236 DIFFERENTIATION AND SPECIFICITY OF STARCHES. 



Dorstenia brasiliensis Linn.; Radix contrajervce Moreen. (Artocarpacece.) Dry rool-slock. — Grains 

 spherical, usually more or less angular; the larger ones have a small central cavity. Size 6 

 to In- The cells are filled with starch. Some of the grains are simple; the majority, how- 

 ever, are the separated-grains of compound ones (see type 16). 



Parietaria diffusa Mert. and Koch. (Urticacece.) Dry root-slock. — Grains spherical or rounded- 

 oval; the larger ones hollow; Size about 7/li. Among the above are some compound grains 

 of few, equal components (see type 14). Generally poor in starch. 



Polygonacece. Underground parts. — Since the seeds of PolygonacecB contain centric starch-grains, it 

 was desirable to examine the structure of the grains from other parts of the plant. Although 

 a number of roots and root-stocks were examined, the question could not be definitely decided. 

 In the analogous structure and in the frequent occurrence of a similar median slit, the grains 

 resemble those in the seeds of Leguminosw. They belong, however, to another type, as is 

 particularly illustrated by the compound grains. Very often small particles are cut off from 

 simple grains; and the large components sometimes show a distinctly eccentric, spherical 

 hilum. Many grains have a swollen appearance. 



Polygonum viviparum Linn. {Polygonacece.) Dry root-stock.— Gv&\ns rounded, rounded-triangular, 

 oval, oblong, elliptical, pear-shaped, or reniform, frequently irregular, occasionally somewhat 

 curved, and often with protruding corners or wart-like process; broad ones compressed; from 

 the narrow aspect they have a central cavity or a distinct longitudinal slit. Size about 14yu. 

 Among the above are some doublets. 



Polygonum bistorta Limi.; Radix bistortce. {Polygonacece.) Dry root-stock. — Grains rounded, rounded- 

 triangular ; oval, reniform, pear-shaped, rod-shaped or irregular, occasionally curved, frequently 

 with papillary protuberances on the circumference; the broad ones compressed; one-quarter 

 to as broad as long; many have a longitudinal slit or a large central cavity. Length about 

 17m, width 11^. Among the above are some doublets consisting of frequently elongated, 

 equal halves. The simple and the compound grains resemble those of Polygonum viviparum. 



Polygonum alpinum All. {Polygonacece.) Dry rootlets of young shoots. — Grains rounded to oblong, 

 elliptical, sometimes reniform or irregular; the broad ones compressed; the larger ones have a 

 cavity. Size about 9/u. Little starch. 



Polygonum aviculare Linn. {Polygonacece.) Dry root. — Grains spherical or rounded-oval; the larger 

 ones with a cavity. Size about 7^. 



Polygonum convolvulus Linn. {Polygonacece.) Dry root. — Grains spherical to oval. Size about 8^. 

 Poor in starch. 



Rumex obtusifolius; Radix lapathi acuti. {Polygonacece.) Dry root. — Grains oval, rounded-triangular, 

 elliptical, lanceolate or lanceolate spindle-shaped; one margin frequently more convex than 

 the other, or even somewhat curved; one-third to as broad as long; not at all or slightly 

 compressed; some grains have a longitudinal slit. Length about 16 to 20^, width ll/i. 

 Lamellae and hilum invisible; the latter is probably toward the thicker end. 



Rumex sanguineus Linn. {Polygonacece.) Dry root. — Grains rounded to lanceolate with either blunt 

 or pointed ends; frequently with one strongly convex and one straight or slightly concave 

 margin; sometimes triangular and irregular; 5 to 6 times as long as broad; the broad oiaes 

 slightly compressed; from the narrow aspect there is a distinct longitudinal slit. Size 20 to 

 24ju. Among the above some doublets are observed. 



Rumex crispus Linn. {Polygonacece.) Dry root. — Grains oval, oblong, elliptical, pear-shaped, very 

 often triangular or somewhat reniform with elevated ridges, often irregular, with either blunt 

 or pointed angles; the broad ones distinctly compressed; from the narrow aspect the majority 

 have a longitudinal sUt. Size about 20 to 32^. 



Rumex acetosa Linn. {Polygonacece.) Dry root-stock. — Grains spherical to oblong and conical; the 

 larger ones with a cavity nearly the same shape as the grains. Size about lOju. Among the 

 above are compound grains of few, usually unequal, components (see type 15). 



Rum£X maritimus Linn. {Polygonacece.) Dry root. — Grains rounded, oval, oblong, conical, the 

 broad ones slightly compressed; some grains have a narrow slit-like cavity. Among the 

 above are some compound grains of few equal or unequal components (see type 15). 



Rumex arifolius All. {Polygonacece.) Dry root-stock. — Grains spherical or rounded-oval, sometimes 

 shghtly angular; the larger ones have a central cavity. Size about 9/1. Also some compound 

 grains of few ecjual or unequal components (see type 14). 



