1962] 



LEAFY HEPATICAE OF LATIN AMERICA — I'AKT I 



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or ventral branch, the bracts and braeteoles similar, in three to six series, in- 

 creasing in size and decree of marginal serration from the leaves to the perianth, 

 paraphyses often present among the braets. Perianth fusiform, more or less 

 3-keeled, the third keel ventral, with three supplementary folds, divided to the 

 middle into three bilobed (trilobed) divisions; slime papillae on the margins 

 and surface of the segments. Xhoot/sporophyte relationship a shoot-calyptra. 

 Sporophyte capsule spherical, dark brown to black, the wall to 100 ft thick, of 

 five to seven layers of cells, the outer layer with characteristic red-brown knots 

 on the outer radial walls, the innermost layer with half-rings on the inner tan- 

 gential wall; elaters bispiral to the tips. Spores yellow to brown. Vegetative 

 reproduction by means of leaf cladia from single dedifferentiated cells of old 

 leaves and underleaves. 



Type species: Jungermannia juniperoidea Swartz. 



The genus is readily recognized in the field because of its large size, habit, 

 and the three rows of very similar, deeply bifid leaves and underleaves. For 

 the most part, the species are more difficult to separate, since the most depend- 

 able diagnostic characters are microscopic. 



There is considerable variation within any species, mostly in the size of the 

 stems, the length of the leaves and underleaves, the number of appendages on 

 the margins of the lamina of the leaves and underleaves, and the degree of 

 thickening, but not the pattern, of the cell walls. 



The genus is found primarily in elevated regions of the tropics but there is 

 one species in Patagonia and several others in the Northern Hemisphere. 



Key to the Species 



1. Plants of southern Chile and Patagonia. 11. 27. runcinatn. 



1. Plants of tropical, subtropical, or warm-temperate Latin America. 

 2. Leaves and underleaves more than twice as long as wide. 



3. Segments of the leaves and underleaves coarsely to faintly serrate 6. 27. serrata. 

 3. Segments of the leaves and underleaves entire (rarely with an occasional small 

 tooth). 



4. Segments ending in a long-acuminate tip. 



5. Cells of the tip and the upper part of the segment subquadrate. 5. 27. acanthtlia. 

 5. Cells of the tip and the upper part of the segment long rectangular. 



7. 27. Umbata. 



4. Segments of the leaves and underleaves acute, or acuminate by only two or 

 three cells. 



5. Vitta of the lamina bifurcate at about the middle; segments of the under- 

 leaves widely divergent. 3. 27. divergens. 

 5. Vitta of the lamina bifurcate just below the sinus; segments of the vn- 

 derleaves erect or a little divergent. 

 6. Segments long, linear, the vitta covering most of the width of the base, 



extending to the tip. 2. 27. pensilis, 



6. Segments lanceolate, the vitta covering about half the width of the base, 

 ending well below the apex. 

 7. Lamina at least twice as long as broad. 4. 27. grossispina. 



7. Lamina only a little longer than broad. 



8. Leaf -cells with thick, uneven walls ; plants of tropical areas. 



1. 27. jimiperoulra. 

 8. Leaf -cells with large, triradiate trigones and thin-walled pits; plants 



of southern South America. 11. 27. runcinata. 



2. Leaves and underleaves less than twice as long as broad. 

 3. Vitta of the lamina bifurcating near the base. 



4. Margins of the leaves and underleaves with a few sharp teeth ; leaf-cells with 



thick walls, the pits rarely visible. 8. 27. angustivittata. 



