52 ARKIV FÖR BOTANIK. BAND 1. 



in question, as the original description by Poiret is impos- 

 sible to be applied.^ 



I therefore need only add a few words in order to make 

 clear the difference between this species and Tr. sphenoides, 

 which ranks very near it. The descriptions in Hook, and 

 Bak., Syn. Fil., ed. 2, p. 74, and in Flora Brasil., fasc. 23, 

 p. 276, are insufficient for this purpose, because these two 

 species are heteromorphous in the same degree, and only the 

 venation is to be depended on, if seen when magnified. Nei- 

 ther of these two can in every case be called »flabellate» as 

 to the venation, as Van den Bosch, Synopsis Hymenophylla- 

 cearum, p. 379, states for them both (and for :>>Tr. pusillum» 

 too). In a fertile frond of all species (see fig. 23 — 29) there 

 is a strong midrib to the involucre, and even in Tr. puncfa- 





Fig. 30. A Trichonianes punctntum (Poir.) Hook, et Grev. emend., fertile 



and sterile fronds from Cuba, Wright n. 952 (ex parte) and from French 



Guiana, Sagot (in 1850). — B Trichonianes lineolatiim (V. D. B.) Hook., 



fronds of various development from Cuba, Wright n. 952 (ex parte). 



turn. Yet, in a sterile frond of both of these (and in other 

 species of the sjihcnoides-gvowi^, for instance Tr. fontanum, 

 fig. 26) the veins all rise near the base of the frond; and 

 the upper half of the costa being of the same appearance as 

 all stronger lateral branches, the veins in this state may be 

 called »radiating as in a fan» (Hook, and Bak., Syn. Fil., 

 ed. 2, p. 72). 



^ The illustration in Hook, et Grev., t. 23G, is excellent as to the plant, 

 drawn in natural size; the enlarged fronds on the same plate are not quite 

 correct, probably representing an undeveloped stage, or taken^from Tr. sphe- 

 noides Kze. 



