102 
++ Calyx-lobes mostly with bractlets: ovule solitary. 
Trine IV. Herbs, shrubs, or trees, with few to many 1-ovuled pistils becoming 
dry achenes.—POTENTILLEA. 
a. Trees or shrubs: styles elongated and plumoss in fruit: calyx imbricated, with- 
out bractlets (except in No. 8). 
6, Cercocarpus. Leaves simple, entire or toothed: small flowers axillary and 
solitary : calyx-tube long-cylindrical: petals none: carpels solitary, rarely 2. 
7. Cowania. Leaves entire or toothed: showy flowers short-peduacled and ter- 
minal: calyx-tube short and turbinate: petals 5: carpels 5 to 12. 
8. Fallugia. Leaves with linear lobes: showy flowers on long peduncles and some- 
what panicled : calyx-tube turbinate: petals 5: carpels numerous. 
b. Herbs: calyx valvate in bud, bracteolate: carpels few to many: stamens and 
achenes numerous, the latter heaped on a dry receptacle. 
9. Geum. Styles persistent and elongated after blooming, often plumose or jointed, 
strictly terminal, 
10. Potentilla. Styles not elongated after blooming, mostly deciduons, and com- 
monly more or less lateral. 
II. Ovaries inferior or inclosed in the calyx-tube. 
Trigg V. Prickly shrubs, with pinnate leaves: petals conspicuous: stamens nuimer- 
ous: pistils many, becoming bony achenes and inclosed in the globose or urn-shaped 
fleshy calyx-tube which resembles a pome.—ROSE, 
11. Rosa. The only genus. 
TRIBE VI. Trees or shrubs with stipules free from the petiole: carpels2 to 5, inclosed 
in and coalescent with the fleshy or berry-like calyx, in fruit becoming a 2 to several- 
celled pome.—POME. 
12. Pyrus. Pome containing 2 to 5 papery or cartilaginous carpels. 
13. Cratezegus. Pome drupe-like, with 1 to 5 bony stones: usually thorny. 
1. PRUNUS Tourn. (PLUM, CHERRY, ETC. ) 
Small trees or shrubs, with a deciduous bell-shaped or urn-shaped 
5-cleft. calyx, 5 spreading petals, 15 to 20 stamens, solitary 2-ovuled 
pistil, and a fleshy drupe (with bony stone) which is mostly edible. 
* Flowers from separate lateral scaly buds in early spring, preceding or coetancous with the 
leaves. 
+ Flowers several in umbel-like clusters : leaves ample: drupe oblong, smooth, and fleshy : 
shrubs or trees. 
1. P. Americana Marshall. (WILD YELLOW or RED plum.) A thorny tree 3 to 
12 m, high: leaves ovate or obovate, conspicuously pointed, coarsely or doubly ser- 
rate, very veiny, glabrous when mature: fruit nearly without bloom, roundish-oval, 
yellow, orange or red, 12 to 16 mm. in diameter, with the turgid stone more or less 
acute on both margins, or when cultivated with a larger fruit and flatter more broadly 
margined stone. —Common in the Atlantic States, and extending in Texas to the valley 
of the Concho, Var, MOLLIS Torr. & Gray has the leaves and pedicels pubescent, 
especially when young. Occurring sparsely on the San Antonio and its tributaries, 
where the fruit is said to be yellow and smaller than in the species ( Havard.) 
9. P, rivularis Scheele. (CREEK pLuM.) A smallshrub 6 to 18 dm. high, with the 
foliage of the last, but with fruit the size of a cherry, ora little larger, and cherry 
red.—Not uncommon on the Colorado and its tributaries and extending to the upper 
Guadalupe and the Leona. Said by Lindheimer to grow on the “banks of streams 
and margins of bottom-woods, forming thickets near the water, rarely on higher places.” 
The fruit is said to be excellent. 
