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. 108. Grass-of-Parnassus (Parnassia palustris), 
After Britton & Brown, Il], Fl. Northeast. U. S. 
Fig. 107, Alum-root (Heuchera Americana), After 
Britton & Brown, Ill. Fl. Northeast. U. S. 
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. Philadelphus, the mock- 
orange, or, as it is altogether 
falsely called, “syringa,” be- 
longs here, as does also the 
*See article ‘‘Concerning Saxifrages,’’ by T. H. Kearney, Jr., THe PLant 
WORLD, 3: 37. 1900. 
