=11.= HORDEÆ. Spikes compound; spikelets sessile in the notches of a toothed axis. =A.= Spikelets solitary.--_Triticum_ (Wheat, Fig. 287) has in each tooth of the main axis, a several-flowered spikelet which turns its _flat side_ towards the central axis. The cultivated species (true Wheat) are 1-2-annual, the wild ones (_T. repens_, Couch, also as an independent genus, _Agropyrum_) are perennial, with creeping rhizome and lanceolate glumes.--_Lolium_ (Rye-grass) has in each tooth of the main axis a many-flowered, compressed spikelet, which is placed _edgewise_ towards it and (with the exception of _L. perenne_) has only one outwardly-turned glume (_L. temulentum_ has a rudiment of the inwardly-turned lower glume); the terminal spikelet has two glumes.--_Secale_ (Rye). A two-flowered spikelet in each tooth; small, lanceolate, acuminate glumes. _Nardus_ and _Lepturus_ have very narrow spikes, the former with unilateral spikelets. =B.= In each notch of the axis 2 or more spikelets are placed close together.--_Hordeum_ (Barley). In each tooth three 1-flowered spikelets. _H. hexastichum_ (6-rowed Barley), has 6 rows of fruits, since all the spikelets are fertile, and _H. distichum_ (2-rowed Barley) 2 rows, since the lateral spikelets are (♂, and barren (p. 292).--_Elymus_ has 2–6 many-flowered spikelets in each joint of the main axis. _Ægilops_ has awns upon the glumes. DISTRIBUTION. 315 genera with 3,500 species. The order is distributed over the whole world, and as regards number of individuals is perhaps the richest. In the Tropics, large, broad-leaved, tree-like forms are found (_Bambuseæ_, _Olyreæ_, _Andropogoneæ_, etc.; in S. Europe, _Arundo donax_); in England, next to the Compositæ, it is the order most rich in species (about 134).--The origin of some of the cultivated Grasses is lost in obscurity. The Maize, no doubt, was indigenous to America, where its nearest relatives are found, and where it has also been discovered in ancient Indian graves; Durra or Guinea-corn, Millet and Sugar-cane are South Asiatic plants, and our own cereals no doubt have sprung primarily from Western Asia and South-Eastern Europe (Barley from Armenia and Persia, where a very closely related wild species is found; Wheat from the same districts; Rye from the perennial species _S. montanum_). _Panicum altissimum_ and Rice have come from Africa.