598 



THE GARDENER'S ASSISTANT. 



brown. Var. flexuosa. — Fronds 3 to 

 flexuose, subscandent. Mexico. G. 



P. falcata. — Fronds 1 to 2 feet long, pinnate; pinnae 

 narrow-lanceolate, falcate, dark-green; stipes and rachis 

 scaly. Australia. G. 



P. rotundifolia. — Fronds 12 to 18 inches long, pinnate, 

 linear; pinnae subrotund, crenate, deep-green; sori form- 

 ing a brown band round the pinnae; stipes and rachis 

 clothed with reddish-brown scales. New Zealand. G. 



Phlebodium. See Polypodium. 



Platycekium. — Distinct epiphytal Ferns with dimor- 



phous fronds, the sterile being imbricating and sessile, 

 whilst the fertile are forked or lobed, antler-like, the sori 

 occupying large unequal patches on the under side of the 

 lobes. These plants thrive in baskets of rough peat and 

 sphagnum; they also form beautiful objects if fastened 

 to a bracket of wood or cork and grown in the stove. 



P. cethiopicum (Stemmaria). — Sterile fronds almost 

 entire, 1 to 2 feet in diameter; fertile simple, two- to 

 three-lobed, widening upwards, 1 to 2 feet long. West 

 Africa. 



P. alcicorne, Elk's-horn Fern (fig. 726). — Sterile fronds 



Fig. 7^t>. — Platycerium alcicorne. 



imbricating, nearly round, upper edge lobed ; fertile 

 stipitate, erect, several times forked, leathery. Australia. 

 G. 



P. biformc. — The largest of all, sterile fronds imbri- 

 cating, forked on the upper edge; fertile ones elongated, 

 several times branched; segments long, strap-shaped, the 

 fertile lobes reniform, stalked. Borneo. 



P. grande. — Sterile fronds broad and imbricating, 1 to 

 2 feet in diameter, lobed; fertile branched, 1 to 3 feet long, 

 the sorus occupying the upper edge of the disc. Tropical 

 Asia. 



P. WillincJcu (fig. 727). — Sterile fronds erect, deeply 

 lobed, 12 to 18 inches wide; fertile ones in threes, pen- 

 dent, 2^ feet long, divided into narrow segments, bearing 

 spores near the tips. Java. 



Polybotrya. See Acrostichum. 



Polypodium. — A large and polymorphic genus, now 

 embracing Phegopteris, Goniopteris, Dictyopteris, Gonio- 

 phlcbium, Niphobolus, Phymatodcs, Pleopeltis, and Dry- 

 naria. Characterized by round or nearly round sori 

 without indusium. The species vary considerably in 

 venation. 



P. aureum. — Fronds pinnatifid, 2 to 6 feet long ; 



segments obtuse, wavy, bluish - green ; sori forming a 

 double row on each side the costa; rhizome clothed with 

 large ferruginous scales. Var. areolatum has fronds 1 to 

 2 feet long, the sori forming a single row on each side the 

 costa. Tropical America. Var. sporodocarpum has broad 

 fronds, with deeply - pinnatifid long narrow segments. 

 Var. pulvinatum has numerous golden-yellow sori. 



P. {Drynaria) conjugatum (coronans). — A noble species; 

 fronds pinnatifid, erect, 2 to 4 feet long, 1 to 2 feet wide, 

 with a dilated base, pale-green. East Indies. 



P. crenatum. — Fronds pinnate, 10 to 18 inches long; 

 pinnae 4 to 6 inches long, 1 to 2 inches broad, evenly 

 crenulate, bright-green. West Indies. 



P. {Drynaria) diver si folium. — Sterile fronds sessile, 

 cordate at the base, deeply lobed on the upper edge; 

 fertile fronds elegantly pinnate, pendulous, 2 to 4 feet 

 long, pale-green. Malay Archipelago, &c. 



P. Lepidopteris. — Fronds pinnate, lanceolate, 12 to 18 

 inches long; pinnae sessile, dark-green, clothed with white 

 ciliated hairs ; sori deep-red. Tropical America. 



P. lingua. — Fronds entire, lanceolate accuminate, 6 to 

 12 inches long; dark -green with white scales, the under 

 side densely pubescent; sori red, covering the whole 



