484 HEPATICJE. 



1. Riccia glauca, Linn. 



liiccia ylaiica, Linn. Sp. pi. iCO.') (17");)), 



Monoicous, growing in orbicular patches, closely attached to 

 the ground, small, glaucous green in colour, concolorous. Fronds 

 bifid or dichotomous, substellate, lobes linear, obovately-linear or 

 cuneate^ 8 to 12 cells thick near the middle, plane or channelled 

 near the apex, punctate, apex emarginate or obtuse, margin thin, 

 membranaceous, crenulate or smooth, postical side green ; radi- 

 culose, rootlets plentiful ; texture fleshy ; cells hexagonal or sub- 

 quadrate, walls thick, no trigones. Capsules subspherical in a 

 sinorle or double row radiatincr from the centre of the frond and 



O C) 



runnino; alons: near the middle of each lobe, crowned with a style, 

 4 to 6 cells long, of a dark colour, which alone is protruded, and 

 soon deciduous. Spores dark reddish-brow^n, almost black when 

 ripe, angular-globose, reticulate, walls of convex side irregularly 

 tuberculate, papilke narrowly conical, areolae regular, 5, 6-angled, 

 8-10 measuring the convex surface, other sides almost smooth ; 

 when young with a narrow pellucid border, scarcely visible when 

 ripe. 



Var. minima. Minute, green on both sides, fronds bifid, lobes 

 linear, thin, 4 to 6 cells thick, plane, slightly channelled near 

 apex. 



Dimensions. — Plants \ to J inch in diameter ; fronds 6' mm. 

 X 2- mm., 7 mm. thick, 5' mm. x l" mm., "5 mm. thick ; capsule 

 '6 mm. ; spores '09 mm. x '07 mm. 



Var. minima, \ inch in diameter; fronds 1-75 mm. x '5 mm., 

 •3 mm. thick, 2*25 mm. x '6 mm., "3 mm. thick, 3*5 mm. x "7 mm., 

 '3 mm. thick. 



Hab. — On moist ground, chiefly clayey fields and gardens. 



1-16. I. Common; rarer in Scotland. 



Europe, Asia, Japan, North America. 



Var. minima. Probably generally distributed. 9. Stretford, 

 Lane, C. J. Wild; Cheetham, Lane, C. J. Wild. 12. Fowlshaw 

 Moss, Westmorland, G. Stabler, 



