50 
characters the type-specimen is scarcely to be distinguished from the form that authors 
have identified with Aspidium catocarpum Kze., which I refer to D. nemophila (Kze.) C. 
Chr. It is, therefore, an open question, whether P. amplum is the same as P. Sloanei 
Poep. or A. catocarpum Kz.; there remains the possibility that P. amplum is a species 
intermediate between the two others, but my material at hand, although rather 
comprehensive, is insufficient for solving that question. A series of perfect specimens 
from the Andes of Venezuela may show, I think, what is right. 
D. ampla is, as interpreted here, the »central« species of a number of closely 
related species, the right understanding of which is difficult, especially when one 
has to work with fragmentary specimens, which is generally the case with species 
of that size. What is called D. ampla in the literature or in herbaria is often widely 
different things; the generally large bundles of so-called D. ampla in most herbaria 
contain specimens belonging nearly to all the larger decompound species of § Ctenitis, 
and the majority of specimens quoted in papers by several authors, f. inst. GrisE- 
BACH, HOOKER, Fournier, Sopiro, Curist belong to other species; on the other 
hand Curisr has described as new species plants that are typical D. ampla. It is, therefore, 
necessary to give a detailed description of the species as I understand it. I compile 
my description partly from the original P. Sloanei, with which a complete leaf from 
Panama (Maxon no. 5786) perfectly agrees, partly from the type-specimen of 
Pe! amplum Willd. thus, noting in parenthesis the differences observed between 
P. Sloaneit and P. amplum. 
Rhizome or caudex erect, 4—5 em thick (»fougére arborescent de 3 a 4 m 
de haut«, Léon on label, it is caudex + leaves, I think), thickly covered by a 
dense mass of wool-like, silky, bright-brown or yellowish-brown, intertangled scales, 
which are 4 cm or more long, scarcely 1. mm broad, very thin, entire. Base of 
stipe with a large tuft of similar scales. »Fronds 12—14 in number, arching in a 
perfect crown« (Maxon on label). Stipe up to 70 em long, 7—8 mm thick below, 
somewhat angular when dried, shallowly trisuleate above, greenish stramineous, rarely 
brownish, when fresh densely covered with pale-brown lanceolate, antrorse scales, 
which are appressed to the stipe, loosely fixed and therefore easily lost in the her- 
barium; they leave a red point on the stipe when falling. Lamina deltoid in outline, 
1 m long or more, but often much smaller, pale or yellowish green (brownish in 
type-sp.), firmly herbaceous, quadripinnate below, tripinnatifid upwards to short of 
the acuminate apex. Pinne in about 12 pairs, the basal ones subopposite, the upper 
alternate, at distances of 5—8 cm. Basal pinne the largest, 35 cm long on stalks 
produced with the basal lower pinnula, that is about opposite to the second pin- 
nate at base. Middle pinn oblong, 30 em long, 8—9 em broad, mostly straight, 
aap a little erect, shortly acuminate, on stalks about 1 cm long, bipinnatifid 
to short of the apex, sometimes bipinnate at base. Secondary pinnulz about 20-jugate, 
