24G HEPATIC^. 



prostrate and radicalose or ass argent and sub-erect, all lateral or 

 postico-lateral, eflagelliferous. Leaves moderately large, delicate, 

 in all European species alternate, in several tropical ones opposite, 

 succubous, antical margin much decurrent, postical shortly 

 arcuately inserted, oblique, ovato-oblong or very often sub- 

 triangular, apex broadly truncate, erect, exciso-bidentate or bi- 

 apiculate, rarely perfectly explanate, often convex or decurvulate, 

 rarely recurvo-secund ; antical margin somewhat straight, prin- 

 cipally recurved at the base, postical rotundate or somewhat 

 straight, margin entire, or in a few species more or less serrulate, 

 ciliate or spinose. Cells rather large or medium size, rarely small, 

 leptodermous, in a few species with the angles thickened. Stipules 

 everywhere present, 2-4 times shorter than the leaves, cuneate or 

 subquadrate, bifid, sometimes unidentate on both sides. Inflor- 

 escence dioicous or monoicous (very rarely paroicous). Androecia 

 on the middle or ends of the branches, rarely the whole length ; 

 bracts several pairs, small, above recurved, bifid, antical lobule 

 turgid, incurved, unidentate, antheridium solitary, large. Flowers $ 

 terminal on the stem or branches (rarely abbreviated) ; bracts 

 about 3 pairs, but little different from the leaves, slightly larger, 

 more frequently laciniate or spinose ; bracteoles a little shorter, 

 apex some^vhat conformable to the leaves, very often free, or only 

 at the base connate with one of the bracts. Pistillidia 18-60. 

 Perianth emersed, trigono-prismatic, often oblong 2-4 times 

 longer than broad, rarely shorter and urceolate, angles (antical. 

 above the others) in tropical species very often dentato-alate, 

 almost always in European species wingless, in a very few species 

 with a facial crest added ; mouth trifid (trilabiate), lips bifid, very 

 often laciniate or ciliate, leptodermous, only towards the base bi- 

 (at the angles tri-) stratose. Calyptra about half the size, obovate, 

 delicate, afterwards lacerated at the apex, surrounded at the base 

 by the sterile pistillidia. Capsule on a long pedicel, oblong- 

 globose, dividing to the base into 4 valves, 5-strata. Elaters 

 elongate, bispiral. Spores minute, smooth. 



