MAXON—STUDIES OF TROPICAL AMERICAN FERNS. 169 
Bommeria subpaleacea Maxon, sp. nov. PuatE 6, 
Rhizome slender (about 2 mm. in diameter), creeping, closely covered with ap- 
pressed rigid lance-acicular imbricate light brown scales (about 2 mm. long) with a 
blackish median stripe; fronds subfasciculate, apparently distichous, 8 to 13 cm. long; 
stipe 6 to 11 cm. long, straight or subflexuous, usually arcuate toward the base, stout 
(about 1 mm. thick), dark brown, at first densely and closely short-pilose, soon gla- 
brescent and lustrous, toward the base bearing a few triangular-lanceolate to ovate, 
flattish, somewhat flaccid scales, these concolorous or with a narrow darker median 
stripe, minutely erose-denticulate; lamina 3 to 5.5 cm. long, 3 to 6 cm. broad, deltoid- 
cordate, subpentagonal, bipinnately parted at the base, the basal pinnules deltoid, 
inequilateral, strongly basiscopic, coarsely and obliquely pinnatifid, having the 
inferior basal lobe crenately lobed upon the proximal margin; middle (terminal) 
portion of the lamina equilateral, acute or acuminate, deeply, regularly, and obliquely 
pinnatifid, the segments (about 3 pairs) approximate, linear-oblong to oblong, simple 
and entire, or the larger ones crenate; leaf surfaces densely strigose, the midveins 
sparingly clothed below with brownish concolorous ovate flaccid scales, these flattish 
and subimbricate; venation almost wholly areolate, the costal areoles elongate, hori- 
zontal, 5 to 7 mm, long, the others very much smaller, oblique, extending in 2 or 3 
irregular rows nearly to the margin, the ultimate (marginal) veinlets obscure, mostly 
free; sporangia borne upon all of the veins excepting most of the larger costal areoles, 
forming a conspicuous very broad marginal band. 
Type in the U. S. National Herbarium, no. 841463, collected in some part of the 
Province of Puebla, Mexico, during August, 1909, by Dr. C. A. Purpus (no. 4026). 
No other specimens have been seen. 
EXPLANATION OF PLATE 6.—Type specimens of Bommeria subpaleacea. Natural size. 
The present description adds a fourth member to the small group of species recog- 
nized by Underwood ! under the name of Bommeria, a genus first proposed by Four- 
nier? in 1870. Of the species known previously, two, Bommeria pedata and B. hispida, 
are completely free-veined; while the third, B. ehrenbergiana, which is the type of 
the genus, has areolate venation similar to that of B. subpaleacea. In habit and par- 
ticularly in their silky-strigose, pedate leaves and mostly slender, creeping root- 
stocks, all four species are much alike and they are unquestionably to be associated as 
a group, whatever its relative rank. They may be distinguished readily as follows: 
KEY TO THE SPECIES. 
Venation almost wholly areolate. 
Lamina 10 to 12 cm. long and broad, scantily short-strigose 
above, long-pilose below; sporangia confined to the 
outer areoles and free marginal veinlets, forming a 
comparatively narrow marginal band........-.-.---- 1. B. ehrenbergiana. 
Lamina 3 to 6 cm. long and broad, densely strigose upon both 
surfaces; sporangia borne upon all the veins, except- 
ing only a part of the costal areoles.........---.------ 2. B. subpaleacea. 
Venation wholly free. 
Plants relatively small, the lamina usually about 5 or 6 cm. 
(casually 9 cm.) broad and long, the pinne and seg- 
ments obtuse, rounded; leaf surfaces densely strigose 
above, below tomentose with stiff hairs intermixed... 3. B. hispida. 
Plants much larger, the lamina usually 10 to 15 cm. broad and 
long, the pinne and large segments sharply acute or 
long-acuminate; leaf surfaces scantily strigose above, 
below densely pilose, the hairs unequal and spread- 
INQ... ee eee cee cee eee eee eee erence ceeees 4, B. pedata, 
1 Bull. Torrey Club 29: 633. 1902. 2 Fourn. in Baill. Dict. Bot. 1: 448. 1876. 
