692 hepatic^:, (liverworts.) 



21. PLEURAKTHE, Tayl. (Tab. 21.).) 



Fructification lateral. Involucral leaves 3, minute, scale-like, 2-3-cleft. 

 Perianth elongated-fusiform, arising from the lower side of the stem, fleshy, 

 solid and rooting at the base, membranaceous above ; the mouth compressed 

 or triquetrous, 2 - 3-cleft, lacerate. Calyptra concrete with the perianth, except 

 at its apex. Capsule oval. Elaters with 2 spiral fibres. Antheridia unknown. 

 Leaves 2-lobed or emarginate. Amphigastria lanceolate, entire. (Name from 

 Trkfvpd, the side, and dvdos, a flower ; the perianth being lateral.) 



1. P. olivacea, Tayl. Grows in close olive-green mats; stems creep- 

 ing, 2" -3" long, mostly simple, rooting profusely; leaves rotund-oblong, up- 

 wardly secund ; pedicel 4" - 5" high : a small species, the perianth dispropor- 

 tionately large. — North America, Drumm ond. (Tab. 21.) 



22. LOPHOCOLEA, Nees. (Tab. 21.) 



Fructification terminal on the main stem or primary branches. Involucral 

 leaves 2-4, large. Perianth tubular below, acutely 3-angular above, 3-lobed ; 

 the lobes tooth-crested. Calyptra short, membranaceous, circumcissile at the 

 base, or rupturing irregularly at the apex. Capsule oblong. Elaters with 

 two spiral fibres. Antheridia in the saccate bases of perigonial leaves. Stem- 

 leaves decurreut on the dorsal side of the stem, flaccid, 2 - several-cleft at the 

 apex. Amphigastria 2-4-divided; the divisions more or less incised. (Name 

 composed of Xodjos, a crest, and KoXtos, a sheath ; from the crested calyptra.) 



1. 1L. MdCBttata, Nees. Stems (1 ' - 2' long) prostrate, sparsely branched ; 

 leaves pale green, ovate-triangular, spreading, 2-toothed at the apex ; the teeth 

 oblique, acute, with a crescent-like sinus ; amphigastria minute, about 4-cleft, 

 the segments entire. — Moist places, among Mosses. (Eu.) 



2. Sj. lieterophylla, Nees. Stems much branched, ascending ; leaves 

 ovate, subquadrate, semi-vertical, entire, retuse, and bidentate on the same stem ; 

 amphigastria large, 2-cleft, the segments slightly dentate. — On decayed logs, 

 and among Mosses. (Tab. 21.) (Eu.) 



23. SPHAGN<ECETIS,Nees. Peat Scale-Moss. (Tab. 22.) 



Fructification terminal, upon a short proper branch arising from the ventral 

 side of the stem. Involucral leaves small, few, incised. Perianth ascending, 

 terete, 3-angled at the apex ; the mouth denticulate. Calyptra membranaceous. 

 Capsule oblong. Elaters with two spiral fibres. Inflorescence monoecious : 

 antheridia in the axil of the minute perigonial leaves of pendent proper branches. 

 Stem leaves orbicular. Gemma? collected in heads upon the attenuated tips of 

 the branches. Amphigastria none, except upon the gemmiferous branches. 

 Stems furnished with runner-like rootlets. (Name composed of 2<fidyvos, Peat- 

 Moss, and koitis, a little bed; from its place of growth.) 



1. S. communis, Nees. Stems creeping ; leaves elliptical-orbicular 

 entire, ascending. (Jungermannia Sphagni of authors.) — Upon moss and de- 

 cayed wood. (Tab. 22.) (Eu.) 



