VOL. XVIII, PP. 215-216 OCTOBER 17,1905 



PROCEEDINGS 



OF THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



A NEW FERN FROM PORTO RICO. 



BY WILLIAM R. MAXOX. 



By permission of the Secretary of the Smithsonian Institution. 



The name Aspidium Krugii Kuhn is cited by Krug at page 112 

 of Engler's Botanische Jahrbiicher, volume 24, 1897, under 

 Aspidium rhizophyllum, as having been given to seven numbers 

 of Porto Rican specimens collected by Sintenis and distributed 

 among various herbaria. Apparently Kuhn had thought his 

 plant distinct; and its reference to the well-known Jamaican 

 A. rhizophyllum was probably due to the fact that certain of his 

 unpublished notes and manuscripts, which largely formed the 

 basis of Krug's paper on West Indian ferns, passed through 

 the hands of Dr. Christ, and that the latter's judgment was 

 followed. 



In naming a collection of Porto Rican ferns not long ago we 

 perceived the Porto Rican plant to be readily distinguishable 

 from its near ally, and we purpose to so regard it. The name 

 Aspidium Krugii having been merely listed can not be regarded 

 as published. 



Polystichum Krugii sp. nov. 



Differs from P. rhizophyllum in its thinner texture, manifest venation, 

 very much shorter stipes, longer and narrower fronds, pinnae narrower 

 and less obtuse (the upper ones greatly reduced but mostly distinct), and 

 especially in hav.ing the fructification confined to the greatly elongated 

 (10-12 cm.) linear caudate apex and the first pair or two of minute pinnae. 

 41-PROC. BIOL. Soc. WASH., VOL. XVIII, 1905. (215) 



