HERBACEOUS AND WOODY DICOTYLEDONS 405 



RUBUS (RASPBERRIES AND BLACKBERRIES) 



Habit and history. The raspberries and blackberries now 

 under cultivation had the same general origin and history as 

 that of the cultivated strawberry in that they have been derived 

 in almost every instance from wild ancestors. Thus, the com- 

 mon black-cap raspberries seem to have originated from chance 

 seedlings, possibly mutations, first discovered in Ohio in 1832 

 by Nicholas Longworth. The 

 red raspberries probably had 

 a similar origin from wild 

 ancestors in Canada and the 

 northeastern portions of the 

 United States. The culti- 

 vated blackberries have evi- 

 dently been developed from 

 the wild species of our own 

 country and came gradually 

 into use by the early settlers. 



Both raspberries and black- 

 berries are prickly shrubs with 

 simple or compound leaves 

 and with aerial stems, called 

 canes, which produce leaves 

 and buds for the first year 

 only. From these first-year 

 canes lateral buds develop the flowers and fruit of the second 

 season. After the formation of the fruit the canes die and are 

 replaced in many species by sucker shoots which spring up from 

 the roots. In the black raspberry vegetative reproduction takes 

 place by means of branches which bend over and take root, thus 

 giving rise to new plants (Fig. 75). 



Flowers and fruit. The flowers are either axillary and soli- 

 tary or are borne in clusters. They resemble the flowers of the 

 strawberry in being perfect and perigynous, with an enlarged 

 receptacle (Fig. 256, 6). There are five petals, many separate 

 pistils crowded on the receptacle, and numerous stamens. 



FIG. 256. Flower and fruit of the 

 blackberry and the rose 



a, 6, c, blackberry; d, e,f, rose 



