SAX2FRAGACEAE. 477 



usually persistent. Petals usually 4 or 5, rarely none. Stamens equal 

 in number to or twice as many as'the petals, in apetalous species as many 

 or twice as many as the calyx-lobes, perigynous or epigynous ; filaments 

 distinct. Disk generally present. Carpels usually 2, distinct or united, 

 but upper portion free, mostly fewer than the stamens. Seeds commonly 

 numerous ; endosperm generally copious, fleshy ; embryo small, terete. 

 About 70 genera and 600 species, of wide geographic distribution. 



Large herbs; leaves 3-ternate; flowers polygamous. i. Astilbe. 



Leaves simple, cleft, lobed or 3-foliolate; flowers perfect. 

 Placentae axial. 



Ovary superior or nearly so; stamens 10. 2. Saxifraga. 



Ovary more or less adnate to the calyx-tube. 

 Stamens 5, in our species. 



Petals deciduous. 3. Therofon. 



Petals persistent. 4. Sullivantia. 



Stamens 10. 2. Saxifraga. 



Placentae almost basal. 5- Tiarella 



Placentae parietal. 



Petals present (in our species) ; terrestrial plants. 



Petals entire. 6. Heuchera. 



Petals lobed or pinnatifid. 7. Mitella. 



Petals none; small aquatic plants. 8. Chrysosplenium. 



i. ASTILBE Hamilt. 



Erect perennial herbs, with small spicate flowers in terminal panicles. Calyx 

 campanulate, 4-5 -lobed. Petals 4 or 5 (in our species), linear-spatulate, inserted at 

 the base of the calyx. Stamens 8-10; filaments elongated. Ovary superior or 

 nearly so, 2-3-celled, deeply 2-3-lobed at the apex; styles 2-3'; ovules oo. Capsule 

 2-3-lobed, separating into 2 or 3 follicle-like carpels, each usually few-seeded. 

 Seeds small, the testa loose, tapering at each end. [Greek without brightness.] 

 About 7 species, natives of eastern N. Am., eastern Asia and the Himalayas. 



i. Astilbe biternata (Vent) Britton. FALSE GOAT'S BEARD. ASTILBE. 

 (I. F. f. 1822.) Erect, 1-2 m. high, more or less pubescent. Leaves petioled, 

 often 6 dm. broad; leaflets thin, stalked, ovate, the lateral ones usually oblique, 

 acuminate, sharply serrate or incised, 5-12 cm. long; panicles often 3 dm. long; 

 flowers sessile or nearly so, about 4 mm. broad, yellowish white; petals of the 

 staminate flowers spatulate, those of the perfect ones much smaller or none ; 

 stamens 10; follicles 2, acute, glabrous, about 3 mm. long. In woods, mountains 

 of Va. to Ga. and Tenn. Plant with the aspect of Aruncus. June. 



2. SAXIFRAGA L. 



Perennial herbs, with entire toothed or pinnatifid leaves, and perfect flowers. 

 Calyx-tube free, or adnate to the base of the ovary, 5 -lobed. Petals 5, perigynous. 

 Stamens IO, inserted with the petals ; anthers didymous. Ovary superior or partly 

 inferior, usually 2-celled, 2-lobed at the summit; styles short; ovules oo, on axial 

 placentae. Capsule 2-beaked, many-seeded. Seeds small, the testa smooth or 

 .roughened. [Greek, stone-breaking, from reputed medicinal qualities.] About 

 210 species, nearly all natives of the north temperate zone. Besides the following, 

 about 50 others occur in western N. Am. 



* Stems prostrate ; leaves rounded, opposite; petals purple. 



i. S. oppositifolia. 



* * Stems erect or ascending; leaves alternate; petals white or yellow. 

 Flowers yellow; leaves entire. 



Stems several-flowered; leaves linear. 2. S. autumnalis. 



Stems i-flowered: leaves oblong. 3. S. Hirculus. 



Flowers white: leaves 3~7-lobed, mostly wider than long. 



Stems 10-25 cm. tall; flower commonly solitary, nodding. 4. S. cernua. 

 Stems weak, 5-12 cm. long; flowers 1-5, erect. 5. S. rtvularis. 



* * * Stems scapose, naked or bracted, the leaves clustered at the base. 



f Leaves stiff, oblong or oblanceolate ; petals yellow or yellowish. 



