﻿A NEW SPECIES OF FERN OF GENUS POLYPODIUM 

 FROM JAMAICA 



By WILLIAM R. MAXON 



Among the ferns collected in Jamaica by the writer in 1904 is a 

 simple-leaved Poly podium which is distinct from the several related 

 species of middle America. It may be known as 



POLYPODIUM NESIOTICUM new species 

 Rhizome suberect, about 1 cm. long, densely clothed with closely 

 appressed imbricate lanceolate dull light-brown scales : fronds few. 

 approximate, 15 to 22 cm. long; stipe relatively very short (1 to 2 

 cm. long), densely beset with slender spreading rigid reddish hairs; 

 lamina (largest) 20.5 cm. long. 0.9 cm. broad, bright green, firm, 

 moderately thick, linear-lingulate, rather blunt at the apex, atten- 

 uate and decurrent at the base, the under surface sparsely hairy, the 

 upper surface glabrate, the margins regularly marked by broad 

 shallow undulations, ciliate ; midvein apparent on the under surface 

 nearly throughout, on the upper surface concealed by the paren- 

 chyma except towards the base ; venation free, the oblique veins for 

 the most part alternately 3 to 5 times forked ; sori round, either 

 terminal or dorsal, wholly superficial, 2 to 4 to each group of veins, 

 irregularly disposed in two or four interrupted rows. 



Jamaica.- — Founded upon a single specimen, U. S. National Her- 

 barium, no. 520770, from the vicinity of Vinegar Hill, altitude 1200 

 meters; William R. Maxon, no. 2773; June 23, 1904. Growing 

 upon the trunk of a forest tree, ten feet from the ground. 



The present species appears to be a very rare member of a group 

 of tropical American species represented in Jamaica by the well 

 known Polypodium trifurcatum L., P. fawcettii Baker, 1 and P. den- 

 dricolum Jenman, 2 the last apparently very close to the Colombian 

 P. parietinum Klotzsch. 3 P. fawcettii and P. dendricolum have 

 been well distinguished by Jenman 4 since their original publication. 



1 Joum. Bot. Brit, and For. 27: 270. 1889. 



2 Card. Chron. in. 16 : 467. 1894. 



3 Linncea 20: 373. ^\7- Illustrated by Kunze, Farrenkr. 2: 41. pi. 117, f. I. 

 1 848-1 85 1. 



4 Bull. Bot. Dept. Jamaica 11. 4: 68-69. 1897. 



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