DIDYMOCHL^NA. 



the description of the Russian Itotanists. Linnaeus had 'probably this plant in 

 view, when he gives his Aspl. rhizophyllum as a native of Siberia. 



SuBORD. VIII.— ASPIDIACE.E, Pr. 



' Sori dorsal, subglobose, rarely elliptical. Involucre superior, 

 orbicular and fixed by the centre (peltate), or cordate or reni- 

 form and fixed by the sinus, or elliptical and attached by a 

 longitudinal receptacle; the margins free all round or nearly 

 so. — Ferns very various in habit ; veins free or variously 

 anastomosing. 



The genera I am disposed to admit under this Order are as follows: — 1. Didy- 

 MOCHL^NA. 2. AspiDiuM, niainlv distinguished by its more or less orbicular 

 peltate involucres, with the following sectionn or subgenera -. — § Polystichum, 

 § CvcLODiuM, § CvRTOMiDM, § EuASPiDiuM, ncxt to which I am disposed to 

 place § Sagenia. 3. Nephrodium, Rich, and Br., chiefly distinguished by 

 its cordate or reniform involucre, fixed at the sinus. Subgenera. § Lastrea, 

 with free veins. § Eunephrodium, icith connivent veins, including Pleoc- 

 NEMiA. 4. Nephrolepis. 5. Oleandra. G. Fadyenia. 8. Onoclea. It is 

 true a synopsis of their character is not to be given a few words ; but they 

 appear to me to have sufficient marks of distinction natural or artificial. 



1. DlDYMOCHL^XA, DeSV. 



(Hook. Gen. Fil. tab. VIII.) 



Sori dorsal, terminal on a veinlet, elliptical. Involucre 

 elliptical, emarginate at the base, attached by a longitudinal 

 receptacle, free all round at the margin. Veins subflaljellate, 

 several times forked, free, the apices of the veinlets clavate. 

 ■ — Caudex erect, stout, arboreous. Fronds tufted, terminal, 

 A-Qfeet long, stipitate, erecto-patent, subcoriaceous, bipinnate. 

 Pinnules |-1 inch long, obliquely rhomboid. Sori submarginal 

 mostly on the superior half of the pinnule. 



1. D. lunulata, Desv. in Mem. Soc. Linn. vi. p. 282, 

 Hook. Gard. Ferns, pi. 17. D. sinuosa, Desv. I.e. p. .28. 

 Mart. Ic. PL Crypt. Bras. p. 95. t. 28 and 29. / 1. Hook. 

 Gen. Fil. t. 8. D. squamata, Desv. Journ. Bot. Appl. i. p. 5. 

 /. 2./. 4. D. truncatula, /. Sm. Gen. of Ferns, p. 84. D. di- 

 midiata, Kunze in Liuncsa, x\m. p. 122. Schk. Fil. Suppl. p. 

 200. t. 84. Pappe and Raws. Syn. Fil. Afr. p. 15. Aspidiuni 

 truncatulum, Siv. Syn. Fil. pp. 52 and 252. JVilld. Sp. PI. v. 

 p. 256. Aspid. squamatum, JVilld. Sp. PL v. p. 250. Mono- 

 chlecna sinuosa, Gaudich. in Freyc. Voy. Bot. p. 340. /. 12. 

 f. 3. Di})lazium pulcherrimum, liaddi, Fil. Bras. p. 42. t. 59. 

 Lonchitis ramosa, etc.. Plum. Fil. p. 43. t. 56. 



