148 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
14. Asplenium carolinum Maxon, sp. nov. 
Rhizome erect or ascending, woody, about 5 mm. in diameter, somewhat sheathed 
by the persistent stipe bases of old fronds, the crown obscurely paleaceous, the scales 
rigid, linear-lanceolate, 1.5 to 2.5 mm. long, yellowish brown with a distinct dark 
brown median stripe; fronds 8 to 12, 10 to 20 cm. long, ascending, borne in a close vasi- 
form crown; stipes short, stoutish (1 mm. thick or less), subterete, the anterior face nar- 
rowly sulcate, the ridges noticeably alate; lamina narrowly linear-oblanceolate, 8 to 
18 cm. long, 1.2 to 2 cm. broad, pinnate, rather abruptly acute at the apex, the lower 
portion more gradually reduced; pinne numerous, spreading, distant to adjacent, the 
lower ones deltoid, deeply parted, the lowermost minute; middle pinne 7 to 10 mm. 
long, 3 to 4 mm. broad, oblong froma broadly cuneate or subrectangular base, subauricu- 
late by the incision of the upper margin near the base, the auricle or lobe distinctly 
2 to 4 dentate, the upper margin elsewhere more or less deeply crenate-serrate or 
obliquely incised (the crenations simple or faintly bidentate), the lower margin 
entire in the proximal half, obliquely crenate toward the apex; veins 4 to 6 pairs, 
very oblique, the superior basal one 1 to 3 times forked, the others simple or (in the 
case of the larger bidentate crenations) forked at a very acute angle, all nearly con- 
cealed; sori 2 or 3 pairs, borne in the outer half or two-thirds of the pinna, elliptical, 
tumid, very oblique; indusia firm, ample, subentire. Leaf tissue firmly chartaceo- 
coriaceous, dull dark green, the lower suriace minutely puberulent. 
Type in the U. S. National Herbarium, no. 25611, collected upon Charles Island, 
one of the Galapagos group, by Leslie A. Lee, April 8, 1888, during the voyage of the 
U.S. Bureau of Fisheries Steamer Albatross (1887-1888). 
Specimens which presumably are of this species have hitherto been reported from 
the Galapagos Islands as Asplenium formosum, of which A. carolinum is a close ally. 
This species differs from A. formosum principally in its obtuse and less deeply incised 
pinne, in having the crenations of the pinne simple or faintly dentate (instead of 
deeply and sharply cleft), and in its shorter and less oblique sori which are arranged 
in pairs, instead of in a single series upon the proximal side of the pinne. In all 
probability Asplenium carolinum is a derivative of A. formosum and the differences 
noted are doubtless to be associated with its isolation far from the mainland. 
15. Asplenium platyneuron (L.) Oakes; D. C. Eaton, Ferns N. Amer. 1: 24. 1878, 
Acrostichum platyneuros L. Sp. Pl. 1069. 1753, in part. 
Asplenium ebenewm Ait. Hort. Kew. 8: 462, 1789. 
Asplenium trichomanoides Michx. Fl. Bor. Amer. 2: 265. 1803. 
Asplenium polypodioides Swartz, Journ. Bot. Schrad. 18002: 53. 1801. 
TYPE LOCALITY: Virginia. 
DisTRIBUTION: Maine and southern Ontario to Florida, westward to Texas and 
Colorado. Also in South Africa. 
Intustrations: Schkuhr, Krypt. Gewichs. 1: pl. 73 (as Asplenium polypodiotdes); 
D. C. Eaton, loc. cit. 1: pl. 4. f. 1 (as Asplenium ebeneum); Williamson, Ferns 
Kentucky pl. 17. . 
Among the species of this group Asplenium platyneuron is unique in having the 
fertile and sterile fronds very unlike each other in both form and stature. The rela- 
tively short sterile fronds (which are evergreen) form a basal rosette, radiating from 
the rhizome and lying close to the ground. The fertile fronds are tall and fewer in 
number and are borne stiffly erect from the center of the rosette, There is a good deal 
of variation in the degree of serration of the pinne, and several varietal forms have 
been described, one of the most pronounced being the variety hortonae, of New Eng- 
land. This has the pinnz deeply pinnatifid, and in its extreme form issterile. Plants 
with pinne irregularly and often deeply incised are not at all uncommon, especially 
in the southern United States, but these are only extremes of a tendency which may 
be noted in any region where this species is abundant, and numerous specimens occur 
which are intermediate in every respect. 
