142 SAXIFKAGACEAE. 



contracted middle. Fruit depressed, of 5 or 6 follicles with the bodies 

 obliquely adnate to the receptacle, each one circumscissile near the base of 

 the free portion. 



1. PENTHORUM [Gronov.] L. Perennial herbs with rootstocks. Flowers 

 greenish-white or yellowish, borne along one side of the cyme-branches. Styles 

 incurved during anthesis, recurved at maturity. Follicles stout, ascending. 



1. P. sedoides L. Plants 1-6 dm. tall, bright-green, the stem, above, and 

 branches angled: leaf -blades narrowly elliptic to elliptic-lanceolate or lanceo- 

 late, 3-15 cm. long, finely serrate: cyme-branches spreading: flowers contiguous: 

 sepals ovate, about 1.5 mm. long, acute: capsules depressed, 4-5 mm. broad, 

 each lobe tipped with the recurved style. Eather common, in meadows and 

 low grounds. Sum. DITCH-STONECROP. 



FAMILY 4. SAXIFRAGACEAE. SAXIFRAGE FAMILY. 



Herbs. Leaves alternate or sometimes opposite: blades simple or 

 compound. Flowers perfect or polygamo-dioecious. Calyx of 5, or rarely 

 of 4 or more, persistent sepals. Corolla of 5, or rarely of 4 or more, 

 petals, or wanting. Androecium of as many stamens as there are sepals, 

 or twice as many. Gynoecium of fewer carpels than there are sepals. 

 Fruit a capsule, or follicles. 



Ovary, and capsules, 2-celled : placentae axial. 1. MICRANTHES. 

 Ovary, and capsules, 1-celled : placentae basal or parietal. 

 Corolla present : terrestrial plants. 



Stamens 5 : petals entire, erose or toothed. 2. HEUCHBEA. 



Stamens 10 : petals 3-cleft or pinnatifld. 3. MITELLA. 



Corolla wanting : aquatic plants. 4. CHRYSOSPLENIUM. 



1. MICRANTHES Haw. Acaulescent herbs with short caudices. Leaf- 

 blades ovate to flabellate, or rarely cordate at the base. Petals nearly equal. 

 Carpels slightly united below. SAXIFRAGE. 



Petals white : cymules open, often raceme-like. 1. M. virginiensis. 



Petals greenish or purple : cymules borne in corymb-like panicles. 2. M . pennsylvanica. 



1. M. virginiensis (Michx.) Small. Leaves spreading, 2-20 cm. long; blades 

 ovate, oval or oblong: cymules becoming open, the axis often elongate: petals 

 oblong to elliptic, 4-4.5 mm. long. Common, in dry rocky places. Spr. 

 EARLY-SAXIFRAGE. 



2. M. pennsylvanica (L.) Haw. Leaves erect or erect-ascending, 5-35 cm. 

 long; blades narowly oblong or elliptic to spatulate: cymules compact, the 

 axis short : petals narrowly lanceolate to oblong-lanceolate, 1.5-3 mm. long. 

 N. S. Eare, in swamps. Sandstones and shales, schists. Sum. SWAMP- 

 SAXIFRAGE. 



2. HEUCHERA L. Perennial herbs with lateral flowering branches. 

 Leaf-blades toothed and usually lobed. Flowers in panicled cymes. Sepals 

 often unequal. Petals entire, erose or toothed. Stamens 5: filaments elon- 

 gate. Styles slender. Capsules gradually narrowed into the slender elongate 

 beaks. Spr. and sum. ALUM-ROOT. BOCK-GERANIUM. 



Flowers essentially regular, the upper sepals sometimes slightly larger than the 



lower. 

 Petals as long as the calyx or shorter : flowering branches leafless. 



1. H. americana. 



Petals longer than the calyx : flowering branches leafy. 2. H. Curtisii. 



Flowers decidedly irregular, the calyx oblique, 2-lipped. 3. H. pubescens. 



