92 ROSACES. 



ORDER XXXIX. ROSACEJS. ROSEWORTS. 



Calyx 4 or 5-lobed, with a disk either lining the tube or sur- 

 rounding the orifice. Petals 5, equal, or none. Stamens usu- 

 ally indefinite. Ovaries superior, solitary or several, 1 -celled ; 

 styles lateral. Fruit 1 -seeded nuts, achenia, or follicles contain- 

 ing several seeds ; albumen none. Herbaceous plants or shrubs, 

 with simple or compound leaves. 



1. SPIRAEA. Linn. Spiraea. 



(Supposed to be from the Greek cirsipa, a cord; in allusion to its flexible 

 branches.) 



Calyx 5-cleft, persistent. Petals 5. Stamens 20 50. Car- 

 pels 3 8, distinct, rarely united at base, short apiculate, sessile, 

 rarely stiped. Seeds 2 15. 



* Shrubby. Leaves lobed and toothed. 



1. S. opulifolia Linn. : leaves ovate, often subcordate, 3-lobed, doubly 

 toothed and crenate, petioled, smoothish; corymbs umbel-like, hemispherical, 

 peduncled ; pedicels filiform ; carpels 3 5, at length spreading, much 

 longer than the calyx. 



Banks of streams. Can. to Geor. W. to Oregon. May, June. rj. Stem 

 3 6 feet high, much branched. Flowers numerous, white, in corymbs which 

 are about two inches in diameter. Calyx and pedicels pubescent. Nine-bark. 



** Shrubby. Leaves entire or toothed. , 



2. S. corymbosa Raf. : leaves oval or ovate, on short petioles, whitish be- 

 neath, incisely serrate toward the apex ; corymb terminal, pedunculate, 

 compound, fastigiate, somewhat leafy ; carpels 3 5, smooth. S. chamtc- 

 drifolia Pursh. 



Mountains of Penn. S. to Geor. W. to Ken. May, June. T^. Stem 18 

 inches high, slightly pubescent. Leaves nearly smooth above, pale beneath. 

 Flowers pale rose-color, in a compound pedunculate corymb. 



Corymbose Spiraea. 



3. S. salicjfolia Linn. : stem and peduncles glabrous ; leaves lanceolate 

 or obovate, simply or doubly serrate, smooth ; racemes in dense terminal 

 compound panicles ; carpels 5. distinct, not inflated, scarcely twice as long 

 as the calyx. /S 1 . alba Ehrh. S. hypericifolia Muhl. according to Torr. 

 <f- Or. 



Meadows. Arct. Amer. to Geor. June, July, Tj. Stem 3 5 feet high, the 

 branches purple and brittle. Leaves varying in form, usually acute, but some- 

 times obtuse. Flowers white or reddish-white. " Meadow Sweet. 



4. S. tomentosa Linn. : stem and peduncles reddish tomentose ; leaves 

 ovate-lanceolate, unequally serrate, densely tomentose beneath ; racemes 

 terminal, compound, crowded ; carpels 5, woolly. 



In low grounds. Can. to Geor. July, Aug. Tj. Stem 2 3 feet high, cov- 



