92 



ROSACEA. 



Order XXXIX. ROSACE^.— Roseworts. 



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

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

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

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

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

 with simple or compound leaves. 



1. SPIR^A. Z/iww.— Spiraea. 



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

 branches.) 



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

 pels 3 — 8, distmct, rarely united at base, short apiculate, sessile, 

 rarely stiped. Seeds 2 — 15. 



* Skrubbij. 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. li.—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. chamce- 

 drifolia Pursh. 



Mountains of Penn. S. to Geor. W. to Ken. May, June. \i.—Stem 18 

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

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



Corymbose Spircea. 



3. )S. salicifolia 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. alba Ehrh. S. hypericifolia Muhl. according to Torr. 

 <^ Gr. 



Meadows, Arct. Amer. to Geor. June, July." T2- — Stem 3 — 5 feet high, the 

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

 times obtuse. Flowers white or reddish-white. Meadov) 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 grormds. Can. to Geor, July, Aug, T^. — Stem 2 — 3 feet high, cov- 



