568 A TEXTBOOK OF BOTANY [Ch. XIV 



mesophytic and xerophytic, — the condition called tropo- 

 phytic, — and the following are the principal ones. 



Deciduous Trees; mostly deliquescent, as with meso- 

 phytes, but dropping the foliage, thus eliminating its exces- 

 sive transpiration in winter, when the stems are enwrapped 

 within corky waterproof coverings ; typified by our common 

 forest trees, Maples, Elms, Oaks, etc. Deciduous Shrubs ; 

 of form like the trees, but branching from the ground without 

 trunks, and living as undergrowth or in places where trees 

 are prohibited ; typified by our Dogwoods, Viburnums, etc. 

 In alpine and arctic regions, trees become reduced to shrub- 

 size, and shrubs to trailing forms. Annual Herbs ; erect 

 leafy stems with fibrous roots, completing the cycle of 

 growth from seed to seed in the summer, and lasting over 

 winter as the resting seed only (page 114) ; typified by many 

 weeds, and garden favorites. Herbaceous Perennials; 

 like annuals in the overground parts, but storing food 

 through the winter in underground rootstocks and tubers 

 (page 114) ; typified by Solomon's Sea] (Fig. 134) and many 

 undergrowth herbs of the woods. Biennials are similar in 

 principle. Allied is the form of our Ferns, of which the 

 creeping rootstocks produce annual fronds. In general the 

 creeping condition indicates degeneracy from former upright 

 state, — in this case from tree forms. Turf-forming 

 Grasses ; perennial horizontal interlacing rootstocks sending 

 up annual shoots which die to the ground in winter ; typified 

 by our meadow grasses (page 187), which take possession of 

 all places where trees and shrubs are prohibited. Bulbous 

 Perennials; underground food-storing bulbs, inclosing 

 leaves and flowers which push to the surface and complete 

 flowering, fruiting, and food formation in comparatively 

 short time ; typified by Adder's Tongue, and many bulbous 

 plants of gardens (page 73). This form is well suited to dry 

 climates with considerable moist seasons, as in the Levant, 

 where it abounds. Tuberous Climbers; xerophytic ro- 

 tund stem succulents, sending up temporary leafy shoots in 



