1 12 
THE FERNS OF SOUTH AFRICA 
South Asia, Mascarenes, and Abyssinia; and collected in 
the Transvaal by Mr Bolus; at Macamac by Mr Ayres 
(Buchanan’s List, No. 4, p. 30) ; and on limestone rocks at 
the Rosehaugh lime quarry, by T. R. Sim (1914). 
Genus 8. DiDYMOCHLAENA Desvaux. 
Sori reniform or elongated, attached along its centre to 
the intramarginal raised end of a vein, which forms a linear 
elevated receptacle, and covered by a reniform or elliptical 
indusium, attached along its length to the vein, and free all 
round the edges and upper end, but emarginate at the base. 
This genus consists of only one species, distinguished from 
Polystichum and Dryopteris by its elongated receptacle and 
indusium. 
34. DiDYMOCHLAENA TRUNCATULA (Sw.) J. Sm. 
Plate 24. Nat. size. 
Stem erect, sub-arborescent, paleaceous. Frond coriaceous, 
two-pinnate, three to five feet long, one to two feet broad, with 
rachis and stipe very paleaceous, with laciniated scales half- 
inch long. Secondary rachises also scaly. Pinnae lanceolate, 
one and a half to two inches broad, with numerous, approxi- 
mate, one-sided pinnules, three-quarters to one inch long, 
three to five lines broad at the base, shortly stalked at the 
lower corner ; inner edge parallel with the rachis, entire ; 
upper edge and the rounded end toothed. Pinnules jointed 
to the rachis ; veins sub-flabeliate. Sori as described for 
the genus. A curious plant somewhat resembling some 
of the Adiantums in the form of its pinnules. 
D. truncatula (Sw.). J. Smith, Jour, of Botany , 4, 196, 1841; C. Chr. 
Index , 225. 
D. lunulata. Desv. Ann. Linn. 6, 282 ; Kze, Fit. 1, 203 ; Wood, 
Natal Ferns, 24 ; Hk. and Bkr, Syn. Fit. 248 ; Sim, Ferns of S. Afr., * 
1st ed., 164. 
D. dimidiata. Kze, Linnaea , 18, 122 ; Pappe and Rawson, 15. 
D. lu?mlata Desv., var. dimidiata. Kuhn, Fil. Afr. 157. 
Aspidium truncatulum Sw. Schrad .four. 1800 2 , 36. 1801. 
Tropical America, East Indies, Africa, and African islands. 
Natal. — Nkandhla and Ngoya forests (T. R. Sim) ; moist places in 
