MAXON—STUDIES OF TROPICAL AMERICAN FERNS. 159 
recently! the new genus Sphenomeris, with the West Indian 0. 
clavata as its type, Sphenomeris clavata. Besides the common Old 
World species Sphenomeris chinensis? and the Philippine 8S. retusa * 
there are several others to be removed hither from so-called Lindsaya 
and Schizoloma. 
From the above it will appear (1) that Kuhn was the first, and 
up to the present has been the only one, to recognize the coherence 
of the climbing indeterminate “Davallias” as a distinct generic 
group; (2) that his error was mainly one of taxonomic practice in 
applying to this the new name Lindsayopsis, whereas it should have 
retained the name Odontosoria; (3) that the small group of species 
typified by Odontosoria clavata and O. chinensis of authors is to be 
recognized as a distinct genus, Sphenomeris, allied to Odontosoria, 
Lindsaya, and Schizoloma. 
Even the commoner species of Odontosoria have been subject to 
much misidentification, which, considering their peculiar morphology, 
is not remarkable. Most of the confusion centers upon the varying 
application of the Linnzan name aculeatum in the past, as discussed 
at some length below. In lieu of complete descriptions of all the 
species the following key is made rather more full than would otherwise 
be necessary. 
ODONTOSORIA (Presl) Fée. 
Odontosoria (Presl) Fée, Gen. Fil. 325. 1852. 
Davallia § Odontosoria Presl, Tent. Pter. 129. 1836, in part. 
Relatively large plants of scandent habit, the fronds ascending, elongate, of inde- 
terminate growth, the opposite primary pinnz borne in acropetal succession. Rhi- 
zomes slender (2 to 4 mm. in diameter), woody, creeping, densely paleaceous, more 
or less freely branched. Fronds elongate-deltoid to linear, up to 6 meters long, the 
primary rachis woody, subterete to trigonous, smooth or variously spiny; lamina 
bipinnate to quadripinnate, in most species finely dissected, the ultimate pinnules 
variously lobed, cleft, or parted, the straight or usually flexuous rachises spiny or, 
in a few species, unarmed; veins forked, free; sori terminal, 1 to 3 to each ultimate 
segment, more or less endophyllous, the indusium either wholly joined to the scarcely 
different opposed leaf lobe and forming an urceolate or obconical involucre open only 
at the leaf margin, or in some species partially free at the sides, the involucre then 
slightly bilobed; spores triplanate. 
Type species, Odontosoria uncinella (Kunze) Fée. 
KEY TO THE SPECIES. 
Plants provided with stout to slender spines upon some or all 
of their rachises. 
Ultimate (terminal) divisions relatively coarse, cunei- 
form, narrowly deltoid, obovate, or rhombic from 
a sharply cuneate to inequilateral rectangular 
base, variously cleft, lobed, or incised, the lobes 
not monosorous. 
1 Journ. Washington Acad. Sci. 8: 144. 1913. 
2 Adiantum chinense L. Sp. Pl. 1099. 1753. 
3 Davallia retusa Cav. Descr. Pl. 278. 1802. 
