372 TJie New York State College of Forestry 



imier scales accrescent. Flowers perfect, regular, showy, borne in axillary 

 umbels or corymbs or in terminal or axillary racemes; calyx-tube inferior, 

 5-lobed, the lobes imbricated iii the bud; petals 5, white, spreading, inserted 

 with the numerous stamens on the calyx-tube ; filaments filiform, free, bearing 

 oval 2-celled anthers ; pistil solitary, consisting of a simple 1-celled ovan' 

 terminated by an elongated style and capitate stigma. Fruit a 1-seeded 

 drupe; flesh thick and pulpy or dry and thin; pit bony, compressed, smooth, 

 rugose or patted; seed solitary, pale brown, exalbuminous ; cotyledons fleshy. 



KEY TO THE SPECIES page 



1. Ovary glabrous; pit smooth or shallowly sculptured 2 



1. Ovary velvety-tomentose P. Persica 265 



2. Flowers in racemes terminating leafy branches 3 



2. Flowers umbellate or corymbose ! . . 4 



3. Leaves oblong, rather thick, crenate-serrulate with incurved teeth 



P. serotina 245 

 3. Leaves chiefly obovate, thin, sharply serrate, the teeth somewhat spreading . . 



P. virgin! ana 247 



4. Flowers in axillary umbels appearing before or with the leaves 5 



4. Flowers in terminal corymbs appearing after the leaves P. Mahaleb 253 



5. Leaves conduplicate in the bud; fruit without ventral groove; stone globose 



or subglobose 6 



5. Leaves convolute in the bud ; fruit usually with a ventral groove ; stone com- 

 pressed 8 



6. Leaves ovate, oval or obovate; petals 3-f of an inch long 7 



6. Leaves oblong-lanceolate; petals less than g of an inch long 



P. pennsylvanica 249 

 7. Leaves membranous, pubescent beneath at least on the veins; fruit generally 

 sweet; inner accrescent scales of flower-buds ligulate and spreading at 

 blossom time P. avium 255 



7. Leaves semicoriaceous, glabrous; fruit sour; inner accrescent scales of flower- 



buds not ligulate, ascending at blossom time P. Cerasus 257 



8. Leaves ovate to obovate; fruit more than § of an inch in diameter 9 



8. Leaves oblanceolate to narrowly obovate ; fruit ^ of an inch or less in diameter 



P. instititia 251 



9. Umbels several flowered. 10 



9. Umbels 1-2 flowered P. domestica 263 



10. Leaves crenulate-serrate; calyx-lobes glandular-serrate P. nigra 259 



10. Leaves sharply-serrate; calyx-lobes entire P. americana 261 



PULSE OR PEA FAMILY. LEGUMINOSAE 



An extremely large family of some four hundred and fifty 

 genera and seven thousand species including trees, shrubs, woody 

 vines, and herbs, ^videly distributed through the tropical and tem- 

 perate regions of the world. Many are valuable timber trees while 

 others are important forage crops or are otherwise valuable to 

 man. In addition to the many herbaceous and shrubby forms, 

 lliere are seventeen genera which are represented by arborescent 

 forms in the United States. 



Leaves alternate, usually conipoiuul, stipulate. Flowers papilionaceous or 

 sometimes regnlar; stamens 10 (occasionally 5 or many), monadelphous, 

 diadelphous, or rarely distinct; pistil simple, superior, solitary. Fruit a 

 legume. 



