Bata 
Polystichum denticulatam J. Sm. 1841; C. Chr. Ind. 580, with synonymy. 
Nephrodium denticulatum Fée 1850—52; Hook. et Bak. Syn. 287; Jenman, Bull. 
Dept. Jamaica n. s. 3: 111. 1896; W. Ind. and Guyana Ferns 225. (For 
other synonyms see below). 
Type from Jamaica, leg. Swartz (S! H.). 
The present well-known species has in recent years commonly been referred 
to Polystichum because of its indusia sometimes being subpeltate; they are, however, 
as a rule reniform, although the sinus can be very low, sometimes scarcely visible, 
and the whole structure of the plant is considerably different from all Polysticha. 
With the three next species it forms a specialized little group, marked by the much 
divided, mostly deltoid lamina with small ultimate segments. 
D. denticulaty in a wider sense is a very polymorphous species of a wide 
distribution in tropical America. Some of the forms are confined to restricted 
areas, and one would be inclined to consider such good species, but my examination 
of a very comprehensive material has shown that even those forms that are most 
remote from the Jamaican type, are connected with it and: with each other by 
numerous intermediate forms; thus the small Mexican form, Aspid. jucundum Feée, 
is on the one side, through larger forms occurring in Central America and northern 
South America, connected with the typical form, and, on the other side, closely 
resembles the Brazilian A. gracilipes Fée, which again can scarcely be distinguished 
from A. letum Sw., a form extremely different from the Jamaican type. I have, 
therefore, found it most natural to refer all these different forms to one single 
species: D. denticulata. In the following treatment I group all the forms known to 
me under three headings based on their geographical distribution, and I confine 
myself to give special names to the more distinct forms only. 
A. West-Indian. Forms. 
1. f. genuina. — Fig. 25 a. — Rhizome erect or decumbent, sometimes shortly 
creeping, stout, at the apex with a dense tuft of glossy, castaneous, lanceolate-acu- 
minate, entire, rather thick scales, which are 2—3 cm long, 1—2 mm bread. Stipe 
up to 50 cm long, below castaneous and clothed with similar scales, upwards fusco- 
stramineous, above sulcate. Lamina deltoid, 20—40 cm long and broad, glabrous or 
sometimes with some few minute, hairlike fibrils on the rachises, membranous or 
coriaceous pale green beneath, 4—5- or even 6-pinnate. Pinnz and pinnules close, 
the basal pinnz with the basiscopic side much produced. Secondary rachises often 
flexuose. Ultimate segments obovate or oblanceolate, 5—8 mm long, 3—4 mm broad, 
cuneate at the base, the margins more or less deeply lobed and the outer edge with 
1—3 .aristate or spinulose teeth. Veins pinnate in the ultimate lobes, running to the 
teeth. Sori near the tip of the veins, 2—4 to a lobe, covered by a subpersistent, 
D. K. D. Vidensk. Selsk. Skr., naturvidensk. og mathem. Afd. 8, Rekke, VI 1. 15 
