The Jungermannia Section of Liverworts. 33 



o 



found on walls and on decaying trunks of trees, but never 

 among mosses. 



In the next group having leaves triquaclrifid, and with 

 equal segments, Jungermannia piisilla, or the d.warf Junger- 

 mannia, may also now be found in fruit. It has a nearly 

 simple procumbent stem, short and stout, and its whole length 

 clothed with long purple radicles on the under side, and hav- 

 ing horizontal quadrate leaves, large in proportion to the 

 plant, closely set, and irregularly waved, bifid, or trifid ; the 

 anthers are scattered naked upon the stem, the fruit terminal, 

 with a campanulate perianth singularly large with a wide 

 spreading mouth, waved and cut, an involucre of four or five 

 subulate appendages, and a globose capsule, which instead of 

 being firm, is of peculiarly thin and fragile texture, nurturing 

 densely muricated spores, and, on their arriving at maturity, 

 bursting, not into the usual cross, but irregularly. Another 

 peculiarity of this singular little plant, a lover of moist shady 

 banks, especially in a clayey soil, is, that sometimes two or 

 even three capsules are thrown up from the same perianth. 



In the same group with Jung, pusilla we have Jungerman- 

 nia incisa, though the segments of its leaves are unequal, and 

 here and there toothed. It is a minute species, frequenting 

 wet bogs, with thickened creeping compressed radiculose 

 stems, and crowded pale delicate green foliage, waved, com- 

 plicated, or folded into itself, and cut, subquaclrate in form, 

 more or less spinuloso-dentate, the involucral leaves or bracts 

 similarly shaped, but much more plicate and dentated. The 

 perianth is short, ovate, plicate, and denticulated at the mouth. 

 It fruits in winter and spring, but the fruit is rare, though the 

 gemnige are abundant, and, as in Jungermannia ventricosa, they 

 collect into little balls on the tips of the leaves. Several varie- 

 ties of this species are noticed by Nees ab Bssenbeck, but as 

 they appear to us chiefly, if not entirely, foreign, we think it 

 unnecessary to point them out here. 



The next group contains those whose leaves are bifid, with 

 unequal segments, and conduplicate or longitudinally folded. 

 These are chiefly spring fruiters, except Jungermannia com- 

 jplanta, or the fiat Jungermannia, which bears fruit throughout 

 the year. It has a creeping vaguely -branched stem, with dis- 

 tichous leaves, imbricated above, unequally two-lobed, the 

 upper lobes larger and orbiculate, the lower ones ovate, ap- 

 pressed and plane. The perianth is oblong, compressed, trun- 

 cate, or seeming to terminate in a straight cross line. Like 

 Jungermannia dilatata, it is a parasite on the trunks of trees, 

 to the bark of which it is closely pressed, but in pale green 

 patches of an orbicular outline. 



We now come to the sub-section Stipulatee, comprehending 



