GERMINATION OF TREES AND' SHRUBS 



335 



TILIACE^. 



There is considerable variation in the character of the cotyle- 

 dons and the germination of members of this family, as indicated 

 by Lubbock. Lubbock^^ describes two species of Tilia, the T. 

 petiolaris and T. vulgaris. 



Tilia americana, L. Basswood. The seeds of this species were 

 germinating albundantly in the field by the middle of May ; there 

 was no germination in the greenhouse. Germination epigaeous; 

 root stout, straight or twisted, hypocotyl smooth, often reddish ; 



Fig. 112 Fig-. 113 Fig. 114 



Fig. 112. — Trichomes of Vitis viilpina. Drawn by C. M. King. 



Fig. 113, — Trichomes from leaf of young seedling of Tilia americana. 

 Drawn by C. M. King. 



Fig. 114. — Trichomes from upper surface of leaf of seedling of Co^-nus 

 alternifolia. Drawn by C M. King. 



■cotyledons foliaceous, petioled, stalks pubescent, often reddish, 

 deeply palm'ately 5-lobed, light green in color, slightly pubescent 

 on the margins ; plumule pubescent. Third leaf coarsely den- 

 tate, both surfaces smooth, prominently reticulately veined, slight 

 pubescence on the midvein and margins. Veins on upper sur- 

 f-ice pale in color, on under surface darker. Stem and petioles 



^^A contribution to our knowledge of seedlings, 1, p. 275. 



