2l6 PLANT ORGANS OR PARTS OF PLANTS. 



the ray flowers bear an epidermis papillose above, of 

 finely striated polygonal cells below. Glands are found 

 among the striated cells on the lower portion of the 

 ligula; within are several sm.all fibro-vascular bundles, 

 and an occasional oil or resin duct. The elongated disk 

 florets, their lower portion (Fruchknoten) enclosed in an 

 entire pappus, densely studded with resin glands below 

 and with numerous crystals of calcium in their elongated, 

 slightly thickened cells, possess a five-toothed corolla of 

 structure similar to that of the rays, but without papillae. 

 Resin glands and calcium oxalate crystals are frequent. 

 The united anthers are made up of regular polygonal some- 

 what thick- walled tissue, containing a yellow granular 

 matter. The peculiar thickening of these cell walls is 

 quite characteristic. The round, single-celled pollen 

 grains, 28 microns in diameter, show three distinct equi- 

 distant dilations and a surface covered with conical 

 papillae. 



The stigma is forked and bears cylindrical papillae. 

 The ovary is five-ribbed (in C. roseum ten), with a 

 minute fibro-vascular bundle and two or more resin 

 ducts in each, and, in the outer portion, crystals of 

 calcium oxalate. 



Powder. — The powder, if unadulterated with cur- 

 cuma, has a grayish-yellow color. That from the Per- 

 sian flowers is lighter than that from the Dalmatian. 

 Differential characters are difficult to find. The T- 

 shaped hairs seldom occur with the horizontal cell 

 attached. As they are more numerous on the stem and 

 leaves of the plant than on the flower, their frequent 

 appearance would indicate adulteration, which may be 

 confirmed by the presence of much fibro-vascular tissue 

 and a scarcity of pollen grains. The cell walls of the 

 anthers, at least of the Persian flowers, show peculiar 

 papillous thickenings, which are characteristic. The 

 papillae on the ligules of the ray flowers of C. roseum 



