§ 1. SPIRÆA proper. _Erect shrubs, with simple leaves; stipules obsolete; pods mostly 5, several-seeded._ 1. S. betulæfòlia, Pall., var. corymbòsa, Watson. Nearly smooth (1--2° high); leaves oval or ovate, cut-toothed toward the apex; _corymbs large, flat_, several times compound; _flowers white_. (S. corymbosa, _Raf._)--Mountains of Penn. and N. J. to Ga., west to Ky. and Mo. 2. S. salicifòlia, L. (COMMON MEADOW-SWEET.) _Nearly smooth_ (2--3° high); leaves wedge-lanceolate, simply or doubly serrate; _flowers in a crowded panicle_, white or flesh-color; pods smooth.--Wet or low grounds, Newf. to the mountains of Ga., west to Minn. and Mo.; also to the far northwest. (Eu.) 3. S. tomentòsa, L. (HARDHACK. STEEPLE-BUSH.) _Stems and lower surface of the_ ovate or oblong serrate _leaves very woolly_; flowers in short racemes crowded in a dense panicle, rose-color, rarely white; pods woolly.--Low grounds, N. Scotia to the mountains of Ga., west to Minn. and Kan. § 2. ULMÀRIA. _Perennial herbs, with pinnate leaves and panicled cymose flowers; stipules kidney-form; pods 5--8, 1--2-seeded._ 4. S. lobàta, Jacq. (QUEEN OF THE PRAIRIE.) Glabrous (2--8° high); leaves interruptedly pinnate; the terminal leaflet very large, 7--9-parted, the lobes incised and toothed; panicle compound-clustered, on a long naked peduncle; flowers deep peach-blossom color, handsome, the petals and sepals often in fours.--Meadows and prairies, Penn. to Ga., west to Mich., Ky., and Iowa. § 3. ARÚNCUS. _Perennial herbs, with diœcious whitish flowers in many slender spikes, disposed in a long compound panicle; leaves thrice pinnate; stipules obsolete; pods 3--5, several-seeded; pedicels reflexed in fruit._ 5. S. Arúncus, L. (GOAT'S-BEARD.) Smooth, tall; leaflets thin, lanceolate-oblong, or the terminal ones ovate-lanceolate, taper-pointed, sharply cut and serrate.--Rich woods, N. Y. and Penn. to Ga. in the mountains, west to Iowa and Mo. 3. PHYSOCÁRPUS, Maxim. NINE-BARK. Carpels 1--5, inflated, 2-valved; ovules 2--4. Seeds roundish, with a smooth and shining crustaceous testa and copious albumen. Stamens 30--40. Otherwise as Spiræa.--Shrubs, with simple palmately-lobed leaves and umbel-like corymbs of white flowers. (Name from φῦσα, _a bladder_, and καρπός, _fruit_.) 1. P. opulifòlius, Maxim. Shrub 4--10° high, with long recurved branches, the old bark loose and separating in numerous thin layers; leaves roundish, somewhat 3-lobed and heart-shaped; the purplish membranaceous pods very conspicuous. (Spiræa opulifolia, _L._ Neillia opulifolia, _Benth. & Hook._)--Rocky banks of streams, N. Eng. to Fla., west to Mo., and the Pacific northward. Often cultivated. 4. GILLÈNIA, Moench. INDIAN PHYSIC.