MAXON—STUDIES OF TROPICAL AMERICAN FERNS. 577 
cited by Fournier. There can be no doubt that there are represented in P. oulo- 
lepis, P. plebejum, and the plant described in this paper as P. guttatum, three 
distinct specific forms, which, so far as the writer can perceive, show no signs 
whatever of intergradation. Although the rhizome scales of all three are 
crispate and are in general structure very similar to each other, the scales of 
the lower side of the lamina offer excellent distinctive characters. Those of 
P. oulolepis are narrow and coarsely lacerate-dentate, their slender tortuous 
apices greatly elongate and nearly filiform, as mentioned in the discussion of 
P. guttatum. 
Fournier is clearly correct in regarding P. madrense as a synonym of P. oulo- 
lepis. Smith’s larger figure illustrates the species tolerably well, especially in 
habit and in its representation of the straight, narrowly linear, distant seg- 
ments, characters which may be well observed, for example, in Pringle’s 
11799; but the scales shown in the detailed figures are sketchily and inaccu- 
rately drawn, a significant and conclusive feature, however, being the deeply 
eleft margins. 
The following specimens are in the U. 8S. National Herbarium: 
Mexico: On trees and rocks of lava fields near Eslaba, Federal District, 
alt. 2,400 meters, Pringle 11799. Region of San Luis Potosi, alt. 1,800 
to 2,400 meters, Parry € Palmer 974. Near Santa Fé, Valley of 
Mexico, Bourgeau 684. Contreras, Valley of Mexico, Orcutt 3484. 
Popo Park, State of Mexico, Hitchcock. Near Cima, State of Mexico, 
Rose & Painter 7200. Near Toluea, State of Mexico, Rose & Painter 
6798. Sierra de Tepostlin, State of Morelos, Rose & Painter 7252. 
Sierra de Pachuca, State of Hidalgo, Rose, Painfer & Rose 8754; Rose 
é Painter 6717 in part. Between Pachuca and Real del Monte, State 
of Hidalgo, Rose & Painter 6658. Ixtaccihuatl, alt. 2,400 to 2,700 
meters, Purpus 329; same region, 1905, Purpus 1593. Salto de Agua, 
State of Mexico, January, 1906, Purpus 1593. Cerro Azul, near Morelia, 
Arséne. 
21. Polypodium monosorum Desv. Ges. Naturf. Freund. Berlin Mag. 5: 319. 
1811. 
Polypodium onustum Hook. Icon, Pl. 8: pl. 749. 1845. 
Polypodium macrosorum Fée, Gen. Fil. 241. 1852, not Baker, 1885. 
Polypodium sporadolepis var. y Mett. Abh. Senckenb. Ges. Frankfurt 2: 67. 
1856. 
Polypodium molestum Mett. Ann. Sci. Nat. V. 2: 254. 1864. 
TYPE LOCALITY: Peru. 
DIsTRIBUTION : Colombia to Peru, ascending to 3,400 meters. 
ILLUSTRATIONS: Hook. op. cit. pl. 749 (as P. onustum) ; Fée, Mém. Foug. 6: 
pl. 8. f. 1. (as P. macrosorum). 
In the group of species with dark-colored rhizome scales this is nearly the 
counterpart of P. lindenianum Kunze, of the group with larger, flaccid, light- 
colored thin-walled scales. It is a plant of very distinctive form and shows 
no near approach to P. murorum, which has very different scales and is at most 
only bipinnatifid. 
The substitute name molestum, proposed by Mettenius in 1864, seems to 
have been quite unnecessary, since the plant which he described as “ P. onus- 
tum Hook.” in 18561 undoubtedly does appertain to Hooker’s species of that 
name. This in turn is clearly conspecific with Fée’s P. macrosorum, which 
Mettenius” had regarded as a form (var. y)of P. sporadolepis. All are doubt- 
7Abh. Senckenb. Ges. Frankfurt 2: 68. 1856. 
"Ibid. 2: 67. 1856. 
