a A E E 
DENM o LAM a 
of Lathrea Squamaria, $c. 409 
** Radice nititur albicante, magna, succosa, fragili, compactili squa- 
marum congerie:” yet it will scarcely be contended that his **miro 
sane nature artificio elaborata" refers to anything beyond their 
exterior appearance. Linneus, Withering, Willdenow, &c., also 
call them roots; and the able author of Vegetable Physiology * 
considers them as **scaly appendages to the roots." Sir J. E. 
Smith in English Botany (vol.i. tab. 50.), and in his Introduction 
to Botany (chap. xii.), also calls them roots, though he was sub- 
sequently led (English Flora, vol. iii. p. 128.), from the analogy 
of this genus to Melampyrum, to refer them to their true cha- 
racter of a subterranean herbage. He seems nevertheless, 
incorrectly I presume, to confound them with the bracteas of 
the flowering branches, which he distinctly calls leaves. The 
idea of their being roots, though erroneous, was venial enough 
from their underground situation, and is probably as old as 
a knowledge of the plant itself. It has perhaps been per- 
petuated among botanists by a remark made by Linnzus, and 
alluded to by Mr. Brown in his very luminous paper on the 
Raflesia: (Linn. Trans. vol. xiii. p. 226.), “that the whole 
tribe of parasitic plants are distinguishable by the imperfect 
development of their leaves, and the entire absence of green 
colour." The learned author last quoted justly observes that 
plants parasitic on roots are chiefly thus distinguishable. This 
rule however is not universal, an exception being found in the 
genus Cuscuta ; which, after the decay of its original root, has 
no connection whatever with the earth, but is nourished and 
supported solely by radicles fixed upon the stems of other plants. 
Many if not all of the foreign species of Cuscuta have a similar 
economy, and are destitute of leaves and of green colour; in- 
deed I know of no plant without true leaves that is green. I 
* No. XIV. of the Treatises published by the Society for the Diffusion of Useful 
Knowledge, p. 29. col. 2. 
362 p am 
