J. SMITH ON THE GENERA OF FERNS. 149 



39. Stenochl^na, J. Sm. 



(Acrostichi, sp. Auth. Lom arias, sp. Kaiilf. Wall. Willd. 

 Olfersise, sp. Presl.) 



Veins simple oi* forked, external ; venules parallel, their 

 apices exserted, forming cartilaginous serratures, or conniv- 

 ing and forming a thickened margin ; margin of the fertile 

 segments membraneous, revolute, indusiiform. 



Fronds pinnate, smooth, or sqiiamose, pinncB petiolated, arti- 

 culated with the rachis. Fertile pinnae linear revolute. Rachis 

 sometimes producing abnormal tripinnatijid sterile fronds. 



Examp. 1. S. longifolia, (Lomaria, Kaulf.) 2. S. sorbi- 

 folia, {Linn.) (Lomaria, Kaulf.) 3. S. scandens, {Linn.) 

 4. S. triquetra, QVall.) 5. S. spondicifolia, {Lomaria^ Wall.) 

 6. S. limonifolia, (Lomaria, Wall.) 7. S. heteromorpha, J. 

 Sm. {Lomaria, Jiliformis, A. Cunn. Lomaria propinquay 

 A. Cunn.) Illust. Schk. crypt, t. 106, 107. 



Obs. The distinct and peculiar aspect of the species form- 

 ing this genus evidently denotes them as forming a distinct 

 and very natural group, yet on setting their habit aside, it 

 becomes difficult to point out a good technical character to 

 distinguish them from the preceding genus, as also from the 

 following. Their habit and the indusiiform margin of the 

 fertile pinnae agree in many respects with Lomaria^ a 

 genus in the following tribe, which differs from the present 

 genus, by its having a special indusium not formed of the 

 revolute margin, as in Stenochlcena, but rising from a recep- 

 tacle a little within the margin. Some of the species of this 

 genus are remarkable for producing a third form of frond, so 

 unlike the usual forms, that, in the absence of good autho- 

 rity, it would be difficult to believe that it formed part of 

 the same plant. The rhizoma is creeping, and ascends 

 sometimes to a considerable height on trees, and producing 

 at the apex the usual form of fertile and sterile pinnate fronds, 

 which are sometimes two to three feet in length, while the 

 abnormal fronds are usually about three inches in length, 

 tripinnatifid, and barren; not unlike some multifid species of 



