of LathrcEa Squamaria, ^c. 409 



*' Radice nititur albicante, magna, succosa, fragili, compactili squa- 

 marum congerie:" yet it will scarcely be contended that his ^^tniro 

 sane natura artificio elahorata" refers to anything beyond their 

 exterior appearance. Linnaeus, 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 Linnaeus, and 

 alluded to by Mr. Brown in his very luminous paper on the 

 Rafflesia {Linn. Trans, vol. xiii. p. 236.), " 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 DiiFusion of Useful 

 Knowledge, p. 29. col. 2. 



3 G 2 am 



