16 CONTRIBUTIONS PROM THE NATIONAL HERBARIUM. 



opposite and petiolate, those above subopposite, finally alternate and sessile, the 

 uppermost gradually and regularly reduced, adnate and decurrent, the apex of the 

 frond acute and coarsely serrate; characteristic middle pinna? similar to the lower- 

 most but slightly longer, about 10 cm. long, 2.5 to 3.5 cm. broad, short-petiolate, 

 oblong-lanceolate, nearly straight, at the base obtusely cuneate (usually) and lobed 

 about one-half the distance to the midrib, the lobes triangular, rounded, slightly 

 oblique, about 8 to 10 on either side, these gradually much shorter toward the apex, 

 the margins of the outer portion of the pinnae merely crenate-serrate, the apex sub- 

 entire, acute; midvein of the pinnae elevated, nearly 1 mm. broad, conspicuous, 

 yellowish, with about 13 to 15 pairs of elevated freely branching yellowish veins; 

 veinlets about 5 pairs to each of the veins of the lower and middle portions of the 

 pinna, mostly simple, only the lowermost anterior one or two once-forked ; sori strictly 

 diplazioid, dark brown, elongate, the lowermost somewhat apart and longest, some- 

 what curved, the others shorter, all nearly equidistant (as to the length of the veins) or 

 nearer the costa; indusia inconspicuous. 



Type in the U. S. National Herbarium, no. 826200, collected in the forest between 

 Purulha and Panzal, Baja Verapaz, Guatemala, altitude 1,500 meters, by* Baron 

 H. von Turekheim, no. 1 1. 1683, in April, 1907. No other specimens have been seen. 

 Diplazium prominulum is related to D. subsilvaticum Christ, D. arboreum (Willd.) 

 Presl.o D. aemulum Underw. & Maxon, and D. werckleanum Christ. It resembles 

 rather closely the true D. arboreum, from which it differs in its ovate (not triangular- 

 ovate), coriaceous (not membranous) fronds, its simply acute (not elongate or caudate) 

 less deeply lobed pinnae, and its stout yellowish flexuose rachis and prominent veins. 

 Diplazium ? ternatum Liebm. 



II. 1682. Forest above Panzal, Baja Verapaz, altitude 1,400 meters, April, 1907. 

 This is perhaps the most interesting fern of the collection. The lype specimens are 

 from Oaxaca, Mexico, and the species has been reported hitherto only from Mexico. 

 The present specimens are truly ternate, but are very much larger and more deeply 

 incised than those described by Liebmann and redescribed and figured by Hooker. b 



The species was described by Liebmann as a doubtful Diplazium and was placed by 

 Hooker in his section Anisogonium of Asplenium. The venation is unique in that 

 the lowermost superior branch (from many of the lowermost veins) being once forked 

 the forks unite subsequently to form an elliptical areole, this wholly or partially fer- 

 tile, the resulting vein fertile only near the areole, parallel to the other branches, and 

 excurrent to the margin. The lateral branches are frequently soriferous in the middle 

 of the pinna.', the sori extending sometimes nearly to the margin. This is shown in 

 Hooker's figure. 



Hooker describes the sori as asplenioid along the veins that form the areole, but 

 diplazioid along the vein resulting from their union. Liebmann refers to them as 

 "simple or bilateral." The Guatemalan specimens are only sparingly fertile and 

 show hardly any truly diplazioid sori; the areoles are from 11 to 17 mm. long and are 

 produced equally in sterile and fertile fronds. 



a Diplazium arboreum (Willd.) Presl, Tent. Pterid. 114. 1836. 



Asplenium arboreum Willd. Sp. PI. 5: 320. 1810, not of recent authors. 

 Asplenium she pherdii Spreng. Nov. Act. 10:231. pi. 17. f. 5. 6. 1821. 

 Diplazium shepherdii Link, Hort. Berol. 2:70. 1833. 

 An examination of Willdenow's type specimen of Asplenium arboreum by Professor 

 Underwood and a tracing of the same seen by the writer constitute the basis for join- 

 ing the A. arboreum of Willdenow and A. shepherdii Spreng. Most of the specimens 

 passing as A. arboreum are to be referred to Diplazium semihastatum (Kunze) C. Chr., 

 a common West Indian species. 

 *> Second Cent. Ferns pi. 51. 1861. 



