CHAPTER XXVI 



ROSACEA (Rose Family) 



The Rosacese are well represented m North Temperate 

 climates. There are" about 1,200 species within 65 genera. 

 The most important genera from the crop standpoint are 

 Rubus (raspberry, blackberry and dewberry), and Fragaria 

 (strawberry) . Other genera of importance or of interest are 

 Spircea, an ornamental shrub, Potentilla (five-finger or cinque- 

 foil), Cercocarpus (mountain mahogany), and Rosa (rose). 



Leaves. — The leaves are alternate, either simple (as in 

 some Rubus species), or compound (strawberry, rose). 

 There are two rather prominent stipules, free from or adher- 

 ent to the petiole. 



Inflorescence.— There are several different kinds of flower 



clusters in the family. It is a terminal corymb (flat-topped 



raceme) in Opulaster, either racemose, 



cymose, corymbose or paniculate in SpircBu, 



terminal or axillary and soHtary, racemose 



or paniculate in Rubus, and corjnnbose or 



racemose in the strawberry. It is interest- 



FiG. i46^Fiorai ing to notc the great number of different 



diagram of Rubus. gorts of iuflorescences in this one family, and 



{After Wossidlo.) . . , , , ^ ., . , . , 



contrast it with the mustard family, m which 

 the raceme is the one prevailing type, or with the carrot 

 family in which the umbel is, with the exception of one 

 genus, the only type, or with the sunflower family, all mem- 

 bers of which have a head inflorescence. 



Flowers. — The flowers (Fig. 146) are regular, and usually 

 perfect. In some cultivated strawberries imperfect flowers 

 348 



