218 



HUTCHINSON'S POPULAR BOTANY 



FIG. 272. SAFFRON CROCUS (Crocus 

 sativus). 



Corm and section of same, (a) Old corm ; 

 (6) new corm ; (c) bud. 



the Brazilian forests, whose stems bulge 

 out in the middle like enormous barrels ; 

 and the Delabecheas or Bottle-trees of 



/ \ ni~)}''~' C tropical Australia, which have the same 



lumpish mode of growth (fig. 277), to say 

 nothing of the Caulotretus or Monkey- 

 ladders, and the numberless other tropical 

 tree-climbers, whose singular varieties of 

 stem-form flattened and warty, ridged 

 and contorted, net-like and interlacing 

 are the wonder of travellers. We shall 

 return to some of these tropical curiosities 

 presently when considering the means by 

 which slender and weak-stemmed plants 

 maintain an erect position. 



Mention was made a moment ago of " woody trees and shrubs." an 

 expression which recalls the old and somewhat vague classification of 

 Flowering Plants into herbs, shrubs, and trees. Botanists differ very 

 considerably in their definitions of these three forms, and it is hardly 

 necessary to discuss the points of difference ; probably most persons have 

 a tolerably correct idea of the main distinctions upon which the classifica- 

 tion is based. Herbs are plants of com- 

 paratively small size, usually with soft and 

 succulent stems, which die down to their 

 base every year. The crown or root-stock 

 itself may survive, and produce either a 

 fresh plant year after year, when the herb 

 is said to be perennial, or only the follow- 

 ing year, and then it is biennial. If the 

 herb dies completely roots and all in 

 the first year, it is an annual. Perennial 

 plants with branching ^uoody stems, which 

 do not attain to the dignity of trees, or, 

 in other words, do not exceed about 

 twenty feet in height, are shrubs; while 

 perennials of larger growth, if character- 

 ized by a distinct primary stem or trunk, 

 may be fairly classed among trees. No 

 hard-and-fast dividing lines can be drawn 

 between these three forms, however, herbs 

 passing into shrubs, and shrubs into trees, 

 by endless gradations. 



It may be remarked in this connec- 

 tion that the modifying effect of climate 



FIG. 273. GARDEN HYACINTH 

 (Hyacinthus orientalis). 



Section of bulb, showing the overlapping leaves 

 of which it is composed. 



