MAXON — STUDIES OF TROPICAL AMERICAN FERNS. 43 



Polypodium mitchellae Baker in Hemsl. Biol. Centr. Airier. 3: 664. 1885. 



The original specimens of this species are from Orange Walk, British Honduras, 

 Mrs. Mitchell. It has also been collected at Chontales, Nicaragua, by Tate (no. 406). 

 Specimens of both these collections are at Kew and in the herbarium of the New 

 York Botanical Garden. 



The species may now be recorded also from the humid mountainous region of 

 eastern Guatemala, on specimens collected from the trunks of forest trees near Secan- 

 qufm, Alta Verapaz, at an altitude of about 450 meters, Maxon & Hay 3195 and 3213. 

 It may bo expected also in eastern Costa Rica, at low or middle elevations. 



Polypodium senile Fee, 7me Mem. 60. pi. 25. f. 1. 1857. 



A species apparently little understood, founded on Schlim's no. 364, from the prov- 

 ince of Ocana, New Granada. It is accredited to Colombia and Ecuador by Christen- 

 sen, following Hieronymus;" and it appears also to extend as far north as the vol- 

 canoes of Costa Rica, on the basis of specimens which the writer for several yeare took 

 to represent an undescribed species. Comparison of this northern material, however, 

 with Colombian specimens shows no differences warranting separation. From the 

 whole' variable series, but mainly from the more complete Costa Rican material, the 

 following description is drawn: 



Plants pendent, the fronds lax, subflexuose, narrow, from a very slight rhizome, 

 this bearing a few setose fulvous scales intermingled with long whitish hairs; stipe 

 and rachis exceedingly delicate, wiry, flexuose, covered with long whitish or pale yel- 

 lowish hairs, these radiating also in great profusion from the sori and less abundantly 

 from the tissue of the under surface of the pinnae; lamina slender and narrow, 15 to 25 

 cm. long, 8 to 15 mm. wide, comprising from 30 to 50 pairs of pinna 1 , these distant or 

 their own width apart (rarely approximate); larger pinnae of mature fronds 7 to 9 mm. 

 long, 2.5 to 3.5 mm. broad, narrowly oblong or infrequently subovate with a rounded 

 basal auricle, narrowed at the base, partially adnate or rarely subsessile, the extent 

 of adnation commonly about one-half the maximum width of the pinna, the margins 

 entire or slightly sinuate; lower pinme gradually smaller, the lowermost 4 or 5 pairs 

 vestigial, minute, 6 to 8 mm. apart; sori of characteristic pinnie about 6 pairs, con- 

 tiguous, strongly confluent with age, borne nearer to the midvein than to the margin 

 at the extremity of the short subopposite simple blackish veinlets. 

 The following specimens have been examined: 

 Colombia: Sierra del Libano, Santa Marta, altitude 1,650 meters, damp forest 

 on a ridge, pendent from branches of trees, 77. II. Smith 2230 (Y). Cerro 

 de Onaca, Santa Marta, altitude 1,650 meters, on a tree, 77. IT. Smith 2437 

 (Y). Sierradel Libano, Santa Marta, altitude about 1,800 meters, damp forest, 

 on trees, hanging from the branches and often hidden among mosses and Ily- 

 menophyllaceae, //. II. Smith 1035(Y). Without special locality, Lindig(Y). 

 Costa Rica: Volcan de Turrialba, altitude 2,600 to 2,800 meters, Pittier 13248 

 (J. D.S. 7497) (N). Forets de l'Achiote, Volcan de Poas, altitude 2,200 

 meters, Tonduz 10706 (N). Forets du Volcan du Barba, altitude 2,500 

 meters, Tonduz 1934 (N). Massif de l'lrazu, altitude about 2,000 meters, 

 Tonduz 4180 (N). Without locality, Werckk, ex herb. Christ (N). 

 The Costa Rican specimens show a tendency to have the pinme more spaced and 

 less adnate to the rachis than those from Colombia, the best development being rep- 

 resented by Mr. Pittier's no. 13248. Mr. II. II. Smith's no. 1035 is the most mature 

 state of the Colombian specimens. 



From P. cultratum the present species is readily distinguished by (1) its dark vena- 

 tion, the branches of the midvein being blackish (green in P. cultratum), (2) its 

 spaced, less adnate, even subsessile pinna-, these not recurved, (3) its more copious 

 hairy covering, this much lighter in color, and (4) its more slender vascular parts. 



a See Hieronymus in Engler's Bot. Jahrb. 34: 508. 1905. 

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