Glumales.] GRAMINACE^. Ill 



assume the appearance of trees. Some species of Bambusa are from 50 to 60 feet high. 

 2. The leaves of the tropical Gi'asses are broader, and approach more in form to those 

 of other families of plants. Of this the genus Paspalus affords many examples. 3. Sepa- 

 rate sexes are more frequent in the tropical Grasses. Zea, Sorghum, Andropogon, Ol^Ta, 

 Anthistiria, Isehsemum, ^gilops, and many other genera, which only occur in the torrid 

 zone, and are there found in perfection, are monoecious, or polygamous. Holcus is per- 

 haps tlie only extra-tropical genus with separate sexes. 4. The flowers are softer, more 

 downy, and elegant. 5. The extra-tropical Grasses, on the contrary, far surpass the 

 tropical in respect of the number of individuals. That compact grassy turf, which, 

 especially in the colder parts of the temperate zones, in spring and summer, composes 

 the green meadows and pastures, is almost entirely wanting in the torrid zone. The 

 Grasses there do not grow crowded together, but, Uke other plants, more dispersed. 

 Even in the southern parts of Europe, the assimilation to the warmer regions, in this 

 respect, is by no means inconsiderable. Arundo donax, by its height, reminds us of the 

 Bamboo ; Saccharum Ravennse, S. Teneriffise, Imperata arundinacea, Lagurus ovatus, 

 Lygeum spartum, and the species of Andropogon, yEgilops, &c. by separate sexes, ex- 

 hibit tropical qualities. The Grasses are also less gi'egarious, and meadows seldomer 

 occur, in the south than in the north of Europe. The generahty are social plants. 



" The distribution of cultivated Grasses is one of the most interesting of all subjects. 

 It is detennined, not merely by climate, but depends on the ci\-ilisation, industi'y, and 

 traffic of the people, and often on historical events. Within the northern polar 

 circle, agricultm-e is found only in a few places. In Siberia grain reaches at the utmost 

 only to 60°, in the eastern parts scarcely above 55°, and in Kamtschatka there is no agri- 

 culture even in the most southern parts (51°). The polar Umit of agriciilture on the 

 North-west coast of America appears to be somewhat liigher ; for, in the more southern 

 Russian possessions (57° to 52°), barley and rye come to matui'ity. On the east coast 

 of America it is scarcely above 50° to 52°. Only in Europe, namely, in Lapland, does 

 the polar limit reach an unusually high latitude (70°). Beyond this, dried fish, and here 

 and there potatoes, supply the place of gi'ain. The grains wliich extend farthest to the 

 north in Eiu'ope are bai'ley and oats. These, which m the milder climates are not used 

 for bread, afford to the inhabitants of the northern parts of Norway and Sweden, of a 

 part of Siberia and Scotland, their chief vegetable noiu-ishment. Rye is the next which 

 becomes associated with these. This is the prevaiHng gi'ain m a great part of the north- 

 ern temperate zone, namely, in the south of Sweden and Norway, Denmark, and in all 

 the lands bordering on the Baltic ; the north of Germany, and part of Siberia. In the 

 latter another very nutritious grain, buck-wheat, is very frequently cultivated. In the 

 zone where rye prevails, wheat is generally to be found ; barley being here chiefly culti- 

 vated for the manufacture of beer, and oats supphing food for the horses. To these there 

 follows a zone in Em-ope and western Asia, where rye disappears, and wheat almost 

 exclusively furnishes bread. The middle, or the south of France, England, part of 

 Scotland, a part of Gemiany, Hungary, the Crimea and Caucasus, as also the lands of 

 middle Asia, where agriculture is followed, belong to this zone. Here the vine is also 

 found ; v.ine supplants the use of beer ; and barley is consequently less raised. Next 

 comes a district where wheat still aboimds, but no longer exclusively furnishes bread, 

 rice and maize becommg frequent. To this zone belong Portugal, Spain, part of France 

 on the jNIediterranean, Italy, and Greece ; further, the countries of the East, Persia, 

 northern India, Arabia, Egypt, Nubia, Barbary, and the Canary Islands ; in these lat- 

 ter comitries, however, the culture of maize or rice towards the south, is always more 

 considerable, and in some of them several kinds of sorghum (doura) and Poa Abyssinica 

 come to be added. In both these regions of wheat, vye only occurs at a considerable 

 elevation ; oats, however, more seldom, and at last enth-ely disappear ; barley affording 

 food for horses and mules. In the eastern parts of the temperate zone of the Old Con- 

 tinent, in China and Japan, our northern kinds of grain are very unfrequent, and rice 

 is foimd to predominate. The cause of this difference between the east and the west 

 of the Old Continent appears to be in the manners and pecuUarities of the people. 

 In North America, wheat and rye grow as in Europe, but more sparingly. Maize 

 is more reared in the Western than in the Old Continent, and rice predommatcs in 

 the southern provmces of the United States. In the torrid zone, maize predomi- 

 nates in America, rice in Asia, and both these grains in nearly equal quantity in 

 Africa. The cause of this distribution is, without doubt, historical ; for Asia is the 

 native coimtry of rice, and America of maize. In some situations, especially in the 

 neighbourhood of the tropics, wheat is also met %rith, but always subordmate to these 

 other kinds of gi-ain. Besides rice and maize, there are, in the torrid zone, several 

 kinds of gi-ain, as well as other plants, which supply the inhabitants with food, either 

 used along with them, or entii^ely occupying their place. Such are, in the New 

 Continent, yams (Dioscorea alata), the maiiihot (Jatropha manihot), and the batatas 



