Dewberry \Dew"ber`ry\, n. (Bot.)
   (a) The fruit of certain species of bramble (Rubus); in England, the fruit of R. c[ae]sius, which has a glaucous bloom; in America, that of R. canadensis and R. hispidus, species of low blackberries.
   (b) The plant which bears the fruit.

Feed him with apricots and dewberries. --Shak.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Blackberry \Black"ber*ry\ (bl[a^]k"b[e^]r*r[y^]), n. [OE. blakberye, AS. bl[ae]cberie; bl[ae]c black + berie berry.]

The fruit of several species of bramble (Rubus); also, the plant itself. Rubus fruticosus is the blackberry of England; R. villosus and R. Canadensis are the high blackberry and low blackberry of the United States. There are also other kinds.

Source: Webster's Revised Unabridged Dictionary (1913)