506 JUNGEEMANK1ACEAE. 



bracts saccate at the base, the bracts imbricated and usually arranged in elon- 

 gated androecia, often proliferating at the apex. Perichaetial bracts similar 

 to the leaves but often broader and more toothed. Perianth laterally com- 

 pressed, the mouth broad, truncate, and variously dentate to ciliate. [Greek, 

 oblique lip.] Some 800 species or more, mostly tropical. Type species: P. 

 asplenioides (L.) Dumort. 



1. Plagicchila ludoviciana Sulliv. Muse. Alleg. 223. 1845. 



Loosely tufted, yellowish to brownish green. Stems sparingly and irregu- 

 larly branched. Leaves obliquely spreading, imbricated, about 2.5 mm. long 

 and 1.2 mm. wide, ovate, long-deeurrent dorsally and reflexed at the ventral 

 base, irregularly toothed in the apical region and along the ventral margin; 

 underleaves minute or larger and narrowly lanceolate. 



On bark. Maidenhead Coppice, New Providence : Louisiana to Florida ; Cuba ; 

 Virgin Islands. Louisiana Plagiochila. 



2. RADULA Dumort. Comm. Bot. 112. 1822, 



Stems prostrate or growing from a prostrate rhizome, with numerous lat- 

 eral branches arising just behind normal leaves; rhizoids always borne on the 

 ventral lobes of the leaves. Leaves complieate-bilobed, the dorsal lobes larger 

 than the ventral, incubous, usually entire and often rounded at the apex; ven- 

 tral lobes attached to the dorsal by a more or less elongated keel, the free 

 margin usually appressed to the dorsal lobe. Underleaves none. Antheridia 

 borne singly or in groups of two or three in the axils of saccate bracts, the 

 latter forming more or less elongated androecia. Archegonia borne on more or 

 less elongated branches, sometimes with subfloral innovations; bracts similar 

 to the leaves. Perianth usually dorsiventrally compressed, rarely subterete or 

 plicate, truncate and bilabiate but otherwise entire at the broad mouth. Gem- 

 mae, when present, discoid, multicellular. [Latin, a scraper or spatula.] About 

 400 species, largely tropical. Type species: B. complanata (L.) Dumort. 



1. Radula australis Aust. Bot. Bull. (Bot. Gaz.) 1: 32. 1875. 



Plants dark green, loosely tufted to scattered. Stems irregularly pinnate. 

 Leaves imbricated, the dorsal lobe spreading at about a right angle, obovate- 

 oblong. about 1 mm. long and 0.6 mm. wide ; lobule rhomboid, rounded at the 

 apex, the upper margin parallel with the keel; inflorescence dioecious; androe- 

 cium mostly median, the bracts in about six pairs; perianth elongated. 



On bark, Andros and New Providence : Georgia and Florida. Southern Radula. 



3. DIPLASIOLEJEUNEA [Spruce] Sehiffn. in E. & P. Nat. 

 Pflf. I 3 : 121. 1894. 



Stems prostrate, copiously branched, the branching as in Radula. Leaves 

 loosely imbricated, complieate-bilobed, the dorsal lobe ovate to orbicular, at- 

 tached by a very short base, convex and widely spreading, entire; lobule in- 

 flated, attached to the dorsal lobe by a long arched keel, usually with two dis- 

 tinct teeth in the apical region ; leaf-cells with more or less thickened walls, 

 scattered ocelli usually present. Underleaves doubled, one for every lateral 

 leaf, deeply bifid with divaricate lobes. Antheridia borne in pairs in the axils 



