566 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
of the under surface are described briefly in the key. The rachis is strongly 
elevated beneath and is black or blackish, not (as in P. subvestitum and P. 
fallacissimum) more or less completely immersed in the pagina and evident 
only as a low ridge. 
Aside from the very pronounced paleaceous under surface the most conspicu- 
ous gross character lies in the slender, long-attenuate apex of the fronds, the 
terminal segment being greatly elongate, 4 to 6 times as long as the next lowest 
segments. This alone will distinguish this species from its two nearest allies, 
though its dense scaly covering beneath, the raised blackish rachis, and the 
relatively slender rhizome scales are hardly less characteristic. 
The following specimens are in the U. 8S. National Herbarium: 
Peru: Two fronds of the type collection, Steere. Andes, Wilkes Exped. 
(as Goniophlebium tweedianum), Mountains back of Lima, along the 
Oroya Railway, Safford 998. 
8. Polypodium subvestitum Maxon, sp. nov. 
Rhizomes rather short-creeping, 2 to 4 (rarely 10) cm. long, branched, 2 to 3 
mm. in diameter, freely radicose, conspicuously paleaceous, the scales appressed, 
closely imbricate, 2.5 to 3 mm. long, broadly deltoid-ovate, thin, attached above 
their rounded base, brownish in mass, thin, translucent, with a poorly defined, 
median, A-shaped zone of slightly darker cells (these with dark brown sclerotic 
partition walls and large lumina), the margins composed of pale thin-walled 
cells, the outermost row of these transversely linear, forming an irregularly 
denticulate border, the teeth mostly bipapillate at their tip. Fronds erect, sub- 
fasciculate, 8 to 16 em. long, the stipe usually much longer than the lamina; 
stipes 3.5 to 10 cm. long, about 1 mm. thick, stramineous, faintly marginate to- 
ward the apex, deeply bisuleate on the anterior face, deciduously paleaceous; 
lamina deltoid-oblong, 3.5 to 7 em. long, 2 to 4 cm. broad at the base, pinnately 
parted, with 5 to 7 pairs of oblique linear-oblong acutish dilatate segments, 
these unequal, the basal ones subdistant, 1 to 2.8 em. long, sometimes with an 
oblique lobe (2 to 6 mm. long) upon the proximal side, the middle ones closer 
and slightly shorter, the apical ones gradually much shorter and finally evi- 
dent as triangular lobes below the acute or abruptly short-caudate apex; mar- 
gins subentire to distantly repand-serrulate or, in the largest segments, coarsely 
crenate; rachis and midveins partially concealed, their course evident; veins 
free, wholly concealed, 6 to 8 pairs, spreading, subdistant, mostly twice forked, 
the branches short; sori 5 to 8 pairs, large, nearly equidistant, terminal upon 
the first branch of the veins. Leaf tissue herbaceo-coriaceous, yellowish green, 
glabrous above, partially covered with scales beneath, these subpersistent, 1.5 
to 2 mm. long, orbicular-ovate to deltoid-ovate, acuminate, light brown in mass, 
appressed, subimbricate, the cells mostly short and subhexagonal (the partition 
walls somewhat sclerotic but pale), the outermost row transversely elongate, 
forming an irregular denticulate border, the teeth bipapillate at their ex- 
tremity. 
Type in the U. S. National Herbarium, no. 833209, collected in the vicinity of 
La Paz, Bolivia, altitude about 3,000 meters, in 1889, by Miguel Bang (no. 122) ; 
distributed as. Polypodium macrocarpum Presl. 
The following additional specimens are in the U. 8S. National Herbarium: 
Borivia: A second sheet of the type collection, Bang 122. Near La Paz, 
alt. 3,000 meters, April, 1885, Rusby 865 (2 sheets). Without precise 
locality, Bang 2598 (2 sheets). 
This species is closely related only to P. fallacissimum, from which it may 
be separated by the characters mentioned in the key and under the description 
of that species, next following. 
