690 SCIENTIFIC AND APPLIED PHARMACOGNOSY 



with short roots or circular root scars, and occasionally having the 

 cork more or less abraded, showing a grayish-white cortex; inner 

 surface of the longitudinal pieces, either flattened or shallow, light 

 brown or grayish-brown, longitudinally striate and showing a more 

 or less distinct, dark brown cambium; fracture tough, horny and 

 somewhat uneven; inner surface light brown, showing a distinct 

 cambium and numerous large resin canals in both the xylem and 

 cortex; odor distinct, aromatic; taste sweetish, aromatic, slightly 

 acrid and pungent. 



Inner Structure. Rhizomes occasionally show the characteristic, 

 uniseriate hairs of the epidermis (Fig. 304) ; periderm usually narrow, 

 consisting of somewhat rectangular, thin-walled brownish cells; 

 cortex of inulin-containing parenchyma, the inner layers having 

 radial strands of phloem, consisting of leptome and parenchyma, 

 separated by broad medullary rays, containing spheroidal resin 

 canals (Fig. 304), the latter from 0.100 to 0.200 mm. in diameter, 

 the canals being lined with thin-walled epithelial cells; cambium 

 distinct ; xylem consisting of radiating wedges, composed of numerous 

 parenchyma cells and a few tracheae and wood fibers, separated by 

 broad medullary rays, interspersed with resin canals similar to 

 those in the cortex ; pith composed of inulin-containing parenchyma. 



In thick rhizomes, the xylem occurs in a broad continuous ring 

 consisting of numerous, thick-walled and strongly lignified wood 

 fibers, surrounding the tracheae, and in the cortex there is a strong 

 development of bast fibers, in the form of semi-circular groups, out- 

 side the strands of leptome. 



The roots show a similar structure to the rhizome, but the primary 

 tracheaB are associated with elongated thin-walled, lignified cells, 

 having reticulate perforations. 



In the intercellular spaces, between the parenchyma cells, occur 

 occasionally a yellowish-brown or brownish-black carbon-like sub- 

 stance, termed phytomelane. For further discussion of this subject, 

 with illustrations, consult Kraemer's Applied and Economic Botany, 

 pp. 258-261. 



Powder. Very light brown; on boiling with water it emits a 

 distinct aromatic, pepper-like odor, distinguishing it from bella- 

 donna; inulin (Fig. 304), in parenchyma cells, mostly in the form 

 of separate, irregular, colorless granules, varying from 0.010 to 0.030 

 mm. in diameter; fragments of yellowish-brown or reddish-brown 

 resin masses; tracheae having narrow lumina and large elliptical 

 perforations, occasionally bordered pores; wood fibers very narrow, 

 strongly lignified and marked by numerous simple pores; fragments 



