8 HEPATIC^E. 



opposite and connate with the intervening stipules ; closely 

 imbricate, bilobed. Antheridia solitary, large, oval-globose, 

 stipitate, situated in the saccate bases of the bracts. 



1. Porella laevigata (Sc/irad.) Lindb. 



Jungermania IcBvigata, Schrad. Syst. Samm. 11, n. 104, p. 6 (1797); Hook. 



Brit. Jung. t. 35 (181(5). 

 Madotheca Icevigata, Dum. Comm. p. Ill (1822). 

 Porella Icevigata, Lindb. Muse, scand. p. 3 (1879). 



Dioicous, loosely csespitose, largish to large, olive-green to 

 yellowish-brown. Stems procumbent, lying over each other in an 

 irregularly imbricated manner, irregularly bipinnate, branches 

 horizontal, irregular in size, number and position, apices somewhat 

 attenuate ; on a cross-section oval, frontally compressed, 24 cells 

 X 32, the cortical and next inner layer of cells being small with 

 very thick brown walls, the third row having brown walls but 

 thinner, and the inner cells becoming gradually larger with 

 thinner and more hyaline walls ; radiculose, rootlets few, very 

 small, proceeding from the lower part of the stem. Leaves 

 closely imbricate, alternate, appressed to stem, incubous, bifarious, 

 unequally bilobed, antical lobe much the largest, horizontal, 

 convex or subplane, obliquely ovate, acute or acurainulate, margin 

 more or less entire, near antical base often furnished with 2 or 3 

 teeth ; postical lobe erect or erecto-patent, almost parallel with the 

 stem, oblong, plane, appressed to antical lobe, about as long but 

 narrower than the stipules, ciliate-dentate. Texture somewhat 

 thin, epidermis polished, rarely dull ; cells small, roundish, trigones 

 distinct. Stipules appressed to stem, broadest at the base, slightly 

 decurrent, ovate-rectangular, apex subtruncate, margin undulate, 

 ciliate-dentate. Flowers $ produced on short branchlets at right 

 angles to the branches ; sub-bracts somewhat similar to the 

 leaves only larger and ciliate dentate ; sub-bracteole similar to 

 stipules only larger; bracts patent- divergent, much larger than 

 the leaves, antical lobe broadly ovate, rotundate, ciliolate ; 

 postical lobe patent- divergent, broader than the leaf lobules, 



