686 (86) HEPATic-s;. (liverworts.) 



SuBOEDEK m. MARCHAWTIACEiE. 



Frondose and terrestrial perennials, furnished beneath with imbricating 

 colored scales, and numerous tubular radicels tuberculate -within ; recepta- 

 cle raised on a peduncle springing from the apex of the frond (also from 

 the back, in No. 12), capitate or radiate, bearing from the under side pen- 

 dent calyptrate capsules -which open variously, but are not regularly 

 4-¥alved : elaters with two spiral fibres. 



5. MARCHAWTIA, L. Brook-Liveewoet. (Tab. VI.) 



Pertile receptacle radiated. Involucres alternate with the rays, 2-valve(3, 

 lacerate ; enclosing 3-6 one-fmited 4 - 5-cleft perianths. Calyptra opening at 

 the apex, persistent. Capsule globular, pendulous, exsertly pedicelled, dehiscing 

 at the apex by several revolute segments. Spores smooth. Elatei-s long, slen- 

 der, and attenuated at each end. Inflorescence dioecious. Steiile recei^tacle 

 peduncled, shield-hke, lobed or rayed, papillose on the upper surface by the sum- 

 mits of the immersed antheridia. Lentil-shaped gemmce in cup-like receptacles 

 on the back of the frond. Prond expanded, forking, with a broad diffused mid- 

 rib. (Named after Nicholas Marchant, a French botanist.) 



1 . IS. polymorplaa, L. Fertile receptacle deeply divided in a star-like 

 manner; the rays 8-10, terete. — Shaded and moist places; very common. 

 (Tab. VI.) (Eu.) 



2. M. clisjuncta, Sulhv. (Mem. Amer. Acad. 1. c. p. 63, t. 3.) Fertile 

 receptacle |-chcu]ar, radiately 7 - 9-lobed ; the lobes cuneate, crenulate on the 

 outer margin; sterile receptacle digitately lobed: about the size of No. 1. — 

 Springy places, banks of the Alabama Eiver, near Clairbom-ne : fruiting in May. 



6. PREISSIA, Nees. (Tab. VI.) 



Fertile receptacle hemispherical, 2 - 4-lobed, with as many rib-like rays alter- 

 nating with and shorter than the lobes. Involucres attached to the under side of 

 the lobes, 1 - 3-fraited, opening beneath by an irregular line. Perianth obconic- 

 campanulatc, angular, unequally 4 - 5-lobed. Calyjiti-a persistent, opening ob- 

 liquely. Capsule large, pedicelled, dehiscing by 4 - 5 revolute segments. Spores 

 tuberculate. Elaters short. Inflorescence dioecious, rarely monoecious. An- 

 theridia immersed in a peduncled peltate receptacle. Frond sparingly forked, 

 increasing by joints from the apex. (Named for L. Preiss, a Gennan botanist.) 



I. P. commutata, Nees. Fertile receptacle somewhat angled by the 

 prominent keel-like rays ; capsule conspicuous, dark purple. — Shaded, moist 

 places, Niagara Falls (Careij), Lake Superior (JLoring), &c. (Tab. VI.) (Eu.) 



7. DUMORTIERA, Nees. Haiet Liveewoet. (Tab. VL) 



Fertile receptacle convex, 2-8-lobed. Involucre 1 -fruited, opposite to and 

 connate with the lower sm-face of the lobes, horizontal, oblong, opening by a 

 vertical slit at the outer extremity. Perianth none. Calyptra obovate, rupturing 



