PLACE AND NATURE OF ORIGIN 



163 



oldest existing phytomer perishes each year as a successive apical one 

 is formed (Fig. 450, b). 



Forms of Rhizomes. — Rhizomes are so numerous and important in 

 pharmacy that their characters call for special attention. They are 

 classed as short or elongated, the former term referring to those 



4J£. 



Forms of rhizomes: Fig. 447. Convallar\a, with annular roots: a, terminal bud. 448. Cimicifuga, 

 its cup-shaped stem-scars much elevated. 449. Podophyllum, its internodes elongated. 450. Poly- 

 ffona/um, its cup-shaped scars depressed. 451. /n's, its roots aggregated at one end. 452. Acorus, with 

 V-sbaped leaf-scars. 



the extreme length or shortness of which fall within certain fairly 

 defined and restricted limits; the latter, those which either possess an 

 indefinite extension, or the definite length of which is a great many 

 times their thickness. Terms indicative of their form and consistency 

 do not differ materially from those applied to other stems and to roots. 

 They are almost always sympodial. They are -s-ery subject to flatten- 



