518 JUNGEEMANNIACEAE. 



1. Archilejeunea viridissima (Lindenb.) Evans, Bull. Torr. Club 35: 169. 1908. 



Lejeunea viridissima Lindenb. in G L. & Syn. Hep. 320. 1845. 



Yellowish or brownish green, becoming darker with age, neither glossy nor 

 glaucous, growing in depressed mats; secondary stems simple or sparingly 

 branched, often with poorly developed lobules. Leaves with broadly ovate dor- 

 sal lobes, about 0.75 mm. long; lobule (when well-developed) bearing two 

 teeth, the outer or apical often variously curved and longer than the inner 

 tooth; leaf -cells averaging about 24 X 18 n; underleaves distant to loosely im- 

 bricated, broadly orbicular-ovate, cuneate, rounded to subretuse ; inflorescence 

 autoecious. Female inflorescence usually with a single subfloral innovation, the 

 bracts very deeply bilobed; perianth oblong-obovate, the wings usually distinct 

 but narrow, sinuate or subcrenulate. 



On bark, Eight Mile Rocks, Great Bahama : Jamaica ; Porto Rico ; Venezuela. 

 Greenest Archilejeunea. 



18. LEUCOLEJEUNEA Evans, Torreya 7: 225. 1908. 



Plants medium-sized to large, pale green or glaucous, neither glossy nor 

 pigmented, prostrate, copiously branched, the branches as in Eadula. Leaves 

 imbricated, complicate-bilobed, the dorsal lobes not squarrose when moist, 

 ovate-oblong to suborbicular, convex and often revolute along the lower margin 

 and in the region of the rounded apex, entire or nearly so; lobule inflated 

 throughout, the margin more or less involute, entire except for the single blunt 

 to acuminate apical tooth with the hyaline papilla at the distal base; leaf- 

 cells with small trigones. Underleaves orbicular to reniform, undivided. An- 

 theridia borne in pairs in the axils of saccate bracts, the androecia short, not 

 proliferating; bracteoles restricted to the base. Female inflorescence borne on 

 a branch variable in length, innovating on one or both sides; bracts with plane 

 lobules, otherwise similar to the leaves. Perianth five-keeled, scarcely com- 

 pressed, the keels smooth or obscurely crenulate or denticulate, rarely with 

 indistinct wings. [Greek, white Lejeunea.] A small genus, consisting of about 

 6 species, of tropical and temperate regions. Type species: L. clypeata 

 (Schwein.) Evans. 



Dorsal lobes slightly convex or plane, not revolute ; apex of 



lobule easily seen. 1. L. unciloba. 



Dorsal lobes strongly convex and revolute ; apex of lobule not 



easily seen except by dissection. 2. L. xanthocarpa. 



1. Leucolejeunea unciloba (Lindenb.) Evans, Torreya 7: 228. 1908. 



Lejeunea unciloba Lindenb. in G. L. & N. Syn. Hep. 331. 1845. 



Pale green and glaucous, growing in depressed mats. Leaves closely im- 

 bricated, the dorsal lobe plane or slightly convex, ovate-oblong, about 1.2 mm. 

 long; lobule inflated toward base, the margin plane except at the base, the 

 apical tooth acuminate and sometimes hamately curved, usually three to six 

 cells long, easily visible without dissection; leaf -cells averaging about 18 fi in 

 diameter; underleaves broadly orbicular to reniform; inflorescence autoecious. 



On bark, Soldier's Road, New Providence : Rhode Island south to Florida and 

 west to Texas ; widely distributed in tropical America. Hook-lobed Leucolejeunea. 



2. Leucolej eunea xanthocarpa (Lehm.& Lindenb.) Evans, Torreya 7: 229. 1908. 



Jungermannia xanthocarpa Lehm. & Lindenb. Pug. 5: 8. 1832. 

 Strongly resembling L. unciloba in size and general appearance and agree- 

 ing with it in inflorescence. Distinguished by its strongly convex leaf lobes 



