38 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



Hooker's plate and description indicate well the excellent characters of the present 

 species, which is confined to Jamaica. Only the following specimens have been 

 studied, these showing the relatively slight variation mentioned by Hooker: 



Jamaica: Arntully, Harris 5952. Without locality, Gilbert 38; Jenman; J'urdu; 

 N. Wilson; Hart 28. 



19. Polystichum underwoodii Maxon, sp. nov. Plate 9. 



' tAspidium triangulum latipinnum J enman, Journ. Rot. 17: 260. 1879; ?Bull. Bot. 

 Dept. Jamaica II. 2: 2G9. 1895; not Aspidium latipinna llance, 1873. 



Fronds 40 to 50 cm. long, fasciculate, suberect or spreading, long-stipitato, tolerably 

 stout, simply pinnate, proliferous. Rhizome stout, 1.5 to 2.5 cm. in diameter, sub- 

 erect or decumbent, thickly clothed with imbricate lanceolate to narrowly ovale 

 scales, some of these fulvous but most dark brown or blackish and shining; stipe 15 to 

 27 cm. long, canaliculate, stramineous, covered at the base with large scales similar 

 to those of the rhizome, otherwise rather densely clothed with deciduous linear- 

 lanceolate attenuate reddish brown scales; lamina very narrowly deltoid, 20 to 25 

 cm. long, 5 to 7 cm. broad, at the base, once pinnate, tapering very gradually to the 

 pinnatifid or subentire elongate deeply retuse proliferous apex; pinnae 15 to 20 pairs, 

 glabrous and dark green above, below lighter colored and minutely paleaceous-pilose, 

 divergent, the lower ones their own width apart, subpetiolate, those above somewhat 

 less spaced, sessile, the upper ones greatly reduced, adnate and joined by a narrow 

 wing; lowermost pinnae 2.5 to 3.5 cm. long, 13 to 15 mm. broad, rhombic-ovate, the 

 apex mucronate, the base unequally and rather obtusely cuneate; margins subentire 

 or, less often, coarsely crenate, the crenations not spinescent; sori nearly media!, 

 borne in two rows of about 8 each and an incomplete row at the superior base; indusia 

 large, brownish, subpersistent. 



Type in the U. S. National Herbarium, no. 521270, collected near the summit of 

 Blue Mountain Peak, Jamaica, altitude 2,100 to 2,225 meters, by Lucien M. Under- 

 wood, no. 1441, February, 1905. Specimens collected by the writer at the same 

 locality under no. 1428 represent the crenate form included in the description. These 

 last are, in part, subauriculate, the basal crenation in a few cases extending nearly 

 half way to the midvein of the pinna. Harris 7516, from Mount Hybla, altitude 

 1,200 meters, represents a smaller and less complete development of the species. 



For his variety latipinnum Jenman cites only specimens from Arntully Gap, alti- 

 tude 600 meters. His incomplete description accords well with the present diagnosis, 

 but relatively few Jamaican ferns show so great an altitudinal range. Jenman's 

 specimen of his variety latipinnum at the New York Rotanical Garden is without 

 definite locality data; it differs somewhat in its more regular and very broad pinme 

 and is not truly typical of the species as here defined on the basis of the Riue Moun- 

 tain Peak plants. 



Polystichum underwoodii is distinguished readily from all the other pinnate vivip- 

 arous species by its nonflageliiform and deeply retuse apex. 



Explanation of Plate 9.— The type specimens. Scale about 3. 

 SPECIES EXCLUDENDAE. 



Aspidium cubense Kuhn, Linnaea 36: 108. 1869. 



Founded upon Wright 1099 from Cuba; transferred to Nephrodium by Raker (1874) 

 and to Dryopteris by Kuntze (1891). From its indusia it is properly a Dryopteris, 

 and is related to D. denticulata, which Diels follows John Smith in considering a 

 Polystichum. 



Aspidium jucundum Fee, as noted at page 18 of this paper, is probably an earlier 

 name for 1). cubensis. 



