SAXIFRAGACEAE. 



4. Saxifraga cernua L. 

 Bulbous Saxifrage. 



[VOL. II. 



Nodding or Drooping 

 (Fig. 1826.) 



Sa.i-ifraga cernua L. Sp. PI. 403. 1753. 



Stem weak, slender, ascending, pubescent but scarcely 

 glutinous, 4'-i2 / long. Leaves alternate, the basal and 

 lower ones petioled, broadly renifonn, palmately 5-7- 

 lobed, usually less than i' wide; upper leaves smaller, 

 sessile, 3-lobed or entiie and bract-like, often bearing 

 small bulbletsin their axils; flowers 1-3, terminal, nodding, 

 white, 4 // -5 // broad; petals obovate, sometimes retuse, 

 3-4 times as long as the ovate calyx-lobes. 



Newfoundland, Labrador, and through arctic America to 

 Alaska. Also in arctic and alpine Europe and Asia. .Summer. 



5. Saxifraga rivularis L,. Alpine Brook 

 Saxifrage. (Fig. 1827.) 



Saxifraga rivularis L. Sp. PI. 404. 1753. 



Densely tufted, glabrous or sparingly pubescent, 

 matted, \'-$ f high. Leaves alternate, the basal and 

 lower ones slender-petioled, renifonn, 3-5-lobed, seldom 

 more than 3" wide; petioles dilated at the base; upper 

 leaves lanceolate or ovate, entire or slightly lobed, 

 mainly sessile; flowers 1-5, terminal, erect, white, 

 about 3"-5" broad; calyx-lobes ovate, obtuse, slightly 

 shorter than the ovate-oblong petals; tips of the capsule 

 widely divergent, its base adnate to the calyx. 



Alpine summits of the White Mountains, Labrador, arctic 

 America and south in the Rocky Mountains to Colorado. 

 Also in arctic and alpine Europe and Asia. Summer. 



6. Saxifraga tricuspidata Ret/. Three-toothed 

 Saxifrage. (Fig. 1828.) 



Saxifraga tricuspidata Retz, Prodr. Fl. Scand. Ed. 2, 104. 1795. 



Tufted, flowering stems strict, erect, 2'-8' high, the leaves 

 densely clustered at the base, oblong or oblong-spatulate, 

 parchment-like, 4"-7 // long, sharply 2-3-dentate at the apex, 

 narrowed at the base, sessile, the margins ciliate with short 

 hairs; scape bracted; flowers several, corymbose, yellow, 4"- 

 5" broad; sepals ovate, coriaceous, obtusish, much shorter 

 than the oblong-obovate or narrowly oblong petals; capsule 

 tipped with the diverging styles, its lower part adnate to the 

 calyx. 



In rocky places, Newfoundland and Labrador to Hudson Bay, 

 west through arctic America to Alaska, south to Lake Superior 

 and in the Canadian Rocky Mountains. Also in arctic Europe. 

 Summer. 



