LEAFY HEFATICAE OF LATIN AMERICA — FART I 



65 



6. Segments of the leaves and underleaves divergent; leaves bifid to one-half 



of their length ; plants small, red to reddish-green. 1. 7. tenax. 



6. Segments of the leaves and underleaves erect or only slightly spreading; 

 median leaf cells thin-walled. 

 7. Underleaf margins incised-toothed with several long, coarse teeth; 



median leaf -cells averaging 58 X 25 fi. 9. I. grossidens. 



7. Underleaf margins with shorter teeth. 



8. Plants small, compact, dark brown to greenish-brown ; median leaf 



cells averaging 47 X 16 m- U. !• fragilis. 



8. Plants larger, pale green to greenish-brown ; leaf-cells 60-90 X 20-30 fi. 



4. J. madida. 



Underleaves smaller and shorter than the leaves. 

 3. Underleaves usually with one very large tooth on one or both sides, rarely with- 

 out teeth. 



4. Lateral tooth of the underleaf as large as the segment ; leaf segments one-half 

 to one-third the length of the leaf, broadly triangular; median leaf-cells 

 long, thin-walled; plants large, flaccid, green. 13. I. obtusiloba. 



4. Lateral tooth of the underleaf smaller than the segment; leaf sinus usually 

 broad, lunulate; plants of small to medium size, often reddish to reddish- 

 brown. 



5. Leaves tending to be canaliculate, spreading to reflexed ; median leaf-cells 



averaging 45 X 23 /*. 2. I. multiceps. 



5. Leaves and underleaves closely imbricate; median leaf -cells averaging 



80 X 30 /i. 3. 7. crythrorhiza. 



3. Underleaves with several teeth on the lateral margins. 



4. Leaf margins with a single row of somewhat enlarged cells, the long axis 



at a right angle to the margin ; leaf sinus V-shaped to lunulate. 10. I. influta. 

 4. Leaf margins without a row of enlarged cells. 

 5. Underleaf segments and the lateral teeth long. 



6. Underleaves more or less quadrate, bifid to one-half of their length ; 



teeth of the margins long, coarse; plants brownish-green. 9. I. grossidens. 

 6. Underleaves rounded to orbicular or subrectangular, bifid to less than 

 one-half of their length, the marginal teeth long, slender. 

 7. Underleaves orbicular, the segments as such not conspicuous. 7. I. auberti. 

 7. Underleaves orbicular to subrectangular. 



8. Segments long, narrow, blunt, the sinus narrow, U-shaped; marginal 



teeth slender. 6. I. haematodes. 



8. Segments shorter, the sinus broad, U-shaped, marginal teeth broad, 



triangular. 5. I. serrulate 



5. Underleaf segments and the lateral margins sparsely to abundantly 

 dentate, denticulate, serrulate by a single cell, or ciliate-dentate ; under- 

 leaves oval, orbicular, ovate-truncate, or subrectangular. 

 6. Median leaf -cells averaging 47 X 16 m; plants small, compact, dark 



brown to greenish. 11. I. fragilis. 



6. Median leaf -cells more than 50 /* long ; plants larger. 

 7. Segments of the underleaves broadly triangular. 



8. Cells of the median portion of the leaf without intermediate thick- 

 enings in the walls ; plants greenish to greenish-brown. 

 9. Leaf sinus broad, tending to be lunulate; leaf margin with one 



or two teeth. 10. I. inflata. 



9. Leaf sinus narrow, V-shaped; leaf margin with three to five 



teeth. 4. 7. madida. 



8. Cells of the median portion of the leaf with conspicuous intermediate 

 thickenings in the cell walls. 

 9. Intermediate thickenings and trigones conspicuous, distinct, large, 



in the segments knot-like. 5. 7. serrulata. 



9. Intermediate thickenings and trigones more or less coalesced into 



an uneven layer of secondary thickening. 6. 7. haematodes. 



7. Segments of the underleaves narrow-triangular to ligulate, the apex 

 broad. 



8. Underleaf margin, including the sinus, appearing to be scalloped 

 and serrulate to denticulate, the teeth mostly one-celled, usually 

 icd-tipped. 8. 7. lindigiana. 



