298 ORDER XLIV.— ROSACEA. 



i. Flowers in spikes Sanguuorla, 9 



Flowers in umbels Frunus, 2 



Flowers in racemes Cera-ncs, 4 



5. Ovaries 2—6 6 



Ovaries more than 6 9 



6. Leaves simple, undivided Spiroea, 5 



Leaves lobed or compound 7 



7. Flowers white Gillenia, 6 



Flowers yellow 8 



8. Flowers on a scape Waldsteinia, 8 



Flowers on a peduncle Agrimonia, 10 



9. Flowers yello-«' Potentilla, 11 



Flowers not yellow 10 



10. Eeceptacle dry Geum^ 7 



Eeceptacle fleshy 11 



11. Carpels inclosed by the receptacle Roi^a, 14 



Carpels imbedded in the receptacle Fi agnHa, 13 



Carpels pulpy liubus. 13 



12. Thorny shrubs Crategus, 15 



Unarmed shrubs or small trees 13 



13. Flowers in racemes Amelanchier, 17 



Flowers not in racemes Pyrus, 16 



Sub-Order L— CHRYSOBALA'NE^. 

 Calyx inferior. Petals and stamens more or less irregular. 

 Fruit a drupe. 



Genus 1.— CHRYSOBAL'ANUS. L. 11—1. 

 (From the Greek diriisos, gold, and Valanos, an acorn, in reference to its yellow fruit.) 



Calyx 5-eleft, persistent, campanulate, with nearly equal seg- 

 ments. Petals 5. Stamens numerous, those next the ovary 

 usually shortest and sterile ; ovary sessile ; ovules 2. Fruit a 

 drupe, with very little pulp, 1-seeded. Shrubs with flowers iu 

 terminal or axillary paniculate cymes. 



1. C. oblongifo'lius, (Mich.) Stem slender, prostrate, branching. 

 Leaves nearly sessile, oblong, or lanceolate-oblong, slightly crenulate, 

 glabrous, or tomentose beneath. Flowers small, terminal. Petals 

 nearly round. Fruit oblong, about 1 inch in length. — White. '^ . May 

 — June. Geo. and Ala. 1 — 2 feet. 



Sub-Order II.— AMYGDA'LE.E. 

 Calyx inferior. Fruit a drupe, 1-seeded. Bark yielding 

 gum. 



Genus II.— PRU'NUS. Tom-n. 11—1. 

 (Ancient name of the Plum.) 



Calyx 5-parted, somew^hat urceolate. Petals spreading, un- 

 guiculate. Stamens numerous. Ovary with 2 pendulous 

 ovules, glabrous. Fruit an ovate drupe, fleshy, with a com- 

 pressed nucleus, having grooved margins. Small trees and 

 shrubs. Leaves with a convolute vernation, senate. Flowers 

 usually appearing before the leaves. Plum, 



