172 SAXIFRAGACEAE. [Vor II. 
4. Saxifraga cérnua L. Nodding or Drooping 
Bulbous Saxifrage. (Fig. 1826.) 
Savxifraga cernua I, Sp. Pl. 403. 1753. 
Stem weak, slender, ascending, pubescent but scarcely 
glutinous, 4/-12’ long. Leaves alternate, the basal and 
lower ones petioled, broadly reniform, palmately 5-7- 
lobed, usually less than 1’ wide; upper leaves smaller, 
sessile, 3-lobed or entiie and bract-like, often bearing 
small bulblets in 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 1. Alpine Brook 
Saxifrage. (Fig. 1827.) 
Saxtfraga rivularts I,. Sp. Pl. 404. 1753. 
Densely tufted, glabrous or sparingly pubescent, 
matted, 1/-3/ high. Leaves alternate, the basal and 
lower ones slender-petioled, reniform, 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 Retz. Three-toothed 
Saxifrage. (Fig. 1828.) 
Saxifraga tricuspidata Retz, Prodr. Fl. Scand. Ed. 2, 104. 1795. 
Tufted, flowering stems strict, erect, 2’-S’ 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 
Sees Canadian Rocky Mountains. Also in arctic Europe. 
