HANDIiOOK OF liRiriSlI 11 KI'.\'IIC/K. 63 



Porella thuja, Dick^. 



Caespitose, stem ascending, subpinnately 

 branched, above convex, smooth, leaves closely 

 imbricated, lower lobe spreading, elongated, 

 recurved, entire; interior ovate, rather obtuse, 

 margin reflexed; stipules oblong, acute, entire, 

 margin reflexed, recurved at the apex ; pcri- 

 cha^tial lateral, emergent, leaves larger, ciliately 

 serrate. 



JungODiaiuiia thuja, Dicks. Cr^^pt. 4, p. 19; 

 'ra3dor Trans. Bot. Soc. Edin. 11., 116. 

 MadotJieca thiija^ Dumort. Comm., p. 111. 

 Porella thitjay Carr. and Pears. Exs. No. 46. 

 Jungermannia platyphylla v. thuja, Hook. 

 Jung. t. 40, fig. 



On stones by lake sides. 



Tufts wide, olive green, the older parts purplish 

 brown, shining, the shoots acuminated. In plants 

 with pcrichaitia the branches are very short. It ma}' 

 be known h'om P. platyphylla hy its greater size, its 

 shining surface, its acuminate shoots, its denser 

 structure, its perichaetia prominent beyond the stem 

 leaves, its pericha^tial leaves larger, wider, more di- 

 vergent, and always ciliately-serrate, its divisions less 

 regularly pinnate, the closer imbrication of the 

 leaves, and the more patent position of their 

 inferior lobes. — Taylor. [Plate 2, jig. 20.) 



Porella pinnata, Z/W. 

 Stems irregularly- pinnate, or subdichoto- 



