151 GREENHOUSE FERNS. 



Fronds pinnated, growing a foot or more long, and reclining. 

 We never saw them, however strongly grown, stand upright. 

 Pinnae nearly round, stout, and dark green, and slightly 

 hollowed-out at the edges. Stalks covered with brown scales. 

 Increased readily by dividing the creeping rootstock. This is 

 also a most desirable Fern, and thrives well in a Wardian case. 

 It is also very suitable for cultivation in a basket. 



POLYPODUJM. 



Under this name there were formerly arranged a great 

 number of species of very various forms and habit of growth 

 in fact it was an incongruous assemblage ; but they have now 

 been divided into many distinct genera, so that under the old 

 name there are but comparatively few species left. 



POLYPODIUM PLEBEJUM (Homely or Simple). A native of 

 Mexico, and a very interesting little Fern. It is somewhat 

 rare yet, but well deserves a place in every greenhouse col- 

 lection of Ferns. The fronds are not more than 4 inches in 

 length, dark green, and sprinkled with brown scales, which 

 make very interesting objects under the microscope. 



P. SUBPETIOLATUM (Short- stalked). A Mexican Fern of 

 considerable beauty. Fronds pinnate, growing, with ordinary 

 care, 2 feet high, narrow, lance- shaped, covered with very fine 

 short hairs ; pinnae quite smooth, with very short footstalks. 

 Easily increased by dividing the scaly creeping rhizome. 

 Even this species is sometimes put into the genus Goniophle- 

 bium, and, strictly speaking, perhaps P. plebejum is the only 

 true greenhouse Polypody. 



POLYSTICHUM. 



This name is derived from the Greek polys, numerous, and 

 stichos, order ; the spore-masses being in many regular lines. 

 This genus is nearly related to Lastrea, but may easily be 



