170 



SAXIFRAGACEAE. 



[VOL. II. 



About 7 species, natives of eastern North America, eastern Asia and the Himalayas. Besides 

 the following another species or variety occurs in the southern Alleghanies. 



i. Astilbe biternata (Vent.) Britton. False Goat's Beard. Astilbe. 



(Fig. 1822.) 



Tiarella biternata Vent. Jard. Malm. 



pi. 54. 1803. 

 Spiraea Aruncusvar. hermaphrodita 



Michx. Fl. Bor. Am. i: 294. 1803. 

 Astilbe decandra D. Don, Prodr. Fl. 



Nepal. 211. 1825. 

 Astilbe biternata Britton, Bull. Torr. 



Club, 20: 475. 1893. 



Erect, 3-6 high, more or less 

 pubescent. Leaves petioled, 2-3- 

 ternately compound, often 2 

 broad; leaflets thin, stalked, ovate, 

 cordate, truncate or rounded at the 

 base, the lateral ones usually ob- 

 lique, acuminate at the apex, 

 sharply serrate or incised, 2 / -5 / 

 long; panicles often i long; 

 flowers sessile or nearly so, about 

 2" broad, yellowish white; petals 

 of the staminate flowers spatulate, 

 those of the perfect ones inurli 

 smaller or none; stamens 10; fol- 

 licles 2, acute, glabrous, about i%" 

 long. 



In woods, mountains of Virginia to 

 North Carolina, Georgia and Tennes- 

 see. Plant with the aspect of Antn- 

 cus. Junr. 



2. SAXIFRAGA L. Sp. PI. 398. 1753. 



Perennial herbs, with alternate opposite or basal entire toothed or pinnatifid leaves, and 

 corymbose paniculate or solitary perfect flowers. Calyx-tube free, or adnate to the base of 

 the ovary, 5-lobed. Petals 5, equal, or in some species unequal, perigynous. Stamens 10, in- 

 serted with the petals; filaments filiform, club-shaped or subulate; anthers didymous. Ovary 

 superior or partly inferior, a-celled, 2-lobed at the summit; styles short; stigmas truncate or 

 capitate; 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 the western parts of North America. 



* Steins prostrate; leaves rounded, opposite ; petals purple. I. S. Oppositifoha. 

 X- # Steins erect or ascending; leaves alternate; petals white or yellow. 

 Flowers yellow; leaves entire. 



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



Stems i-flowered; leaves oblong. 3. 5. Hirculns. 



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



Stems 4'-io' tall; flower commonly solitary, nodding. 4. S. cerniia. 



Stems weak, 2' '-5' long; flowers 1-5, erect. 5. 5. rivnlaris. 



X- -Jf -Jf Stems scapose, naked or bracted, the leaves clustered at the base. 



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



Leaves sharply 3-toothed at the apex. 6. 5 1 . tricuspidata. 



Leaves with white denticulate margins. 7. S. Aizoon. 



t t Leaves deeply 3~5-cleft; petals white. 8. 5. caespiiosa. 

 t t t Leaves soft, obovate or oval with narrowed or spatulate base. 

 Flowers regular; petals all nearly alike. 



Plants large, i-3 tall, growing in wet places. 



Leaves merely denticulate or repand; follicles ovoid. 

 Leaves coarsely and sharply dentate; follicles lanceolate. 

 Plants low, 2'-i8' tall, growing in dry or rocky places. 

 Petals sessile, not clawed. 



Flowers in cymose or at length panicled clusters. 

 Flowers capitate; arctic and alpine sped* 

 Petals narrowed into a claw. 



Flowers few, most or all of them replaced by tufts of leaves. 13. 5". comosa. 

 Inflorescence loose, cymose-paniculate. 



Follicles erect, united to near their summits; styles short. 14. 5. stellaris. 

 Follicles divergent, united only at base; styles filiform. 15. S. Grayana. 

 Flowers irregular, 3 petals large, 2 smaller. 16. S. Micliau.i ii. 



t t t t Leaves soft, orbicular, cordate, dentate all around. 17. 5. Genni. 



Q. S. Pennsylvanica. 

 10. 5. micranthidifolia. 



n. S. Virginiensis. 

 12. S. nivalis. 



