486 The Plums and Cherries 



with the Nectarine and two or three other Asiatic shrubs, constitute the genus, of 

 which the Peach is the type. 



III. THE PLUMS AND CHERRIES 



GENUS PRUNUS [TOURNEFORT] LINN^US 



RUNUS comprises about 65 species of trees or shrubs, well distributed 

 over the northern hemisphere. They are especially numerous in 

 North America. 



The leaves and bark abound in a bitter and astringent principle, 

 and most all of them produce hydrocyanic acid upon maceration of the bark, 

 leaves, or seed, with water. The fruit of most of them is edible, many being cul- 

 tivated from time immemorial and now known in a great number of highly 

 improved forms. 



The leaves are alternate, simple, usually saw-toothed, stalked and deciduous, 

 their stipules quite large, usually glandular and deciduous, the enlarged bud scales 

 conspicuous before falling; the flowers, soHtary, umbellate, or corymbose, appear 

 with or before the leaves mostly on branchlets of the previous season; the calyx- 

 tube is obconic, urn-shaped or tubular, 5-lobed and deciduous; the 5 petals are 

 white to rose-colored, inserted in the mouth of the calyx-tube on a marginal disk, 

 deciduous, rarely wanting; the 15 to 20 stamens are usually borne with the petals in 

 three series; the filaments are thread-Hke, the anthers oval, 2-celled, and open 

 lengthwise; the i -celled ovary is borne in the bottom of the calyx-tube; the termi- 

 nal style is capped by a broad, simple stigma; the 2 ovules are pendulous. The 

 drupe is smooth, sometimes glaucous; stone bony, smooth or nearly so, more or 

 less compressed, indehiscent; seed i, rarely 2; cotyledons fleshy. 



The generic name, Prunus, is the ancient Latin name of the Plum, Primus 

 domestica Linnaeus, the type species. There are probably 25 shrubby species, as 

 well as the following arborescent ones, in our area : 



I. Plums; fruit usually with a ventral groove and a flattened stone (stone 

 in No. I nearly globular, little flattened). 

 Umbels several-flowered; native trees. 



Drupe purple, with a bloom (variously colored in No. 2), less than 

 15 mm. thick. 

 Drupe globose; stone nearly globular; leaves glabrous; southern tree. i. P. umbellatu. 

 Drupe oblong or oval; stone longer than thick; leaves pubescent. 

 Twigs glabrous. 



Stone rounded at base; Arkansas, Louisiana, and Texas tree. 2. P. tarda. 

 Stone pointed at base. 



Leaves hairy all over beneath; southeastern tree. 3. P. mitis. 



Leaves hairy only on the midrib beneath; Pennsylvania 



tree. 4. P alleghaniensis. 



Twigs closely pubescent; leaves hairy, beneath; southern tree. 5. P. injucimda. 

 Drupe red or orange, without bloom; mostly over 20 mm. thick. 

 Calyx-lobes entire. 



