202 



taper outwards to the acuminate point. The fertile fronds are taller 

 and on longer stipites than the sterile. 



Genus XXVII. Gymnogramme, Desv. 



Sori oblong, linear-oblong or linear, situated on the back of the veins^ 

 superficial or somewhat immersed ; veins free or united ; fronds rang- 

 ing from simple to decompound, naked, ciliate. or coated beneath with 

 white or yellow powder. 



This is a genus of rather considerable extent, in which very dis- 

 similar plants are associated by the common character of superficial or 

 immersed naked elongated sori. In the form and arrangement of the 

 sori it resembles Asplenium, of which in this division it may be 

 regarded the anologue, differing by the absence of involucres. The 

 farinose section is remarkable for a fecundity equalled by very few 

 other plants in the family. The species are about equally divided 

 between the old and the new "World and are chiefly tropical. They 

 occupy banks and usually open, generally fully exposed, situations, and 

 are represented abundantly from the lowest to the highest elevations. 

 Fronds flabellato-digitate. — 1. G. pumila. 



Fronds simply pinnate. — 2. G. rufa. 



Fronds bipinnatifid — 3. G. gracilis. 



4. G. consimilis. 



5. G. diplazoides. 

 Fronds decompound. — 6. G. chserophylla. 



7. G. scbizophylla. 



Fronds coated with powder beneath. — 



Pinnso trifoliate. — 8. G. trifoliata. 



Fronds decompound. — 9 G. tartarea. 



10. G. triangulata. 



11. G. calomelanos. 



12. G. sulphurea. 



1. G. pumila, Spreng. — Rootstock filiform, erect, clothed with hair- 

 like reticulated ciliate-edged brown scales ; fronds membranous, glossy, 

 naked, green, tufted, few, v-shaped or flabellate-cuneate, occasionally 

 linear-cuneate, \-\\ in. 1. 1-6 li. w. at the apex, the lateral margins en- 

 tire, the outer jagged or deeply incised, often into narrow spreading 

 sharp-pointed segments and gradually attenuated downwards to a slen- 

 der filamentose base with hardly any clear stipites ; veins close, flabel- 

 late, dichotomously forked ; sori linear, becoming confluent laterally, 

 forming one or more broadish patches on the more entire portion of the 

 outer parts of the fronds. Hook. 2nd Cent. Ferns t. 8. Hecistopteris, 

 J. Smith. 



var. a. — Fronds shorter and broader and deeply cut into spreading 

 linear segments, which divaricate like stag's horns. 



Communal, forming large or small patches in moss on the trunks of 

 trees ; gathered by March, whose specimens are at Kew. It varies 

 greatly in shape and degree of cutting from linear with two or three 

 sharp segments or teeth at the apex, to broadly palmate flabellate and 

 multifidly cut to the base. The lines of sori are at first separate but 

 ultimately unite laterally, forming apparently amorphous patches ; but 

 in var. a there are only one or two lines to each narrow segment. 



2. G. rufa, Desv. — Eootstock fibrous, upright ; stipites tufted, erect, 

 chestnut brown, polished, rusty villose, 4-10 in. 1.; fronds pinnate, thin 



