592 ZONES AND REGIONS [Pr. Ill, Sect. II 



ths forest, and therefore the xerophilous character of the meadow during 

 winter is far less marked than is that of the forest. Superficial thaws, 

 involving, as they do, a rise in the temperature and rate of transpiration 

 of the twigs, are prejudicial to the forest, but, on the contrary, are beneficial 

 to the shallow-rooted meadow. In mild winters the meadow remains 

 uninterruptedly green, and the occurrence of isolated flowers shows that 

 the processes of growth and nutrition are not arrested. 



Meadow-plants during the vegetative season are devoid of any marked 

 protective devices against transpiration ; their structure is hygrophilous, 

 even if less markedly so than that of the herbaceous shade-flora of the 

 forest. The blades are large, their thickness relatively slight, the cuticle 

 moderately developed, protective coatings are absent or weakly developed ; 

 succulent plants and under-shrubs are rare, except on dry soil. The chief 

 constituents of the meadow are perennial grasses, usually tufted, less 

 frequently provided with creeping rhizomes, and their riband-like, flat, 

 herbaceous, bright green leaves do not roll up in dry weather. Between 

 them grow perennial and biennial — rarely annual — herbs, the majority 

 of which possess rosette-like main shoots, from which there arise, during 

 the vegetative season, fertile lateral shoots that dry up before winter. 

 Perennial herbs that retain only their subterranean parts are relatively rare, 

 for instance Colchicum and species of orchids. 



Grasses and perennial herbs usually form a dense continuous sward. 

 Only on more sterile soil are broad intervening spaces occupied by mosses. 

 The occurrence of completely bare places denotes increased dryness of soil, 

 and the vegetation then assumes a xerophilous character approximating 

 to that of the steppe. Such dry meadow, where deep-rooted perennials 

 usually dominate the grasses, may be termed grass-waste. Its occurrence 

 is always due to local edaphic influence. 



The steppe of the cold-winter belts is distinguished from that of warmer 

 districts by a lower growth. Small woody plants, which bring about a 

 transition to the savannah, are commoner in them than in meadow — which 

 is entirely herbaceous, except in the case of the mountain-meadow to be 

 subsequently described. Under-shrubs are quite common in the steppe. 

 Steppe-grasses usually have narrower leaves than meadow-grasses, and 

 many species possess the property of rolling up in dry weather. This 

 is an effective, but not the sole, protective measure against loss of water; 

 there are also coatings of wax, thick cuticle, and a denser structure. 

 Annuals, or rather ephemerals. are more numerous in the steppe than 

 in the meadow ; as are also tuberous and bulbous plants. Evergreen 

 perennial herbs and under-shrubs usually have small leaves, and are 

 generally provided with protective coatings, especially in the form of 

 air-containing hairs. Succulent plants are much commoner than in meadow, 

 especially in North America. The grassy sward of the steppe is frequently 



