117 



A NEW SPECIES OF FERN OF GENUS POLY- 

 PODIUM FROM JAMAICA. 



By William R. MAXON, U. S. Nat. Museum, Washinton, D. C* 



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

 a simple-leaved Polypodium which is distinct from the several re- 

 lated species of middle America. It may be known as POLYPODIUM 

 NESIOTICUM, new species. 



Rhizome suberect, about I cm. long, densely clothed with close- 

 ly appressed imbricate lanceolate dull light-brown scales ; fronds 

 few, approximate, 15 to 22 cm. long ; stipe relatively very short 

 (I to 2 cm. long), densely beset with slender spreading rigid red- 

 dish hairs ; lamina (largest) 20 5 cm. long, 09 cm. broad, bright 

 green, firm, moderately thick, linear-lingulate, rather blunt at the 

 apex, attenuate 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 under surface con- 

 cealed by the parenchyma 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 

 Herbarium, No. 520,770 from the vicinity of Vinegar Hill, altitude 

 1200 meters ; William R. Maxon, No. 2773 ; June 23, 1904. Grow- 

 ing 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 trifiircatum. L. and by P. Faivccttii, Baker,t 

 and P. deiidricolum, Jenman+ the last apparently very close to the 

 Colombian P. /'(7r/c//«!<;«, Klotzsch.§ P. Faivccttii and P. deiidrico/iini 

 have been well distinguished by Jenman [| since their original 

 publication. P. ncsiotictim is very distinct from both, but for the 

 benefit of those who have not material of these rare species the 

 following notes may be of use. 



P. Fawcetiii is correctly said by Jenman to be " infrequent at 

 4,000 to 6,000 feet altitude in damp forests on the trunks and 

 branches of trees." Two numbers (2723, 2760) were collected in 

 such situations by the writer in 1903 and 1904. It is character- 

 ized, briefly, by its dark villous slender conspicuously upright 

 rhizome, numerous closely set small, very narrow fronds, and al- 

 most simple veins, — the sori being borne in two rows near the 

 midvein, each upon a short spur given off by the otherwise simple 



* Reprinted from SMITHSONIAN MISCELLANEOUS COLLECTIONS (QUARTEELY ISSUE) 

 Tolume 47. Published April 5, 1905. 



^Jmirti. Bot. Srit. and For. 27 ; 270. 1889. 



t Gai-A. Chron. HI. 16 ; 467. 1894. 



§ Linnaea 20 ; 373. 1847. Illustrated by Kunze, Farreukr. 2; 41. pi. 117, f. 1. 

 1848-1851. 



II Bull. Bot. Dcpl. Jamaica II 4 , 68-69. 1897. 



