13. DICKSONIA, § CIBOTIUM. 49 



S-4 in. 1., bipinnate ; pinnae lanceolate, sessile, the central |-^ in. 1., cut down lo 

 the rachis oi- a narrow wing into blunt oblong crenate lobes, the lower distant 

 gradually reduced ; rachis stramineous ; Uxtwre moderately firm ; both sides green, 

 glabrous ; sori submarginal ; inv. minute, hidden by the sorus, obscurely ciliated. 

 —Canad. Nat. 1865, p. 90. 



Hab. Eocky Mountains ; Oregon and Lake Winnipeg. — Close to oUusa, from which 

 it differs by its glabrous surfaces and smaller involucre. 



> Gen. 12. Sph^ropteris, Wall. 



Sori globose, on the back of a vein or veinlet. Recept. large. Invol. inferior, 

 globose, coriaceous, stipitate, at first enclosing the whole sorus, at length bursting 

 vertically i^ito 2 spreading lobes or lips. Tab. 1. f. 12. 



1. S. larhata. Wall. PL Asiat. Bar. 1. *. 18. Hk. Sp. 1. p. 58. Peranema 

 cyatheoides, D. Don, Prodr. Nep. 12 (oldest name). 



Hab. Nepal, Sikhim, Khasya (Hie. f. and Thorns.), Western Ghats of Nilghiri, 

 Bcddome. — Fr. 2-3 ft. 1., tripinnate. Pinnl. oblong, deeply pinnatifid. 



Gen. 13. Dicksonia, X'//ln«.- (See p. 460.) 



Sori placed at the apex of a vein, intra-marginal. Invol. inferior, subglobose, 

 coriaceous or membranaceous, cup-shaped and entire, or more or less distinctly 

 2-valved. — Ahout half the species are arborescent, with large decompound coriaceous 

 fronds ; the others have creeping rhizomes, and, loith two exceptions, are at least 

 fidk/ bipinnate. They principally inhabit Tropical America and Polynesia ; hut one 

 species reaches as far north as Canada, and several others are scattered throughout 

 the southern parts of the Temperate Zone. Veins in all free. Tab. II. f. 13. 



§ Cibotium, Kaulf. — InMlua-e distinctly 2-valved, the outer valve coriaceous, 

 distinct from the substance of the frond, Sp. 1-6. 



1. D. (Cibotium) glauca. Smith ; arborescent ; fr. trpinnate, ovate-lanceolate, 

 12-18 in. 1., 6-9 in. br. ; pinnl. linear-acuminate, cut quite down to the rachis in 

 the lower part ; lohes linear-oblong, subfalcate ; texture subcoriaceous ; surface 

 naked on both sides, glaucous beneath ; veins prominent ; lateral veins of the 

 segments once or twice forked ; sori 2 to 12 to a lobe, inner valve oblong, nar- 

 rower than the outer. — Hi. Sp. Fil. 1. p. 82. t. 29. A. 



Hab. Oahu, Sandwich Islands, discovered by Menzies eighty years ago. 



2. D. {Cibotium') Barometz, Link ; arborescent ; fr. trpinnate ; lower pinnce 

 ovate-lanceolate, 1-2 ft. 1., 6-12 in. br. ; pinnl. linear-acuminate, cut down within 

 a short distance of the rachis above, and sometimes quite down to it at the base ; 

 segm, linear-oblong, acute, subfalcate ; texture subcoriaceous ; upper surface 

 naked, shining, lower glaucous, sometimes f urfuraceous ; veins prominent ; lateral 

 veins oi the segments rarely forked ; sori 2 to 12 to a lobe, the valves nearly equal, 

 transversely oblong. — C. glaucescens, Hh Sp. Fil. 1. ^. 82. C. Assamioum, 

 Hk. Sp. Fil. 1. p. 83. t. 29. B. C. glaueum, Bedd. Fil. Brit. Ind. t. 83. 



Hab. Assam, S. China, Malayan Peninsula and Islands. 



3. D. {Cibotium) Mendesii, Hook, and Baker; fr. tripinnate; lower pinnce 

 12-18 in. 1., 6-9 br. ; pinnl. linear-acuminate, cut down usually not more than 

 half-way to the rachis ; lobes rounded, blunt ; texture subcoriaceous ; surface 



o 



