49 2 FLORA. 



i. Opulaster opulifdlius (I..) Kuntze. Eastern NinebarK. (I. F. f. 1882.) 

 A shrub, 1-3 m. high, with recurved branches, glabrous twigs and foliage, the 

 bark peeling off in thin >U ips. Stipules caducous; leaves ovate-orbicular, generally 

 acutely 3-lobed, cordate, truncate or broadly cuneate at the base. 3-5 cm. long, 

 crenate-dentate; pedicels slender, 10-16 mm. long; flowers white or purplish; ca- 

 lyx glabrous or nearly so; follicles 5, glabrous, shining, 8-10 mm. long, acute, 

 obliquely subulate-tipped, twice as long as the calyx. River-banks and in rocky 

 places, Quebec to Ky. and Ga. June. tSj>iraea ofulifolia L.] 



2. Opulaster intermedius Rydb. Prairie Ninebark. Like the preceding, 

 but generally lower, 1-1.5 m. high; leaves orbicular in outline, with rounded lobes, 

 2-6 cm. long, obtuse or subcordate at the base, crenate; pedicels and calyx finely 

 pubescent; ovaries 3 or 4, rarely 2, pubescent, united below, follicles 6-7 mm. long, 

 rounded or obtuse at the apex, tipped with a subulate style. River banks from 111. 

 and Mo. to Colo, and S. Dak. 



2. SPIRAEA L. 



Shrubs. Flowers racemose, cymose, corymbose or paniculate, white or pink, 

 perfect. Calyx persistent, its tube 4-5-lobed. Petals 4-5, inserted on the calyx, 

 short-clawed. Stamens 20-60, distinct, inserted on the calyx; filaments filiform. 

 Disk adnate to the calyx-tube. Pistils commonly 5 (rarely 1-8), superior, alter- 

 nate with the calyx- lobes. Stigmas capitate or discoid; ovules 2-00 . Follicles 

 usually 5, not inflated. Seeds linear, pendulous, the testa dull. [Greek, twisting, 

 the pods twisted in some species.] About 60 species, natives of the north temper- 

 ate zone. Besides the following, about 5 others occur in western N. Am. 

 Flowers in dense terminal panicles. 



Glabrous or nearly so throughout. 1. S. salicifolia. 



Twigs and lower surfaces of the leaves woolly-pubescent. 2. S. tomentosa. 



Flowers in terminal corymbs. 



Leaves broadly oval or ovate, thick, serrate. 3. S. corymbosa. 



Leaves oblong, thin, nearly entire. 4. S. Virginiana. 



1. Spiraea salicifolia L. Willow-leaved or American Meadow-sweet. 

 Quaker Lady. (I. F. f. 1883.) An erect shrub, 6-12 dm. high. Leaves petioled, 

 oblanceolate, obovate, lanceolate or oval, sharply serrate, especially above the 

 middle, 3-5 cm. long, 8-24 mm. wide, or on young shoots much larger, mainly 

 cuneate at the base, pale beneath; flowers white or pinkish-tinged, 4-6 mm. broad; 

 follicles glabrous. In swamps or moist ground, Newf. to the Rocky Mts., Ga. and 

 Mo. Also in northern Europe and Asia. June-Aug. 



2. Spiraea tomentosa L. Hardhack. Steeple-bush. (I. F. f. 1884.) 

 Erect, shrubby, usually simple, the stems floccose -pubescent. Leaves short- 

 petioled, ovate or oval, 3-5 cm. long, 12-25 mm. wide, unequally serrate, gla- 

 brous and dark-green above, woolly-pubescent with whitish hairs beneath; flowers 

 pink or purple, rarely white, about 4 mm. broad; follicles pubescent. In swamps 

 and low grounds, N. S. to Manitoba, Ga. and Kans. July-Sept. 



3. Spiraea corymbosa Raf. Corymbed Spiraea. (I. F. f. 1885.) A shrub, 

 3-10 dm. high, nearly glabrous throughout. Leaves petioled, rounded or slightly 

 cordate at the base, serrate, especially above the middle, green above, paler and 

 sometimes minutely pubescent beneath, 4-7 cm. long, 3-5 cm. wide; flowers white, 

 about 4 mm. broad; follicles glabrous. On banks or in rocky places, mountains 

 of Ga. to N. J . , Ky . M ay -J une. 



4. Spiraea Virginiana Britton. Virginia Spiraea. (I. F. f. 1886.) A gla- 

 brous much-branched shrub, the branches forming wands 3-12 dm. long. Leaves 

 petioled, cuneate or rounded at the base, 4-5 cm. long, 10 -16 mm. wide, green 

 above, pale or slightly glaucous beneath, entire, or with a few low teeth al>ove the 

 middle; flowers white, about 6 mm. wide; pedicels and calyx glaucous; follicles 

 glabrous. On rocks, W. Va., to the mountains of N. Car. and Tenn. June. 



Spiraea Japonica L. f., with oblong-lanceolate acuminate cut-toothed leaves, the 

 branches and corymbose inflorescence finely pubescent, occurs as an escape from cultiva- 

 tion in E. Fenn. 



3. ARUNCUS Adans. 



Tall perennial herbs, with large 2-3-pinnate leaves, stipules minute or wanting, 

 and very numerous white dioecious flowers in panicled spikes. Calyx mostly 



