10 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



Polypodium christensenii Maxon, pp. nov. 



Fronds largo, 1 to 1.2 meters long, densely glandular-pubescent throughout, borne 

 singly, 2.5 cm. apart; rhizome firm, creeping, 8 mm. in diameter, very thickly 

 covered with spreading ferruginous scales, these most numerous at the base of the 

 stipe, 9 to 14 mm. long, narrowly ovate to ovate, long-acuminate, attached near 

 their base, the margins subentire, involute in the long-attenuate apical portion; 

 stipe about 33 cm. long, stout, 3 to 4 mm. in diameter, dark brown, densely glandular- 

 pubescent, the upper face deeply sulcate; lamina herbaceous, about 85 cm. long, 

 35 to 40 cm. broad at or just, above the base, lanceolate-deltoid, once pinnate through- 

 out, the pinnae (about 35 pairs) whitish glandular-pubescent upon both surfaces, 

 more conspicuously so upon the upper; basal pair of pinnee deflexed, distant, 17 to 

 19 cm, long, 17 mm. broad in the middle, slightly narrowed toward the adnate base, 

 tapering gradually in the outer part to a subacute apex, the margins irregularly crenu- 

 late-serrulate; succeeding pinna; similar, at least their width apart, subopposite, 

 horizontal, fully adnate, slightly longer than the basal or not, those of the upper 

 two-thirds of the lamina very gradually shorter and a little closer, slightly dilatate, 

 but neither surcurront nor decurrent, the sinuses wide and obtuse, the apex of the 

 lamina deeply pinnatifid almost to the end; rachis and costse densely glandular- 

 pubescent, the latter elevated below; veins free, 45 to 48 pairs, dark-colored, 4 or 

 mostly 5-forked, the branches divergent, glandular-pubescent like the costa, the 

 leaf tissue also minutely glandular-pubescent below; sori superficial, 40 to 45 pairs, 

 large, borne mostly upon the first anterior branches, casually also upon the first 

 posterior and second anterior branches, thus imperfectly uniserial, inframedial. 



Type in the U. S. National Herbarium, no. 591558, collected in the mountains 

 near Coban, Alta Verapaz, Guatemala, at an elevation of 1,600 meters, by Baron 

 11. von Tiirckheim, no. II. 2179, in March, 1908. Specimens long ago distributed 

 by Captain Smith under no. 3263c, from San Miguel U span tan, Quiche, Guatemala, 

 altitude 1,800 meters, are the same. 



Related to P. biauritum, above described, from which if differs not a little in its 

 differently shaped lamina and pinnee, its more freely branched veins, its more 

 general pubescence, its different margins, and its attenuate, spreading chaff. In 

 general appearance and marked pilosity it suggests rather P. macrodon Hook. (/'. 

 legionarium Baker) of the same region, a species invariably with sessile, deeply and 

 regularly incised pinna; and a long conform terminal segment. /'. christensenii is 

 one of the most distinct and probably the largest species of the subgenus Eupoly- 

 podium, as commonly understood; it is named in honor of Mr. Carl Christensen, of 

 Copenhagen, in grateful appreciation of numerous courtesies extended to the writer. 

 Polypodium cultratum Willd. 



II. 2034. Between Tactic and Cohan, Alia Verapaz, altitude 1,800 meters, Decem- 

 ber, 1907. Epiphytic. 

 Polypodium fallax Cham. & Schlecht. 



II. 85. Cubilquitz, altitude 350 meters, July, 1907. Epiphytic. 

 Polypodium furfuraceum Schlecht. & ('ham. 



II. 31. Cubilquitz, altitude 350 meters, July, 1907. 

 Polypodium leucosticton Kunze. 



11. 1397. Coban, altitude 1,350 meters, October, 1907. 



The synonymy and range of variation of this species has recently been given at 

 some length by Hieronymus.o who cites numerous South American specimens. Poly- 

 podium plebcium variety palmense Christ, b is the same, as shown by a specimen from 

 the type locality: La Palma, Costa Rica, altitude 1,450-1,550 meters, Maxon 449. 



So far as the writer knows, the species has not been known hitherto from Guatemala. 



«Engler's Bot. Jahrb. 34: 521, 522. 1904. 

 &Bull. Herb. Boiss. II. 5: 4. 1905. 



