19661 



LEAFY HEPATICAE OF LATIN AMERICA — PART II 



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4. Leaves and underleaves acute to acuminate, usually widely spreading. 



4. M. grandistipulum. 

 4. Leaves acute, the apices often decurved; underleaves rounded to ovate- 

 truncate; leaf margins entire. 3. M. tatei. 

 1. Leafy stems clearly dorsi-ventral, often flattened; underleaves only to one-half 

 the size of the leaves or smaller, rarely absent. 

 2. Leaf cells plane or scarcely convex on the outer surface; cuticle smooth, faintly 

 to coarsely verruculose or warty. 

 3. Underleaves conspicuous, as broad or broader than the stem, scarcely decreasing 

 in size to the tip of the stem. 

 4. Underleaves rounded, broader than the stem; leaves not conspicuously keeled; 

 leaf margins undivided, crenulate by projecting cell walls; cells 10-13 ix. 



17. M. conchijolium. 



4. Underleaves longer than broad or if rounded, the apex conspicuously divided. 

 5. Leaves ovate-truncate to rectangular, keeled above but not conspicuously 

 folded, the margins and wing incised- toothed ; underleaves to twice as long 

 as broad. 8. M. leiophyllum. 



5. Leaves folded or sharply keeled throughout their length. 



6. Leaf apex acute, the wing small, developed only in the upper part, or 

 longer, the margins distantly serrate, and dentate; leaf cells 12-16 (ii. 



7. M. rcimersianum. 

 6. Leaf apex blunt, rounded, the wing broad, the margins entire; leaf cells 



15-18 ft. 10. M. lechleri. 



3. Underleaves becoming smaller or absent toward the tip of the stem. 

 4. Margins of the leaf and wing entire or nearly so; leaves more or less equally 

 folded. 



5. Underleaves quadrate, not broader than the stem. 5. M. carinatum. 



5. Underleaves usually of only a few cells; cells of the leaves and underleaves 

 with large trigones with bulging sides; cell cavities angular rounded. 

 6. Cell surface covered with large, round to ellipsoidal warts. (Venezuela.) 



18. M. tumidulum. 



6. Cell surface verruculose. (Dominica, Cuba.) 6. M. exalatum. 



4. Margins of the leaf and wing variously serrate, dentate and incised ; the keel 

 sharp, the wing long and broad, the ventral lobe small; leaf cells 15-20 (i. 



9. M. pterygophyllum. 

 2. Leaf cells strongly convex, or with a single large mamillose projection conspicuous 

 on the outer wall of most cells; cuticle smooth to verruculose or warty. 

 3. Leaves strongly concave, without a wing or with a wing of only a few cells 

 on some leaves; cell mamillae very large, often nearly as broad as the cells. 



11. M. bolivarense. 

 3. Leaves with one, or a pair, of well-developed wings along the keel. 



4. Leaves with a well-developed pair of wings extending from the apex to the 



middle or beyond. 15. M. bialatum. 



4. Leaves with a single unistratose wing extending from the apex to the middle 

 of the leaf or beyond. 

 5. Underleaves large, conspicuous, present throughout the stem. 

 6. Leaves small, the margins entire, the wing only in the upper part; 



cells 10-12 p. 12. M. campanense. 



6. Leaves small to large, the margins serrate, dentate and incised, the wing 



conspicuous, long; cells 15-20 13. M . trachyphyllum. 



5. Underleaves decreasing in size to the tip of the stem, often obscure. 



6. Stems tiny, leaves short, concave, the wing small or rudimentary just 



below the apex (or absent). 11. M. bolivarense. 



6. Stems larger, leaves complanate, elongate, the wing extending to the 



middle or below. 14. M. parvistipulum. 



1. Micropterygium surinamense (Steph.) Reimers, Hedwigia 73: 145. /. 1. 

 1933. 



Lembidium surinamense Stephani, Spec. Hep. 6: 445. 1924; Icon. Hep., Lembidium No. 6. 



