650 



FAMILIES OF ANGIOSPERMS. 



dogtooth violet (Erythronium americanum), shown in fig. 538, 

 is quite different from any species of trillium. It differs more 



from any of the 

 species of trillium 

 than they do from 

 each other. The 

 perianth is .of six 

 parts, light yellow, 

 often spotted near 

 the base. Stamens 

 are_6. The ovary 

 is obovate, taper- 

 ing at the base, 3- 

 valved, seeds rather 

 numerous, and the 

 style is elongated. 

 The flower stem, or 

 scape, arises from 

 a scaly bulb deep 

 in the soil, and is 

 sheathed by two el- 

 liptical - lanceolate, 

 mottled leaves. 

 The smaller plants 



Adder-tongue Urythronmm). At lelt below pistil and t flnwpr smH 



three stamens opposite three parts of the penanth. Bulb nave IJ 



but one leaf, while 



the bulb is nearer the surface. Each year new bulbs are formed at 

 the end of runners from a parent bulb. These runners penetrate 

 each year deeper in the soil. The deeper bulbs bear the flower 

 stems. 



1137. Genus lilium. While the lily differs from either the 

 trillium or erythronium, yet we recognize a relationship when 

 we compare the perianth of six colored parts, the 6 stamens, 

 and the 3 -sided and long 3-loculed ovary. 



1138. Family Liliaceae. The relationship between genera, as 

 between trillium, erythronium, and lilium, brings us to a still 



Fig. 538. 

 Adder-tongue (erythronium). At left below pistil ,_and 



