DESCRIPTIONS OF THE SPECIES 
125 
the spreading side veins each forked into three or four sub- 
parallel veinlets, the upper one of which is rather shorter than 
the others, and ends in an intramarginal round sorus, covered 
by a roundish or emarginate indusium, opening outward. This 
is a very natural little tropical genus containing 17 species, of 
which one species extends to Natal, and two others occur in 
Zambesia. In cultivation many have developed crested or 
abnormal forms more or less permanent. 
45. Nephrolepis biserrata (Sw.) Schott. 
Plate 35. Nat. size. 
Crown tufted. Frond pinnate, sub-coriaceous, widely 
lanceolate, three to four feet long, eight to twelve inches 
broad, with a short stout stipe, which is slightly scaly at 
the base. Pinnae sessile, alternate, glabrous, articulated 
to the rachis, lanceolate-acuminate from a rounded base, 
four to six inches long, three-quarter inch broad; the lower 
barren ones finely serrate ; the fertile with shallow crenations 
two lines wide, which are slightly serrated, or with a small 
tooth between each. Sori in a straight line, one below each 
sinus, and about a line distant from it. Indusium reniform 
or nearly round, persistent. Rachis almost glabrous, or with 
rufous shag about the base of the pinnae. 
Nephrolepis biserrata Schott. Kuhn, Fil. Apr. 155; Sim, Ferns of 
S. Africa , 1st ed., 188 ; C. Chr. Index , 453. 
Nephrolepis acuta Presl. Hk. and Bkr. Syn. Fil. 301. 
Aspidium biserratum Sw. Schrad. Jour. 1800 2 , 32, 1801. 
Tropics generally, including in Africa: — Natal, Angola, 
Guinea Coast, Zambesiland and Mascarene Isles. 
Natal. — (Gueinzius) ; abundant in openings in the bush swamp at 
head of Bay of Natal, and a few plants on rocks by Palmiet and 
Nonoti only (Buchanan, Wood). 
46. Nephrolepis exalt at a (Linn.) Schott. 
Plate 61. Fig. 1. Nat. size. B Vein and sorus, x 4. 
Crown erect, stout, with numerous long wiry runners from 
which new plants arise ; frond two to four feet long, three to 
