122 



FAMILIES OF FLOWERING PLANTS 



ously clustered flowers. Sepals and petals usually 5, the stamens equal 



or twice as many in number; 



carpels one or more, generally 



2, distinct or partly united; 



fruit a capsule, follicle, or 



berry. 



Saxifraga is by far the 

 largest genus, comprising over 

 200 species, all of which are 

 perennial herbs. While the 

 group is quite a natural one, 

 its subgenera are strongly 

 marked. Thus some species 

 have solitary yellow flowers; 

 others dense panicles of creamy 

 white blossoms; in still others 

 the flowers are pink.* Numer- 

 ous other genera are repre- 

 sented in the United States, 

 one of the most interesting 



Fig. 107. Alum-root (Heuchera Americana). 

 Britton & Brown, 111. Fl. Northeast. U. vS. 



After 



Fig. 108. Grass-of-rarnassus (Parnassia paliisli is). 

 After Britton & Brown, 111. Fl. Northeast. U. S. 



*See article •'Concerning Saxifrages," by 

 World, 3: 37- 1900. 



being Heuchera, which is 

 characterized by large simple 

 basal leaves and scapes ter- 

 minated by panicles of deli- 

 cate flowers, white or vari- 

 ously-colored (see Fig. 107). 

 The various hydrangeas, sev- 

 eral of which may be ranked 

 among our most desirable 

 hardy shrubs for lawn plant- 

 ing, belong to this family. 

 The conspicuous florets in a 

 cluster of hydrangea blos- 

 soms are "neutral," that is, 

 they are without stamens or 

 pistils. Sometimes the whole 

 cluster is sterile in this man- 

 ner. PhUadelphus, the mock- 

 orange, or, as it is altogether 

 falsely called, "syringa," be- 

 longs here, as does also the 



T. H. Kearney, Jr., The Plant 



