196 NOTES ON NORTH BRAZILIAN GENTlANEiE. 



raliziug physiological phenomena, and causes and effects, from the ob- 

 servation of a few isolated facts. From the fact that the well-known 

 European parasites, such as OrobancJie^ Monotropa^ Cytinus, etc., are 

 deprived of leaves or other green parts, it has been laid down as a law 

 that this is the necessary consequence of parasitism on roots of living 

 plants. But already the discovery that Thedum^ BUnanthis, and 

 others with perfect green leaves, were nevertheless parasites, had de- 

 stroyed one part of the theory, and now we have the concun-ent testi- 

 mony of several careful collectors, whose attention has been specially 

 directed to 'the question, that Voyrias, which, under the above rule, 

 had been set down as parasites, are not so in fact, but are always to be 

 found on rotten wood or sticks, or amongst dead leaves, iu a state of 



decomposition. 



The species now known are numerous, even after we exclude a Bur- 

 manniacea^ which may here and there have insinuated itself among 

 those described in consequence of its similarity of habit. They have 

 been well distributed into sections by Grisebach and others, although 

 here and there the characters may require some correction. The an- 

 thers, for instance, in Zeiphaimos are very often connate, and the fila- 

 ments of LeiantJiostemoriy are usually, if not always, very short ; and it 

 is difficult to agree with Miquel in the propriety of raising these sec- 

 tions into the rank of genera, thus breaking up the most natural group 

 we have among Gentia?ieee, 



■m 



The Voyri(e gathered by Mr. Spruce are all uniflorous. I find 

 among them but two which appear to be already published. One, the 

 common V. unijlora^ Lam., was found by him at Caripi, near Para, on 

 bare shady places in the forest, in August, 1849, and again in the 

 woods on the Eio Uaupes, in January, 1853. In the latter place he 

 gathered also a couple of specimens of a pale sulphur-colour, which he 

 thought might be distinct, but I can find no character to separate 

 them. The other appears to be the F.Jlavescem, Griseb., remarkable 

 for the obtuse lobes of the corolla, and for the two rather large ovate 

 scales (or glands ?) attached to the ovary, not quite at the base, as de- 

 scribed by Grisebach, but about a quarter up its sides. My specimens 

 differ also slightly from Grisebach's character in the tube of the corolla, 

 shorter iu proportion to the lobes, and in the anthers, which are con- 

 nate, with the cells obtuse above, and produced into a rather blunt 

 point below. Tct they belong probably to the same species. Mr. 



