MAXON STUDIES OF TROPICAL AMERICAN FERNS. 41 



sistent, the margins even; receptacle capitate, somewhat hirsute, glabreecent, slightly 

 included. 



Type in the I*. S. National Herbarium, no. 523876, collected in the forest upon 

 Mount Izabel de la Torre, Santo Domingo, altitude 550 meters, Eggers 2735c. 



The species is known to the writer only from this locality, a second number being 

 Eggers 2735. It is not very closely related to any of the North American species with 

 cup-shaped indusia and is well marked by its very broad, deeply and irregularly 

 incised segments, and by its relatively few veins and large distant sori. The deltoid 

 form of the pinnules is also characteristic and very unusual in species of this group. 

 The data as to the caudex are taken from the label. 



Lycopodium underwoodianum Maxon, sp. nov. 



A very delicate, slender, freely branched pendent epiphyte, attaining a length of 

 more than CO cm., the apical portion to a distance of 10 cm. or more sporangiate with 

 little or no interruption, the sporophylls not reduced; stem very slender, 0.5 mm. 

 in diameter, many times dichotomous, flexuose, suleato, light or yellowish green 

 except toward the base, here more or less reddish; leaves light green, adnate, obscurely 

 5-ranked, divergent, all nearly equal in size, linear, strongly falciform, 9 to 12 mm. 

 long, 0.4 to 0.6 mm. broad, about 1 to 2.5 mm. apart, twisted at the base, the midvcin 

 medial, inconspicuous but visible on one surface nearly throughout, the margins 

 perfectly entire; sporophylls exactly like the leaves; sporangia conspicuous, orbicular- 

 reniform, about 1 mm. broad and long, greatly exceeding the linear sporophylls and 

 equally slender stem. 



Type in the U. S. National Herbarium, no. 575691, collected from a liane in the 

 humid forest at the finca Coliblanco, at an estimated elevation of 1,950 meters, on 

 the lower slopes of the volcano Turrialba, Costa Rica, by William R. Maxon (no. 213), 

 April 30, 1906. Specimens of the same number are also in the herbarium of the 

 New York Botanical Garden, in whose interest the collecting trip to Costa Rica was 

 undertaken. 



L, underwoodianum, though somewhat allied to L. UnifoUum and L. jenmani, is 

 one of the most distinct and strikingly peculiar species of the genus thus far discovered 

 in the American tropics. With L. UnifoUum it needs no comparison. From L. 

 jenmani u it differs wholly in its very slender stems, equal and subfiliform leaves, 

 these with an inconspicuous median midvein, and in its loose diffuse habit. It is 

 unusual for the extreme delicacy of all its parts. The stem is exceedingly slender 

 and the leaves are strongly falciform and almost capillary. The growing plant, 

 depending from a vine perhaps 15 feet from the ground, looked most like some delicate 

 long pendent moss, and the resemblance of the dried specimens to certain lax forms 

 of Sphagnum is pronounced. 



Pteris purdoniana Maxon, sp. nov. Figure 1. 



Fronds very large, 150 to 210 cm. long, simply pinnate, laxly arching, subfasciculate 

 from a relatively slight decumbent or short-creeping rhizome; stipe 25 to 45 cm. long, 

 stout, about 3.5 mm. in diameter, stramineous, villous-chaffy with numerous reduced 

 spreading or retrorse fulvous scales, tuberculate with age; lamina 125 to 165 cm. 

 long, 24 to 28 cm. broad, comprising about 60 or more pairs of linear ligulate subfalcate 

 distant pinnae and a conform terminal segment; lower pinna? very gradually reduced, 

 the lowermost 2 to 4 pairs frequently vestigial, especially in the sterile fronds; char- 

 acteristic middle pinna? of fertile frond 12 to 15 cm. long, 8 or 9 mm. broad, at the 

 base subtruncate or equally and very obtusely cuneate, falcate (especially toward the 

 apex), the apex long-attenuate and finally serrulate; pinna? of the sterile frond similar 

 in shape but broader (up to 1.7 cm. broad), usually less falcate, with cartilaginous 

 denticulate margins, the apex rather conspicuously denticulate-serrate, the base 

 equally and obtusely cuneate; pinna? uniformly articulate, inserted upon a con- 



"Bull. Torr. Oluh 33: 1 12. 1906. 



