104 SYSTEMATIC J'OMOLOdY 



a family. I'oniologists are eunc'crnt'd with but four of these 

 tribes. 



150. Tribe Pomae, the pome-fruits. — The pomaceous plants in 

 the Kose Family are clistiiiguished by fiowei-s with few carpels, 

 mostly two to five, uhiually firmly united, and borne witliin an 

 urn-like depression in the enlarged summit of the flower-stem 

 with which it is also united, the whole forming a fleshy fruit. 

 All of the pome-fruits are trees or shrubs with small deciduous 

 stipules which are free from the petiole. 



There are twenty to thirty genera with several hundred 

 species of wide geographical distribution mostly in the north 

 temperate zone. Of these but two genera are of great impor- 

 tance in fruit-growing: namely, Pyrus, to which belong apples 

 and pears; and Cydonia, the quince. Four other genera are of 

 lesser importance ; ^lespilus, the medlar ; Eriobotrya, the loquat ; 

 ChjEnomeles, the Japanese quince; and Amelanchier, the june- 

 berry. The fruits of Crataegus, the hawthorns or thorn-apples, 

 allied to medlars in the structure of the fruit, are edible, and 

 several species offer possibilities for domestication, but none is 

 noW' cultivated in North America. 



KEY TO CULTIVATED GENERA OF POMACES 



Mature carpels bony Cratwgus (hawthorns and thorn-apples) 



Mature carpels papery or leathery. 



Pome with open top Mespilus (medlar) 



Pome with closed top. 



Ovules one in each cavity Amelanchier (juneberry) 



Ovules usually two in each carpel. 



Leaves deciduous Pyrus (apple and pear). 



Leaves persistent Eriobotrya (loquat). 



Ovules many in each carpel Cydonia (Quince). 



151. Tribe Prunese, the drupe-fruits. — In this tribe the ovary 

 is superior and is not inclosed in the calyx-tube at ma- 

 turity. The pistil becomes at maturity a drupe- or stone-fruit. 

 The style is terminal. The plants are trees or shrubs, with 

 alternate petioled mostly serrate leaves. The bark of all the 

 representatives of these drupe-fruits exudes a gum, and bark, 

 leaves, and seeds are very bitter and mostly contain small 

 quantities of prussic acid, sufficient in the leaves to poison 

 animals occasionally. There is but one genus, Prunus, to which 



