1962] 



LEAFY HEPATICAE OF LATIN AMERICA — PART I 



41 



male bracteole, the tips expanded as disc-shaped plates, sometimes fused. Line 

 of leaf insertion oblique, the leaves suecubous. Leaves subquadrate to ovate or 

 broadly orbicular, symmetric or asymmetric, with the ventral portion longer, 

 divided into three to nine triangular, often branched, ciliate segments, the cilia 

 occurring singly and opposite or whorled, the cells long, narrow, the cuticle 

 striolate-papillose. the lamina quadrate, rectangular, or irregular in outline, 

 occasionally with superficial cilia over the surface. Underleaves transversely 

 inserted, a little smaller to only one-half as wide as the leaves, bisbifid or quad- 

 rifid to one-half or more of their length, the four segments branched and ciliate 

 as in the leaves. Plants dioicous. Male inflorescence terminal becoming inter- 

 calary on the stem or branch, the bracts and bracteoles in to 15 or more series, 

 as large as or larger than the leaves, the bracts concave, the lamina long, the 

 cilia shorter than those on the leaf ; antheridia large, globose, one or two in the 

 axils of the bracts, the stalk long. Female inflorescences terminal on a stem or 

 branch, becoming lateral or axillary through the development of one or two 

 lateral subfloral innovations which may in turn become floriferous, the bracts 

 and bracteoles similar to but more elaborate than the leaves and underleaves, 

 in three series, the inner series the largest and larger than the leaves; arche- 

 gonia 8-20 or more, surrounded by many paraphyllia. Perianth present or 

 absent. Sporophyte enclosed in a shoot-calyptra and perianth (T. tomentosa) ; 

 or a coelocaule (formed of the shoot and calyptra) either incomplete, a crypto- 

 coeloeaule, with a thickened hollow stem below and a very small shoot-calyptra 

 surrounded by a very short perianth at the top, or complete, an epicoeloeaule, 

 covered with paraphyllia, scales, and with unfertilized archegonia at the top. 

 The sporophyte foot inverted cone-shaped with a high collar ; seta in transverse 

 section of small firm-walled outer cells surrounding the larger delicate-walled 

 inner cells which soon disintegrate. Capsule oblong, the wall of six or seven 

 layers of cells, the cells of the outer layer large, thin-walled, soon disappearing, 

 the cells of the inner layers smaller, with rod-shaped, reddish-brown thickenings 

 on the tangential walls ; elaters long slender, reddish-brown, with two or three 

 spirals, the ends blunt or tapering ; spores 30-35 /a, reddish-brown. Protonema 

 of the NarMa type. Gemmae not seen. 



Type species: Jungermannia tomcntella Ehrhart, Beitr. Naturk. 2: 150. 1788. 



The genus, with some twenty species, is mainly in the Southern Hemisphere. 

 Only one species is found in North America and it does not extend into the 

 Southern Hemisphere. From a developmental point of view the genus is of 

 interest in that there are three types of shoot-sporophyte relationships devel- 

 oped among species which are otherwise very similar. 



Key to the Species 



1. Leafy stems with few to many paraphyllia. 



2. Leaves divided to one-half of their length into six or eight very densely ciliate 



segments. 4. T. robusta. 



2. Leaves divided to one-half of their length into four or five sparsely ciliate segments. 



5. T. paraphyllina. 



1. Stems without paraphyllia. 



2. Plants very small, filiform; leaves with only three segments. 12. T. filicaulis. 



2. Plants larger; leaves with more than three segments. 



3. Leaf lamina less than half as high as wide, mostly only one to three cells high. 

 4. Plants small; leaves approximate to spreading. 



5. Cells of the leaf lamina mostly 55 X 18 m. 10. T. floccosa. 



5. Cells of the leaf lamina mostly 90 X 30 fi. 11. T. sprucei. 



4. Plants large; leaves imbricate, appressed. 



