ROSACEA. (rose family.) 147 



Ttflbe II. POTERIEJE. Pistils 1-4, one-ovuied, becoming achenia, and enclosed in 



the urn-shaped tube of the dry persistent calyx, which is constricted or nearly closed at the 

 throat Petals often wanting 



4. Poterium. Petals none. Lobes of the calyx 4, petal-like. Style terminal : stigma tufted. 



5. Alchemilla. Petals none. Stamens and pistils 1 - 4 : style lateral 



6. Agdiuonia. Petals 5. Stamens 12 -15. Pistils 2: style terminal. 



Tribe lit. DRYADEjE. Pistils numerous, rarely few or single, one-ovuled, becoming 

 dry achenia ; the calyx opeu, not fleshy in fruit. Petals present, usually conspicuous. 



7. Dryas. Petals and calyx-lobes 8 or 9. Stamens and carpels numerous : persistent 



styles becoming long plumose tails in fruit. 



8. Genin. Petals and calyx-lobes 5, the latter usually with 5 alternating small bractlets 



Stamens and carpels numerous : persistent styles becoming long plumos-' or hairy, x>i 

 naked and straight or jointed, tails. Radicle inferior. 



9. Waldsteinia. Petals and calyx-lobes 5 : small or no bractlets. Stamens numerous. 



Achenia 2 - 6 : styles deciduous from the base. Radicle inferior. 



10. Pibbaldia. Petals minute : stamens and achenia 5-10: otherwise same as Potentilla. 



11. Potentilla. Petals 5 (rarely 4), conspicuous. Calyx-lobes as many, and also with an 



alternating set of accessory lobes or bractlets. Stamens and achenia numerous ; the 

 latter heaped on a dry receptacle. Styles commonly more or less lateral, deciduous or 

 not enlarging in fruit. Radicle superior. 



12. Fragaria. Flower as in Potentilla. Receptacle much enlarged and pulpy in fruit. 

 Tribe IV. RUBBLE. Pistils numerous or several, 2-ovuled, becoming berry-like or 



drupelets in fruit ; the 5-cleft calyx not bracteolate, open, persistent or withering beneath 

 the fruit. Petals conspicuous. 



13. Dalibarda. Carpels 5 -10, in the bottom of the calyx, almost dry. 



14. Rub us. Carpels numerous, heaped on the receptacle. 



Tribe V. ROSEiE. Pistils numerous, one-ovuled, becoming achenia, contained in the 

 urn-shaped or globular and almost closed fleshy tube of the calyx, or hip : no bractlet3. 

 Petals conspicuous. 



15. Rosa. Character of the Tribe. 



Suborder III. POMEJE. (Pear Family.) 

 Calyx-tube thick and fleshy in fruit, including and combined with the 

 2-5 ovaries (forming a pome). Stipules free. 



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



16. Crataegus. Pome drupe-like, with 1-5 bony stones or kernels. Usually thorny. 



17. Pyrus. Pome containing 2 5 papery or cartilaginous carpels. 



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



18. Amelancbier. Pome usually of 5 carpels ; each becomes incompletely 2-celled by a 



projection from its back : otherwise as Pyrus. 



1. PRUNUS, Tourn. Plum, Cherry, &c. 



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

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

 with 2 pendulous ovules. Drupe fleshy, with a bony stone. — Small trees or 

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

 § 1. PRUNUS & CERASUS, Tourn. Drupe smooth, and the stone smooth or 

 somewhat rugged : flowers (usually white) from separate lateral scaly buds in 

 early spring, preceding or coetaneous with the leaves ; the pedicels few or several 

 in simple umbel-like clusters. — The Plums of the Old World have the leaves 



