166 



ROSACEA. Frunus. 



21. Acaena. Calyx-lobes valvate, deciduous ; the tube oblong, becoming armed with barbed 



prickles. Petals none. Perennial herbs, with pinnate leaves, and densely spicate-clus- 

 tered flowers. t> . i 



22. Poterium. Calyx-lobes imbricate, deciduous, petaloid ; the tube 4-angled, naked. 1 etals 



none. Herbs with pinnate leaves, and densely capitate or spicate flowers. 



Tribe V. EOSEjE. Carpels many, in fruit bony akenes, enclosed and concealed in tlie 

 globose or urn-shaped fleshy calyx-tube, which resembles a pome. Petals conspicuous, 

 ytamens numerous. 



23. Rosa. The only genus. Erect shrubs, with pinnate leaves. 



Suborder III. POMExE. 



Carpels 2 to 5, enclosed in and mostly adnate to the fleshy calyx-tuhe, in fruit 

 becoming a 2 - several-celled pome. Ovules erect or ascending, a pair in each carpel 

 (more numerous in cultivated apples), ascending. Styles often united below. — 

 Trees or shrubs, with stipules free from the petiole or nearly so. 

 * Evergi-een : carpels partly free and separating. 



24. Heteromeles. Carpels only 2, tomentose above, lightly united and in flower nearly supe- 



rior, becomuig thin and papery, and closely included in the berry-like calyx. 



* * Deciduous-leaved : carpels 2 to 5, united and coalescent with the fleshy or berry-like calyx. 



25. Crateegus. Ovary 2 - 5-celled ; the fruit drapaceous, of 2 to 5 bony 1 -seeded stones, either 



separal lie or united into one. Branches usually thorny. 



26. Pyrus. Ovary 2 - 5-celled ; the fruit a proper pome, with papery or cartilaginous and undi- 



vided 2-se'eded cells or carjiels. 1 1- -1 1 



27. Amelanchier. Ovary 5-celled ; the cells 2-ovuled and 2-seeded, but in fruit each divided 



into two by a partition from the back. Otherwise Kke Fyriis. 



Anomalous Genus, 



28. Canotia. Calyx free from the septicidally 5-valved exserted capsule. Cells 1 -seeded. Sta- 



mens 5, hypogynous. A leafless shmb, with solitary flowers. 



1. PRUNUS, Tourn. PLrji, Ciierky, &c. 



Calyx campanulate or turbinate, 5-cleft, deciduous. Petals 5, spreading. Stamens 

 1.5 to 25, inserted with the petals. Ovary solitary, free, with 2 pendulous ovules : 

 style terminal. Fruit a more or less fleshy drupe, with usually a bony stone con- 

 taining one or rarely two seeds. — Trees or shrubs ; leaves alternate, simple, usually 

 serrulate; flowers white or rose-colored, solitary or fascicled in the axils, or in 

 terminal racemes. 



Species about 80, widely dispersed through the northern hemisphere, but mostly confined to 

 temperate regions. Of the 20 North American species, 14 are found only in the Atlantic btates, 

 froin ('aiKHbi t.. Mexico. This comprehensive genus now includes several of our most dehcious 

 and us, lul IViiits, formerly referred to several genera, such as the Almond, with a somewhat 

 tilirous liittrd stnne,P. (Amygdahis) communis, — the Peach and Nectarine, with wrinkled stone, 

 P ( ImimilaJus) 7Vr«V-re,— the Apricot, P. Armcniaca {Armcniaca vulgaris), —the Garden iluin, 

 P dumckica —the Sloe, P. spinosn,—the Garden Cherries, P. Cerasus (Cerasus vulgaris), — also 

 the Cherry- Laurel, /'. Lnuro-Crrasus (Lauroccrasus offidnaJis), &c. Many of the species have 

 medicinal virtues, and the principle or elements of prussic (cyanohydric) acid so abound in some 

 species, especially in their kernels and bark, as to make them actually poisonous when eaten 

 freely The foliage and voung branches of some of the Cherries become poisonous to cattle wlien 

 wilted. The six Californian species represent nearly as many sections, which have been more or 

 less recently regarded as genera, but the limiting characters prove to be too indeimite. Ibe 

 American specie^s of Plum^belonging to the first section) diff-er from those of the Old W orld m 

 haviiio- the leaves folded (conduplicate) instead of convolute in the bud, the fruit with little or 

 no bloom, and some of them have very turgid instead of flattened stones, thus connecting this 

 section with the following one. 



