﻿Trees of New York mate 369 



short filaments and elongate clavate anthers cro\vned with a pilose, truncate, 

 connective; pistillate heads green tinged Avith red, solitary and terminal or in 

 terminal spicate clusters, the lateral heads then embracing the peduncle at 

 maturity; sepals 3-6, romided; petals 3-6, acute, longer than the sepals; 

 staminodia present; pistils 3-6, superior subtended at the base with per- 

 sistent straight hairs, with long curved styles stigmatic on the ventral side. 

 Fruit a subgobose head, consisting of many clavate, crustaceous 1-seeded 

 achenes tipped with the persistent styles and subtended at the base with bristly 

 hairs; seed oblong, albuminous. 



THE PLANE TREES. Genus PL AT ANUS (Toiirn.) L. 



For distribution and characters of the genus, see description of 

 the family. 



ROSE FAMILY. ROSACEAE 



Trees, shrubs and a few herbs numbering upwards of fifteen 

 hundred species, grouped in about ninety genera. Rosaceous 

 plants are widely distributed throughout the temperate regions of 

 the world and include many of our important fruit trees such as 

 the Apple and the Pear. Ten genera are represented by arbores- 

 cent species within the United States. 



Sap watery. Branch! cts terete. Buds scaly Leaves alternate or rarely 

 opposite, simple or compound, deciduous or persistent, stipulate. Flowers 

 perfect, generally showy; calyx-tube 5-lobed; petals 5 and separate, or want- 

 ing; stamens numerous, distinct, inserted with the petals on a disk lining 

 the calyx-tube; anthers small, -celled, longitudinally dehiscent; pistils 

 1-many, distinct or miited and combined -u-ith the calyx-tube; ovules 1-2 in 

 each cell. Fruit various. 



KEY TO THE GENERA page 



1. Ovary inferior. 2-.5 celled, adnata to the enlarged calyx-tube (or receptacle); 



fruit a pome 2 



1. Ovary superior, 1-celled; fruit a drupe Prunus 371 



2. Mature carpels papery or soft-cartilaginous at maturity 3 



2. Mature carpels hard and bony at maturity Crataegus 371 



3. Cells of the ovary as many as the styles, without false partial partitions 



Pyrus 3 9 

 3. Cells of the ovary twice as many as the styles, with false partial partitions. . 



Amelanchier 370 



THE APPLES AND PEARS. Genus PYRUS (Tourn.) L. 



Small or medium sized trees of the northern hemisphere, chiefly 

 of the Old World. Some forty species are included, of which five 

 are native to North America, four in the eastern states and one 

 on the Pacific Slope. In addition several introduced species have 

 become widelv naturalized. 



