118 
xxvn. rosacea: amtgdalea:. [ Primus . 
8. Potentilla. Achenes numerous, on a dry flat receptacle. Calyx 
double. 
9. Sibbaldia. Achenes 5 — 10, on a minute dry receptacle. Calyx 
double. 
Tribe 3. Sangcisorbiiee. Achenes 1 — 2, enclosed within the dry 
calyx-tube. 
* Style from near the base of the achene. 
10. Alciiemilla. Petals 0. Calyx double (8-cleft). Stamens 1 — 4. 
** Style terminal. 
11. Sanguisorba. Petals 0. Calyx single (4-cleft), -with 2 — 3 external 
bracteoles at its base. Stamens 4. Stigma capitate. 
12. Poterium. Petals 0. Calyx single (4-cleft). Flowers usually 
monoecious. Stamens many. Stigma tufted. 
13. Agrimonia. Petals 5. Calyx single (5-cleft), without external 
bracteoles. 
Tribe 4. Rosid/K. Petals 5. Achenes numerous, enclosed within the fleshy 
calyx-tube, which is contracted at the orifice. 
14. Rosa. 
Sub-Ord. III. Pome.e. Petals several. Carpels united and adhering by 
their back to the calyx-tube, thus resembling an inferior fruit. Stipules free. 
15. Mespilus. Calyx-segments large, foliaceous. Petals large, roundish. 
16. Crat.egus. Catyx- segments small. Petals large, roundish. Cells 
of fruit bony. 
17. Cotoneaster. Calyx-segments small. Petals small, erect. 
18. Pyrus. Calyx-segments small. Petals large, roundish. Cells of 
fruit cartilaginous. 
Sub-Ord. I. AMYGDALEiE. Cal. inferior, deciduous. Ovary 
solitary, superior. Style 1, terminal. Fruit a solitary drupe, 
with one or two seeds suspended from the top of their cell. 
Trees or shrubs with simple leaves and stipules free from the 
petiole. All the parts abound in Prussic acid. (Gen. 1.) 
1. Prunus Linn. Plum and Cherry. 
Cal. 5-cleft. Pet. 5. Nut of the drupe smooth, or furrowed 
at the margin. — Named irpowg in Greek, according to Theo- 
phrastus. 
* Flowers 1 or 2 together, on short pedicels. Fruit covered with bloom. 
Young leaves convolute. Prunus D C. 
1. P .communis Huds. ( common P.) ; pedicels solitary or in 
pairs, leaves elliptic or ovate-lanceolate somewhat downy be- 
neath especially when young. — a. spinosa; pedicels glabrous, 
leaves at length glabrous, branches spinous. P. spinosa L. : 
E. B. t. 842. — fi. insititia ; pedicels and under side of the 
leaves pubescent, branches slightly spinous. P. insititia L. : 
