LECT. IV.] THB ROOT. TUBERS. 151 



year; but there are always two or more tubers in 



a state of advancement towards perfection, and 



as many in that of decay. Pile-wort, Ranunculus 



Jicaria, affords the best example of this form of 



tuber : vide fig. r, in which 1. 1. indicates the 



more recent tubers ; 2. 2. those in a state of decay. 



. 3. The Fingered tuber (Tuber digitatum) (fig.*) 



receives its name from 

 the tubers resembling 

 fingers. In Satyrium 

 albidum, the plant 

 exhausts two tubers 

 in one season; see 

 fig. s, in which b. b. 

 represents a pair of 

 old tubers, the origin 

 of the existing plant ; 

 a. a pair of tubers for that of the next year, 

 with a still younger pair attached to them : c. c. 

 are the real roots of the plant. 



4. The Palmated tuber (Tuber palmatum) (fig. 



t) also receives its 

 name from its form, 

 which somewhat re- 

 sembles the human 

 hand. There are 

 rarely more than two 

 palmated tubers con- 

 joined, as in Orchis 



