ROSACEiT-:. (UOSK FAMILY.) 151 



II. Ovaries inferior or enclosed in the calyx-tube. 

 Tribe V. POTERIE.-E. Pistils 1-4, hccominR arhcnes, mnipleU'ly enclosed in the 

 dry anil linn caiyx-tulte, which is constricted or nearly closed at the thmat. Herbs 

 with conipound ur lobed leaves. Petals often none. 

 12. Alcheiuilla* Calyx urceobit«, bracteolate. Petals none. SUunens 1-4. Flowers 



minute, clustered. 

 lo. Agriinonia. Calyx turbinate, with a margin of hooked prickles. Stiiiuens 5-12. 

 FInwei-s yellow, in long racemes. 



14. Poteriiim. Calyx-lobes petaloid ; tube 4-angled, naked PeUdsnonc. Flowci-s densely 



capitate or .spicate. 

 Tribe VI. KOSE.^. Pistils many, becoming bony acheucs, enclosed in the glob*)se or 

 urn-shaped fleshy calyx-tube, which resembles a pome. Petids conspicuous. Stamens 

 numerous. 



15. Rosa. The only genus. Prickly shrubs with pinnate leaves. 



Tribe VII. POME..E. Carpels 2-5, enclosed in and coalescent with the fleshy or berrj'- 

 like calyx, in fruit becondng a 2 - several-celled pome. Trees or shrubs, with stipulea 

 free from the petiole. 



a. Cells of the compound ovary as many as the styles (2-5), each 2- (rarely several-) ovuled. 



16. Pyrus. Pome containing 2-5 papery or cartilaginous carpels. 



17. Craticgus. Pome drupe-like, with 1-5 bony stones or kernels. Usually thoniy. 

 b. Cells of the compound ovary becoming twice as many as the styles, each 1-ovuled. 



IS. Amelanchier. Pome usually of 5 ca^jels : each becomes incompletely 2-celled by a 

 projection from its back ; otherwise as Pyrus. 



1. PRtJNUS, Tourn. Plum, Cherry, etc. 



Calyx 5-cleft ; the tube bell-shaped, urn-shaped or tubular-obcouical, decidu- 

 ous after flowering. Petals 5, spreading. Stamens 15-20. Pistil solitary, 

 with 2 pendulous ovnles. Drupe fleshy, with a l)ony stone. — Small trees or 

 shrubs, with mostly edible fruit. (The ancient Latin name.) 



§ 1. PllUNUS proper (and Cerasps). Drupe smooth, and the stone smooth or 

 somewhat rugged ; Jlowers (usualli/ white) from separate lateral scali/ buds 

 in early spring, preceding or coetaneous with the leaves; the pedicels Jew or 

 several in simple umbel-like clusters. 



1. P. Americana, Marshall. (Wild Yellow or Eed Pm'm.) Tree 

 thorny, 8-20° high; leaves ovate or somewhat ol)Ovate, consjticnoiisli/ pointed, 

 coarsclji or doublij serrate, very veiny, glabrous when mature ; fruit nearly desti- 

 tute of bloom, roundish-oval, yellow, orange, or red, |-§'in diameter, with 

 the turgid stone more or less acute on both margins, or in cultivated states T 

 or more in diameter, the flattened stone with l)roader margins ; ple:isant-tasted, 

 but with a tough and acerb skin. — Woodlands and river-banks, common. 



2. P. maritima, AVang. (Beach Plum.) Low and straggling (1 - 5°) ; 

 leaves ovate or oval, Jinrly serrate, softly pubescent underneath; ])edicols short, 

 pubescent ; fruit globular, pur])le or crimson with a bloom (^-1' in diameter) ; 

 the stone very turgid, orj/^e on one edge, rounded and minutely grooved on the 

 other. — Sea-beaches and the vicinity, N. IJrunswick to Va. It varies, when at 

 some distance from the coast (X. J. and southward), with the leaves smoother 

 and thinner and the fruit smaller. 



3. P. Alleghanidnsis, Porter. A low straggling shrub or small tree 

 (3-15*^ high), seklum tliurnv; leaves lauctulate to vblnnff-orate, ofh n loii'/-aru- 



