136 



PEENS :- BiaTISH AND FOREIGN. 



63. MEKISCIUM, Schr^. 



♦ 



Vernation fasciculate and decumbent, or uniserial and sar- 

 mentose. Fronds pinnate, rarely simple, 1-8 feet iigh. Pri- 

 maury veins costaeforni, pinnate ; each opposite pair of venules 



Fort<cn of mature fiond. No. 4. 



angularly or arcuately anastomosing and sporangiferons, pro- 

 ducing from their junction an excurrent, free, sterile vi inlet. 

 Eecepiades medial, linear, continued across the junction of the 

 venules, foi-ming arcuate, transverse sori. Sporangia in some 

 species pilose. 



* Fronds simple. 



1. M. simplex, Hooh. Lond.Joum. Bot. v. 1, t. ,11 ; HooTc. Fil. 



Exot. t. 83.— Hong-kong. 



2. M. giganteum, Mettm.; Hook. 8p. Fil. 5, p. 163. — 



Tropical America. 



** Fronds pinnate, 



3. M. triphyllum, Sw. ; Soolc. et Ch-ev.Ic. Fil. 1. 120; Kwnze, 



Fil. t. 52. — India, Ceylon. 



4. M. palustre, Badd. Fil. Bras. t. 20 ; Eooh. Gen. Fil. t. 40 ; 



Lowe's Ferns, 2, t. 45. — Brazil. 



