GENUS ZINGIBER. 



779 



STARCHES OF ZINGIBERACE/E. 



Class, Monocotyledones. Order, Scitaminales. Family, Zingiberacese. 

 Genera represented: Zingiber, Hedychium, Curcuma. 



The family Zingiheracece includes 23 genera and about 315 species, chiefly tropical, and mostly 

 natives of Indian China. 



GENUS ZINGIBER. 



There are about 30 species o' Zingiber. Ginger is extensively cultivated throughout tropical 

 Asia, and also in many other tropical countries, particularly in Jamaica and nearby regions. The 

 rhizome of Zingiber officinale Rose, is the officinal ginger of the materia medica. The most esteemed 

 form is Jamaica ginger, which is probably a variety of Zingiber officinale, the rhizomes of which are 

 designated commercially black or white in accordance with whether the dark integument is intact 

 or has been scraped off. Starches from four sources were examined, as follows: (1) Z. offix^inale 

 Rose, the preparation being obtained directly from the rhizome from the Botanical Gardens of the 

 University of Pennsylvania; (2) a preparation made from ground ginger sold commercially as Ja- 

 maica ginger; (3) another preparation made from the white rhizomes sold as Jamaica ginger; 

 and (4) another preparation obtained from rhizomes in the materia medica collection of the Uni- 

 versity of Pennsylvania, marked Cochin ginger, which has been bottled for a period of perhaps over 

 50 years, and is regarded as a variety of Z. officinale. 



STARCH OF ZINGIBER OFFICINALE. (Plate 80, figs. 477 and 478. Chart 324.) 



The starch was prepared from the fresh rhizome obtained from the Botanical Gardens of the 

 University of Pennsylvania. 



Histological Characteristics. — In form the grains are simple with the exception of rare compound 

 grains consisting of two components. There are a few clumps, no aggregates, and no pressure 

 facets. The surface tends somewhat to irregularity, due 

 chiefly to small, rounded protuberances and nipple-like 

 projections, the latter especially at the proximal end. The 

 margin of the grain, particularly of the proximal end, may 

 be undulating owing to erosions. The most conspicuous 

 form is a flattened ovoid with a tendency for the whole 

 grain, particularly the proximal end, to be more or less 

 curved along the longitudinal axis. The proximal end 

 is usually more or less pointed, and sometimes this pro- 

 jection is very marked, particularly in grains that have 

 undergone erosion. This end may be so modified as to 

 form a very acute or a very obtuse angle, or all tran- 

 sitional angles. Some of the grains are dome-shaped, 

 triangular, oval, almost square, and in some there is an 

 approach to the clam-shell type. The grains are dis- 

 tinctly flattened, being usually about one-third as thick 

 as broad. In this specimen many grains showed more 

 or less marked erosion at the proximal end. 



The hilum is not usually visible, chiefly because of 

 its smallness and its extremely eccentric location, it being 

 situated at the apex of the small point that projects from the proximal end. 

 it is a small round spot, never fissured. Double hila are rare. 



The lamellw are very distinct, fine, and regular, and arranged in regular series running trans- 

 versely to the longitudinal axis as arcs of circles which are in all probability parts of continuous 

 rings. Near the hilum are two usually coarser and more distinct than the others. Occasionally those 

 near the distal end are larger and coarser than those in the middle of the grain, and there are more or 

 less variations in different parts. On a large grain the common number is about 57. 



I GV 

 S 



Chart No. 324. 



GV S T CI CA PA 



PS CI PA I 

 "" PCPS 



Curve of Reaction-Intensities of Starch of Zingiber 

 officinale. 



When it can be seen 



