The Jungermannia Section of Liverworts. 331 



Jungercnanniae. Hooker places tlie genus between the Mar- 

 chantia and the Lichens; Grottshe, Lindenberg, and Nees ab 

 Esenbeck between Scapania and Sphagnascetis. 



With leafy developments of every imaginable variety of 

 forni, with usually extreme delicacy of texture and a perfection 

 of cellular tissue, they have, with few exceptions, a terminal 

 pericliEetiuin, perianthium, or perianth, as it is commonly called 

 in this genus, of a tubular form ; monophyllous ; from the base, 

 or only towards the apex, angularly folded, and splitting even- 

 tually into from three to six lacinated or toothed membrana- 

 ceous portions, free or rarely united to the involucrum, except 

 at the base. The perianth is sometimes double, seldom want- 

 ing, and the leaves of the involucrum, which surround its 

 base, are for the most part distinct. The peduncle, or fruit- 

 stalk, varies in length from a few lines to two inches or more, 

 but is longer than the perianth, of an almost transparent sub- 

 stance, composed of oblong cells, and bearing on its summit 

 the hard, firm capsule, which is, even to its base, quadrivalve, 

 and when mature, being destitute of an operculum like the 

 mosses, it splits its whole length to give exit to the young- 

 spores and elaters contained within ; and once open, it has no 

 power to close, but remains expanded, like a minute brown 

 cross on the summit of the peduncle, till age or other cause 

 dethrones it to commingle with the soil again. Before the 

 splitting of the capsule, the elaters are doubly coiled or writhed 

 like a rope rolled up in the interior ; but they are very fugace- 

 ous, and no sooner does the capsule open, than they spring 

 forward to bear the nursling sporules out to seek their fortune 

 in the wide, dank earth. 



The genus is monoicous, or rarely dioicous ; the anthers 

 are globose with short filaments. The stems are creeping or 

 prostrate, either simple or branched. 



The genus has numerous species ; Lindenberg, in his 

 Synopsis Hepaticarum, enumerates 137, chiefly European and 

 American. For instance, 85 are indigenous to Europe and its 

 islands ; only 15 had then been discovered in tropical Asia, 9 

 in Southern Africa, 8 in New Holland and Australia, in tropi- 

 cal America 15, and 3 in North America, including Greenland. 

 Besides which there are many species, which other authors 

 assign to this genus, that are distributed by him among differ- 

 ent genera of the, Hepaticse. They are terrestrial plants, or 

 parasitic upon trees or among mosses ; some of them showy, 

 some slender and inconspicuous, chiefly perennial, perhaps 

 none either annual or biennial. The texture of the leaves 

 herbaceous, with large net-work, especially in the sub-tribe 

 Bicuspidatum. But they are divided into two grand sections — 

 the Foliaceous, which have distinct stems and leaves of delicate 



