Proceedings of the Ohio State Academy of Science 157 



1. Flowers solitary or in twos, appearing before the leaves; fruit vel- 



vety, stone compressed ; leaves ovate to round-ovate, abruptly 

 pointed ; terminal bud of twigs absent. P. armeniaca. 



2. Leaves mostly convolute in vernation; fruit usually large; stone 



more or less flattened ; terminal bud of twigs absent. 3. 



2 . Leaves conduplicate in vernation ; fruit mostly small ; stone mostly 



globose ; terminal bud of twigs present. 8. 



3. Leaves abruptly acuminate; drupe red or yellowish. 4. 



3. Leaves obtuse, acute, or gradually acuminate: drupe red or purple. 6. 



4. Calyx lobes entire, pubescent within; drupe globose; leaves ovate 



or obovate. P. americana. 



4. Calyx lobes glandular-serrate; drupe subglobose or oval. 5. 



5. Calyx lobes glabrous within; leaves oval or obovate. P. nigra. 



5. Calyx lobes pubescent on both sides; leaves ovate-lanceolate. P. 



liortulana. 



6. Leaves glabrous when mature, acute or acuminate. 7. 



6. Leaves pubescent beneath, not pointed, ovate or obovate. P. do- 



niestica. 



7. Leaves lanceolate; drupe red, thin-skinned, with little or no bloom. 



P. angustifolia. 



7. Leaves ovate; drupe dark purple with a bloom. P. allcghaniensis. 



8. Leaves glabrous; inflorescence umbellate; drupe with thick flesh, 



sour. P. cerasus. 

 8. Leaves glabrous, shining; inflorescence more or less corymbose; 

 drupe with thin sour -flesh. P. pcnusyli'auica. 



8. Leaves pubescent beneath at least on the veins; inflorescence um- 



bellate ; fruit sweet. P. avium. 



9. Fruit red or purple, astringent; leaves obovate or oval, abruptly 



acute or acuminate, thin ; glands on the petiole usually rounded or 



disc-like ; bark gray. P. virginiana. 

 9. Fruit dark-purple or black, sweet; leaves oval or obovate, acute 



or obtusish, thick ; otherwise much like the preceding. P. demissa. 

 9. Fruit dark-purple or black, sweet: leaves oval-lanceolate to ovate, 



acuminate or acute; glands on the petiole usually elongated and 



tooth-like ; bark black. P. scrotiiia. 



Plums and Apricot. 



*. Primus armeniaca L. Apricot. A small round-topped 

 tree with reddish bark. Drupe nearly smooth, short stalked, yel- 

 low, edible. Cultivated. 



I. Prunus americana M;arsh. Wild Plum. A shrub or 

 small tree with stunted thorn-like branches and thick black bark. 



