Flowers diœciously polygamous. Calyx 4--5-parted, small. Petals 4--5, spatulate, small, withering-persistent. Stamens 8 or 10. Ovary 2-celled, almost free, many-ovuled; styles 2, short. Capsule 2-celled, separating into 2 follicles, each ripening few seeds. Seed-coat loose and thin, tapering at each end.--Perennial herbs, with twice or thrice ternately-compound ample leaves, cut-lobed and toothed leaflets, and small white or yellowish flowers in spikes or racemes, which are disposed in a compound panicle. (Name composed of ἀ- privative and στίλβη, _a bright surface_, because the foliage is not shining.) 1. A. decándra, Don. Somewhat pubescent (3--5° high); leaflets mostly heart-shaped; petals minute or wanting in the fertile flowers, stamens 10.--Rich woods; mountains of S. W. Va. to N. C. and Ga. Closely imitating Spiræa Aruncus, but coarser. 2. SAXÍFRAGA, L. SAXIFRAGE. Calyx either free from or cohering with the base of the ovary, 5-cleft or parted. Petals 5, entire, imbricated in the bud, commonly deciduous. Stamens 10. Styles 2. Capsule 2-beaked, 2-celled, opening down or between the beaks, or sometimes 2 almost separate follicles. Seeds numerous, with a close coat.--Chiefly perennial herbs, with the root-leaves clustered, those of the stem mostly alternate. (Name from _saxum_, a rock, and _frango_, to break; many species rooting in the clefts of rocks.) [*] _Stems prostrate, in tufts, leafy; leaves opposite; calyx free from the capsule._ 1. S. oppositifòlia, L. (MOUNTAIN SAXIFRAGE.) Leaves fleshy, ovate, keeled, ciliate, imbricated on the sterile branches (1--2´´ long); flowers solitary, large; petals purple, obovate, much longer than the 5-cleft-calyx.--Rocks, Willoughby Mountain, Vt., and northward. (Eu.) [*][*] _Stems ascending; leaves alternate; calyx coherent below with the capsule._ 2. S. rivulàris, L. (ALPINE BROOK-S.) Small, stems weak, 3--5-flowered; lower _leaves rounded, 3--5-lobed_, on slender petioles, the upper lanceolate; _petals white, ovate_.--Alpine region of the White Mts., to Lab. (Eu.) 3. S. aizoìdes, L. (YELLOW MOUNTAIN-S.) Low (3--5´ high), in tufts, with few or several corymbose flowers; _leaves linear-lanceolate, entire, fleshy_, distantly spinulose-ciliate; _petals yellow, spotted with orange, oblong_.--N. Vt. to S. W. New York, N. Mich., and northward. June. (Eu.) 4. S. tricuspidàta, Retz. Stems tufted (4--8´ high), naked above; flowers corymbose, _leaves oblong or spatulate, with 3 rigid sharp teeth_ at the summit; _petals obovate-oblong, yellow_.--Shore of L. Superior, and northward. (Eu.) [*][*][*] _Leaves clustered at the root; scape many-flowered, erect, clammy-pubescent._ [+] _Petals all alike._ 5. S. Aizòon, Jacq. Scape 5--10´ high; _leaves persistent, thick, spatulate, with white cartilaginous toothed margins_; calyx partly adherent; petals obovate, cream-color, often spotted at the base.--Moist rocks, Lab. to N. Vt., L. Superior, and northward. (Eu.)