322 THE KINDS OF PLANTS 



P. angustifdlia, Marsh. Chickasaw plum. Mountain clierry. Fig. 479. 

 Smaller, the young growths smooth and zigzag and usually reddish: leaves 

 lanceolate to oblong-lanceolate, often trough-shaped, shining, finely serrate, 

 cherry-like: fruit a small thin-fleshed shining plum on 

 a long pedicel. Delaware, south ; also in cultivation. 



aaa. Cherries: flowers in nmbel-like clusters: fruit 

 small and nearly globular, early -ripening , usu- 

 ally without a prominent suture and "bloom," the 

 stalk slender. 



P. Cerasus, Linn. Sour cherry. Round-headed 

 tree, with flowers in small clusters from lateral buds: 

 480 Primus Avium l eaves hard and stiffish, short-ovate or obovate, gray- 

 ish green, serrate: fruit small, sour. Europe. 

 P. Avium, Linn. Sweet cherry. Fig. 480. Straight grower, the "leader" 

 prominent in young trees, with flowers in dense clusters from lateral spurs: 

 leaves oblong-ovate, dull and soft, on the young growths hanging : fruit 

 usually rather large, sweet. Europe. 



4. RUBUS. Bramble. 



Shrubs, usually thorny, the canes or shoots dying after fruiting, with 

 alternate digitately compound leaves : flowers white, in clusters, with 

 5-parted calyx and 5 petals: ovaries many, ripening into coherent drupelets. 



a. Raspberries: drupelets or berry separating from the torus. 



R. occidentalis, Linn. Black raspberry. Figs. 128, 263. Canes long 

 and thorny, glaucous, rooting at the tips late in the season: leaves of mostly 

 3 ovate doubly-toothed leaflets: flowers in close, umbel-like clusters: fruits, 

 firm, black (sometimes amber-color). Woods, and common in cultivation. 



R. Strigosus, Michx. Bed raspberry. Canes erect and weak-prickly, 

 more or less glaucous, not rooting at tips, leaflets oblong-ovate: flowers in 

 racemes: fruits soft, red. Woods, and cultivated. 



aa. Blackberries: drupelets adhering to the torus (the torus forming the 



"core" of the berry). 



R. nigrobaccus, Bailey (B. villosus of some). Common blackberry. 

 Tall, very thorny: leaflets 3 or 5, ovate and pointed, toothed, hairy beneath: 

 flowers large, in open racemes: fruit thimble-shaped and firm, black when 

 ripe. Woods, and cultivated. 



R. villdsus, Ait. (B. Canadensis of some). Northern dewberry. Trail- 

 ing and rooting at tips, prickly: leaflets 3-7, ovate-acuminate or oblong-ovate, 

 toothed: flowers 1-3, on erect, short peduncles, large: fruit like a small and 

 shining blackberry. Sterile fields, and in cultivation. 



R. trivialis, Michx. Southern dewberry. Fig. 158. Long-trailing, 

 very thorny and bristly: leaves 3-5, more or less evergreen, mostly lance- 

 oblong and small, strong-toothed: flowers 1-3: fruit black. Sands, Vir- 

 ginia, south; also in cultivation. 



