236 r>IFFERENTIATION AND SPECIFICITY OF STARCHES. 



Dorstcnia hrasiliemis Linn.; Radix contrajervce Moroen. (Arlocarpacew.) Dry rool-siack. Grains 

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

 to 7m- 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-stock. Grains spherical or rounded- 

 oval; the larger ones hollow; Size about 7fi. 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 Polygonacece 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 Leguminosce. 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 

 hiliun. Many grains have a swollen appearance. 



Polygonum viviparurn Linn. {Polygonacece.) Dry root-slock. Grains rounded, rounded-triangular, 

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

 curved, and of ten with protruding corners or wart-hke process; broad ones compressed; from 

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

 Among the above are some doublets. 



Polygonum bistorta Linn.; 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 

 17/u, width 11/i. 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/i. Little starch. 



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

 ones with a cavity. Size about Ifi. 



Polygonum convolvulus Linn. (Polygonacece.) Dry root. Grains spherical to oval. Size about 8/t. 

 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/i, width 11//. 

 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 ones 

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

 24yu. Among the above some doublets are observed. 



Rumex crispus Limi. (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 slit. Size about 20 to 32/i. 



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 lO^i. Among the 

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



Rumex 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 compomad grains of few equal or imequal components (see type 15). 



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

 slightly angular; the larger ones have a central cavity. Size about 9ju. Also some compound 

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



