12 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



produced apex; characteristic middle pinnae 7 to 9 mm. long, about 1.5 mm. broad, 

 spaced their own width, forming an acute angle of about 45° with the rachis, straight, 

 linear-oblong with entire slightly reflexed margins, at the apex obtuse (sometimes 

 subacute in drying), at the base fully adnate, slightly dilatate both above and below, 

 with obtuse sinuses, the rachis not alate; midvein dark, evident below, nearly straight, 

 with about 6 pairs of acute simple greenish mostly soriferous veins, the clavate apices 

 reaching the upper surface and there evident as reddish brown medial dote; sori 

 superficial, about 6 pairs, distinct, small, slightly nearer the midvein than the margin, 

 near the end of the veins; sporangia glabrous; paraphyses or intermixed hairs none. 



Type in the U. S. National Herbarium, no. 579,030, collected from tree trunks in 

 the forest near Coban, Alta Verapaz, Guatemala, at an altitude of 1,350 meters, by 

 Baron II. von Turekheim (no. II. 1347, in part), November, 1907. Mixed with this 

 are specimens of what appears to be a form of Polypodium rigens Maxon, a species 

 reported hitherto only from Jamaica. This is distinguished readily by its stouter" 

 rhizome, its more conspicuous, larger, more abundant and straighter chaff, its stouter 

 stipes, these covered with long stiff reddish hairs, ils broader and relatively shorter 

 lamina?, usually long-caudate at the apex, and its opaque, broader, and more rounded 

 pinna', these borne nearly at right angles to the rachis and reduced more abruptly 

 at the base of the lamina. 



Polypodium productum is known also from Baron von Turekheim 's no. 53, in part, 

 distributed by Captain Smith, from the same locality. Mixed with it, however, are 

 plants of P. rigens, mentioned above, and of another species even less closely allied 

 to P. productum, and apparently undescribed. 



In relationship P. productum stands somewhat apart. It is not, strictly, a member 

 of the pilosissimum group, /'. pilosissimum itself being a species little collected and 

 and not well understood. In size and general appearance P. productum bears a close 

 resemblance to a species of an entirely different group, namely J', jubiforme Kaulf., 

 from which it differs in its superficial sori, in its spaced, scarcely decurrent, and 

 more 'fertile pinnte (the sori not confined to the outer portion), and in numerous 

 more technical characters. 



Polypodium rigens Maxon. 



II. 1347, in part. Coban, altitude 1,350 meters, November, ]<;<)7. Epiphytic, 

 Described originally from Jamaica and not hitherto reported from Central America. 



Polypodium suspensum L. 



II. 2270. Coban, altitude 1,600 meters, May, 1908. 



Polypodium trichomanoides L. 



II. 2383. Coban, altitude 1,350 meters, May, 1908. 



Xiphopteris serrulata (Sw.) Kaulf. 

 II. 1261. Coban, altitude 1,350 meters, November, 1907. Epiphytic. 



Tribe PTKRIDEAE. ' 

 Adiantum capillus-veneris L. 



II. 1681. Panzal, Baja Yerapaz, altitude 1,000 meters, April, 1907. On rocks in 



small streams. 

 II. 2074. Under a waterfall between Tactic and Coban, Alta Verapaz, altitude 

 1,600 meters, December, 1907. 



Adiantum concinnum H. & B. 

 II. 2075. Near Ran Cristobal, Alta Verapaz, altitude 1,400 meters, in moist, shady 

 situations, December, 1907. 



Adiantum dolosum Kunze. 



II. 50. Cubilquitz, altitude 350 meters, July, 1907. 



