII. HORDE 
A SMALL tribe of about 25 genera in the temperate 
regions of both hemispheres. Spikelets 1- to several- 
flowered, sessile in spikes. The rachis is flattened or 
concave next to the spikelets, or in some genera it is 
hollowed out so that the spikelets are embedded or ‘in- 
closed. The spike is 1-sided in Nardus (of Eurasia), but 
symmetrical in all other genera. In Triticum and its 
allies there is 1 spikelet at each node of the rachis, and in 
Hordeum and its allies there are 2 or more. The spikelets 
are usually placed sidewise to the rachis but in Lolium 
and its allies they are placed edgewise. In these genera the 
outer glume is fully developed, but the inner (second) 
glume is reduced or wanting except in the terminal spikelet, 
where the glumes are equal. The rachis of the spike dis- 
articulates in Sitanion, Scribneria, Lepturus and a few 
species of Elymus and Agropyron. In some species of 
Elymus the glumes, except in the terminal spikelet, stand 
in front of the spikelet instead of at the 2 sides. According 
to some these 2 organs are the 2 portions of a single deeply 
cleft glume (Par. 153) or represent branchlets. In some 
species of Elymus and especially in Sitanion the glumes 
are very slender, extending into long awns. In Sitanion 
the glumes are commonly split into 2-several slender awns. 
The blades of this tribe usually bear on each side at the 
base an appendage or auricle. To this tribe belong our 
most important cereals. 
(235) 
