1968] 



LEAFY HEPATICAE OF LATIN AMERICA — PART III 



359 



Plants larger; leaf cephalozoid, of many cells, bifid with triangular segments; under- 



leaves mostly 4 cells wide. 1. R. serrus. 



1. Regredicaulis serrus (Spruce) Fulford, comb. nov. 



Cephalozia Subg. V Eucephalozia, serra Spruce, On Cephalozia 32. 1882. 



Zoopsidella serra (Spruce) Schuster, Nova Hedwigia 10: 30, 41. 1965. Non rite public. 



Alobiella serra Schuster, Nova Hedwigia 10: 29. 196S. Non rite public. 



Plants small, pale green, in mats or among other bryophytes; stems turgid, 1-2 

 cm long, robust stems with leaves to 0.5 mm wide, irregularly branched; branches 

 ventral-intercalary in the axils of underleaves, either very slender flagelliform with 

 3 rows of cortical cells and 2 or 3 rows of 1 -celled leaves; or the stems larger, with 

 2 rows of dorsal cortical cells between the two rows of 1- or 2-celled leaves and a 

 row of underleaves, suggesting R. monodactylus; or thicker, stolon-like with 3 rows 

 or tufts of rhizoids, or semi-flagelliform with small leaves or leaves with one segment; 

 or thick, flagelliform soon becoming leafy; stem showing 2 dorsal rows of large 

 cortical cells between the 2 rows of leaves, in transverse section somewhat flattened, 

 with a cortical layer of 6 large cortical cells (2 + 2 lateral, 2 ventral), and a medulla 

 of 5 or 6 small cells. Rhizoids long or short, bulbous at the tip, from small cells 

 of the base of the underleaves and from the base of the female inflorescence. Line 

 of leaf insertion oblique, the leaves rarely becoming sublongitudinal. Leaves distant 

 to approximate, spreading, ovate-quadrate, bifid to one-third their length or rarely 

 retuse, crenulate, the segments straight, triangular from a 2- or 3-celled base; cells 

 of the base of the segment 26-35 X 26-35 fi, the walls uniformly thickened, the 

 cuticle verruculose. Underleaves reduced to a row of 2-4 cells across the stem, 

 rarely 2 rows, a cell sometimes dividing to form a rhizoid initial. Plants dioicous. 

 Male inflorescence on the stem or a leafy branch, long catkin-like, the bracts and 

 bracteoles in 10 to many series, the bracts bifid, like the leaves, smaller, monandrous, 

 the bracteoles like the underleaves. Female inflorescence on a short leafy ventral 

 branch, the bracts and bracteoles in three series, the inner series the largest, the bracts 

 bifid, the segments long triangular, acuminate. Perianth long, cylindrical below, 3- 

 keeled above, the mouth of 6 long acuminate, often ciliate, laciniae. Sporophyte 

 capsule dark brown, ovoid. 



PI. 95. Fig. 1, a-n. 



Habitat: On wood in humid forest. 



BRAZIL: Silva Amazonica: Fl. Uaupes, Spruce, Hep. Sprue, (type MANCH, isotypes BM, 

 G, NY) ; cataracts, Rio Negro, Spruce, Hep. Sprue. (MANCH) ; S. Gabriel et Panure, Spruce, 

 Hep. Sprue. (G-13418, NY). 



2. Regredicaulis monodactylus (Spruce) Fulford, comb. nov. 



Cephalozia Subg. Ill Zoopsis, monodactyla Spruce, On Cephalozia 28. 1882. 

 Zoopsis monodactyla (Spruce) Stephani, Spec. Hep. 3: 282. 1908. 



Arachniopsis Subg. Monodactylopsis, monodactyla (Spruce) Schuster, Nova Hedwigia 10: 30. 

 196S. 



Plants tiny, confervoid, whitish-green, in small patches or among other bryo- 

 phytes. Stems 0.5-1 cm long, somewhat flattened, with 2 rows of cortical cells 

 between the opposite rows of leaves, in transverse sections of 3-4 rows of cortical 

 cells (1 + 1 lateral, 1 ventral), and one or a few medullary cells; branches frequent, 

 ventral-intercalary, axillary, leafy or flagelliform, or short with male and female 

 inflorescences. Rhizoids few, from small cells of the bases of the underleaves. Leaves 

 patent, of a single cell, rarely 2, the cell inflated-ovoid to cylindrical, capped with a 



