RUBUS 301 



cultivated for its fruit, contain about 3 per cent of amygdalin (see 

 Almond). 



The fruit of Prunus serotina consist of small, black drupes, which 

 when ripe are sweet, slightly acid and astringent. They are used in 

 making a wine and might be employed in other preparations of wild 

 cherry. 



Literature. Bastin, Amer. Jour. Pharm., 1895, pp. 435 and 595; 

 Stevens, Proc. A. Ph. A., 1896, p. 215; Ibid., 1899, p. 184; ibid., 

 1900, p. 207; Power and Moore, Trans. Jour. Chem. Soc., 1909, 

 p. 243; Nichols, Jour. A. Ph. A., 1917, 6, p. 540. 



RUBUS. Blackberry Bark. The bark of the rhizome of the 

 perennial shrubs Rubus villosus, R. nigrobaccus and R. cuneifolius 

 (Fam. Rosacse). R. villosus occurs in dry fields from Canada to 

 Virginia and as far west as Kansas. R. allegheniensis (R. nigrobac- 

 cus) or common blackberry occurs in woods in the eastern and 

 central United States and extensively cultivated. R. cuneifolius 

 is the sand blackberry and is found in sandy woods from New York 

 to Florida and west to Missouri and Louisiana. The bark should be 

 collected in spring or autumn and dried. 



Description. In flexible, transversely curved or slightly quilled 

 pieces 4 to 20 cm. in length, 3 to 5 mm. in diameter, bark 0.2 to 2 mm. 

 in thickness; outer surface light brown, longitudinally wrinkled, 

 with few root-scars, periderm frequently exfoliated; inner surface 

 light brown, coarsely longitudinally striate; fracture short, fibrous, 

 surface light brown, with oblique radiate wedges of bast; odor slight; 

 taste astringent. 



Inner Structure. The capillary lateral roots possess a thin epi- 

 dermis with numerous hairs; a homogeneous cortex and an endoder- 

 mis of thin-walled cells; a pericambium; a stele that is triarch and 

 minus a pith. In primary roots the pericambium gives rise to several 

 layers of cork, which replace the peripheral tissues from endodermis 

 to epidermis; a secondary cortex consisting of starch-bearing paren- 

 chyma; the stele consists of a compact mass of porous tracheids, 

 thick-walled parenchyma and a few wood fibers, separated by a 

 cambial layer from the leptome, which consists of several strands of 

 sieve and thin-walled parenchyma. In thick roots a stereome, in 

 the form of isolated strands, occurs between the parenchyma of the 

 secondary cortex and cork. Rosette aggregates of calcium oxalate 

 occur in the secondary cortical parenchyma. Holm, Merck's Report, 

 1910, p. 218. 



Powder. Light brown; bast fibers numerous, long, thick-walled, 

 lignified; calcium oxalate in rosette aggregates from 0.025 to 0.035 



