250 



MEMOIRS OF THE NEW YORK BOTANICAL GARDEN 



[VOL. 11 



rectangular in outline, concave to complicate, the keel broad to sharply acute, a 

 ventral wing from the keel absent or rudimentary, to large, three to five cells 

 wide and extending from the apex to the middle of the leaf or beyond (in one 

 species the wings in pairs), the lobes equal or the dorsal lobe larger, the margins 

 entire, crenulate, serrate, dentate or incised; the cell surface (ventral) plane, or 

 convex, or with a conspicuous mamillose projection, the cuticle smooth, verrucu- 

 lose, papillose or rough-warty. Underleaves similar to the leaves, or smaller, 

 orbicular, ovate, long oval, quadrate, or of only a few cells, in some species 

 showing a decrease in size from the base of the stem to the tip. Plants dioicous, 

 the sexual branches ventral from near the base of the leafy stem, more rarely 

 from the rhrizome. Male inflorescence slender, short (very rarely terminal on 

 the stem) , usually catkin-like, hyaline, the bracts and bracteoles in four to ten 

 series, smaller than the leaves and underleaves, the bracts concave, inflated, the 

 bracteoles, small ovate, plane; antheridia one or two, in the axils of the bracts. 

 Female inflorescence on a short sexual branch, without innovations, the bracts 

 and bracteoles similar, in 3-4 scries, different from the leaves, long ovate to 

 ovate-lanceolate, toothed to laciniate-ciliate above. Perianth 4-6 mm long, 

 terete below, trigonous and often with additional lobes above, the mouth 

 contracted, three-parted and fringed with numerous cilia or ciliate laciniae 

 Sporophyte capsule, long, red-brown. Spores small, red-brown. 



Type species: Jungermannia carinata Greville, Ann. Lyc. Nat. Hist. X. Y. 

 1: 276. 1825. 



The genus is abundant in wet forests of tropical South America and extends 

 southward into southern Brazil and northward into the West Indies. I have seen 

 no specimens from Central America. Some of the species are restricted locally 

 while others are widespread with seemingly several subspecies or varieties with 

 distribution patterns which apparently overlap to some degree. Except for 

 those species in which the stems with leaves tend to be radial the genus is 

 readily recognized by the folded, flattened leaves with a conspicuous wing, and 

 the flattened leafy stems from a prostrate rhizome system. Within the species 

 there is a high degree of variability in size of leaves, configuration of the 

 margin, length and width of the wing, size of the mamillose projections, and the 

 smoothness or "wartyness" of the cuticle. The underleaves vary greatly in size 

 and shape on any stem, and in certain species, characteristically show a gradual 

 decrease in size from the base to the apex of the stem. 



Key to the Species 



1. Leafy stems more or less radially symmetric, underleaves large, little different from 

 the leaves in size and form; a wing absent or poorly developed on the upper part 

 of the leaf (in M. steyermarkii as long as the leaf). 

 2. Leaves orbicular to broadly ovate; underleaves orbicular to ovate-truncate; 

 plants tiny, slender. 



3. Leaf cells 9-12 p, the cuticle smooth to faintly verruculose. 1. M. surinamense. 



3. Leaf cells 15-20 p. 



4. Cells without mamillose projections, cuticle rough-warty. 2. M. duidae. 



4. Cells with very large mamillose projections, cuticle rought-warty. (small 



plants of) 11. M. bolivarense. 



2. Leaves ovate to lanceolate, acute to acuminate. 

 3. Leaf cells mamillose; leaves and underleaves widely spreading, the margins 



crenulate-mamillose; the wing as long as the leaf. 16. M. steyermarkii. 



3. Leaf cells not mamillose, the cuticle smooth to faintly verruculose; a wing 

 absent or short. 



