THE CLIMAX FOREST AND ITS PREDECESSOR 209 



each twig, giving the twig a square cross-section. Leatherwood 

 is low, not over 7 feet high, with very soft, white wood and very 

 tough, fibrous bark. The branchlets are jointed, and the leaves 

 are very short-petioled. Elderberry (Fig. 262) is readily recog- 

 nized by the very large amount of pith in the stems. The wood 

 layer is relatively thin. Strawberry bush (Fig. 263) is a low 

 shrub with more or less of a creeping habit. The leaves are 

 almost without stalks, lance-shaped, and finely toothed. 



On the ground of such a forest there are a large number of 

 plants (Fig. 55) that spring up quickly in the spring before the 

 trees are in leaf, blos- 

 som, and mature their 

 fruit before they are 

 so densely shaded as 

 to preclude their in- 

 tense activity. The 

 spring beauty, spring 

 cress, toothwort, hepa- 

 tica (Fig. 139), blood- 

 root, red and white 

 trillium, dog-tooth 

 violet, jack-in-the- 

 pulpit (Fig. 264), green 

 dragon (Fig. 266), Dutchman's breeches, wild ginger, all belong 

 to this group. This vernal flora consists of plants in whose 

 underground stems or succulent roots there is stored abundant 

 food for this burst of speed in the accompKshment of their life- 

 cycle. In many cases, too, their leaves and flower buds are 

 warmly clothed in hair, and not a few have leaves that cuddle 

 close to the warm earth in dense clusters. 



Later the ground is pre-empted by plants that are better 

 able to endure the shade and that take more time to blossom 

 and mature their fruit. Such are the long-spur (Fig. 143) and 

 Canadian violets (Fig. 142), wood violet, the latter with a pal- 

 mately five- to nine-lobed hairy leaf, wood phlox, the columbine 



Fig. 265. — Pigeon berry or dwarf cornel, Cornus 

 canadensis. 



