.228 



PERNS : BRITISH AND FOREIGN. 



116. HEMIDICTYUM, Presl 



Vernation fasciculate, erect. Fronds pinnate, 10-14 feet long ; 

 pinnse 1-2 feet long, 3-5 inches wide. Veins forked ; venules 

 parallel till near the margin, then anastomosing and reticulated, 



Genus 1 16. Portion of fertile pinna, under side. No. l. 



-combined by a transverse, continuous, marginal vein. Sporangia 

 produced on the superior side of the parallel veins, constituting 

 unilateral, linear sori. Indusium plane. 



1. H. marginatum, Presl ; Hook. Gen. Fil. t. 55 A. Asple- 

 nium marginatum, Linn. (Plum. Fil. t. 106) ; Hook. 

 Fil. Exot. t. 73 ; Lowe's Ferns, 5, t. 53. Diplaziurn 

 giganteum, Hort. Linden. Tropical America. 



117. CETERACH, Willd. ; /. 8m. 



Vernation fasciculate, erect, csespitose. Fronds 2-12 inches 

 long, sinuose-pinnatifid or pinnate, the under side densely squa- 

 mose. Veins- forked, anastomosing. Sporangia unilateral, 

 protruding through the dense squamae, forming oblong sori. 

 Indusium obsolete. 



