208 CRYPTOGAMIA FILICES. [CI. 24. 



green or deciduous. Frond with a simple or alternately branching 

 stalk ; the leaf ribbed, veiny ; either simple or variously divided ; 

 bearing the fructification at the back, very seldom at the edges. 

 The membranous Cover, or Involucrum, which protects the masses 

 of capsules till they arrive at maturity, affords highly useful cha- 

 racters for distinguishing and establishing the genera.] 



463. POLYPoDIUM. Capsules in roundish scattered masses. Cover 



none. 



464. ASPlDIUM. Caps.'m roundish scattered masses. Cover nearly 



orbicular ; fixed by the centre, separating all round. 



465. CYSTeA. Caps, in roundish scattered masses. Cover orbicular, 



concave ; fixed by a lateral point underneath, finally reflexed 

 and jagged. 



471. WoODSI A. Caps, in roundish scattered masses. Cover round- 



ish ; fixed by a central stalk under each mass ; the margin in 

 numerous, deep, capillary, incurved segments. 



466. ASPLENIUM. Caps, in linear, scattered masses. Cover linear, 



separating at the side towards a midrib or vein. 



467. SCOLOPeNDRIUM. Caps, in nearly linear, twin, scattered 



masses, between 2 parallel veins. Covers 2, linear, opposite, 

 folding over each other. 



468. BLeCHNUM. Caps, in linear, solitary masses, close to the 



midrib. Cover linear, flat, separating towards the rib. 



469. PTeRIS. Caps, in linear, nearly marginal masses. Cover from 



the inflexed margin of the frond, wavy, continuous, separating 

 at its inner edge. 



470. ADlANTUM. Caps, on the back of each rounded, reflexed, 



marginal, distinct cover, in small, roundish, central masses. 



472. TRICH6MANES. Caps, in oblong masses, imbedded in the 



edge of the frond. Cover marginal, pitcher-shaped, of one 

 leaf, opening outwards. 



473. HYMENOPHfLLUM. Caps, in roundish masses, imbedded 



in the edge of the frond. Cover marginal, compressed, of two 

 valves, opening outwards. 



Capsules, or seeds, without any distinct elastic ring. 



[Habit various ; mostly herbaceous, and growing in or near watery 

 places.] 



478. EQUISeTUM. Catkins terminal. Seeds separately embraced 

 by 4 spiral filaments, presumed to bear pollen. — Subord. 

 Equisetace^e. 



476. OPHIOGLoSSUM. Spike 2-ranked. Caps. bivalve, imbedded. 

 — Subord. Filices ver^e. 



474. OSMuNDA. Cluster branched. Caps, stalked, naked, globular, 



with a striated protuberance. — Subord. Filices verjE. 



475. BOTRyCHIUM. Commonstalk compound, flattened. Caps. 



sessile, naked, globular, simple. — Subord. Filices ver^e. 



