1968] 



LEAFY HEPATICAE OF LATIN AMERICA PART III 



335 



6-12 cells in diam, the cortical layer of many rows of cells usually little different from 

 the cells of the medulla. Rhizoids from cells along the ventral side of the stem. 

 Line of leaf insertion oblique, sometimes nearly longitudinal, the leaves succubous. 

 Leaves orbicular to ovate, undivided or rarely emarginate, the margin plane or 

 upcurved, the cells uniformly thin-walled or with small or large trigones separated 

 by thin-walled pits, the marginal cells sometimes different and forming a border. 

 Underleaves scale-like, few-celled. Plants dioicous. Male inflorescence a bud- or 

 catkin-like ventral branch. Female inflorescence on a short ventral branch, the 

 bracts in 3 or 4 series, bifid. Perianth long, 3-keeled above, the mouth contracted, 

 the 3 lobes crenulate, setulose or short or long ciliate. Capsule oval, brown, the wall 

 of 2 layers of cells with characteristic markings. Gemmae 2-celled, thin-walled, 

 green or red, borne at the tips of small-leaved erect shoots. 

 Type: Jungermannia sphagni Dickson, 1785. 



Key to the Species 



1. Leaf cells with small or tiny trigones with concave sides. 



2. Leaves narrow-rectangular, plane, the marginal leaf cells 15-20 p; plants whitish. 



4. 0. soratamum. 



2. Leaves broad-rectangular to long-orbicular; plants light green, yellow-brown or 

 reddish. 



3. Leaves plane, the marginal cells IS X IS ix, with thicker walls than the rest. 



1. 0. longiflorum. 



3. Leaves concave, with an upturned margin of 1-3 rows of cells. 



4. Leafy stems arising singly from the rhizome; marginal leaf cells 13-20 /x, with 



uniformly thickened walls. 2. 0. prostratum. 



4. Leafy stems arising in tufts from a leafless stolon ; marginal leaf-cells mostly 



20 X 20 ix. 3. O. stoloniferum. 



1. Leaf cells with large, rounded or knot-like trigones. 



2. Plants tiny, deep red or purple, often curved; leaves rounded, trigones very large. 



10. O. atropurpureum. 



2. Plants larger, the leaves mostly longer than broad; green, yellow-brown or tinged 

 with red. 



3. Leaves plane; marginal cells large, rectangular with a thick outer wall; upper leaf 

 cells to 26 ix or larger; trigones very large. 



4. Leaf margin undulate and crisped. see Anomoclada. p. 346 



4. Leaf margin straight. 9. O. falcifolium. 



3. Leaves concave with a more or less upturned margin. 



4. Cells of the border large, 26-30 /x, the outer wall very thick, the cell lumina 



angular. 8. O. brasiliense. 



4. Cells of the border mostly less than 20 n, the walls thickened, the trigones 



conspicuous. 



S. Leaves broad ovate-cordate, the dorsal part recurved. 7. O. cordifolium. 



S. Leaves ovate to orbicular, the leaf not folded. 



6. Cells of the upper part of the leaf mostly 20-24 ix in diam ; trigones 



large, the cell cavities stellate 6. O. denudatum. 



6. Cells of the upper part of the leaf larger, 26-30 fx in diam; the trigones 



knot-like, separated by thin cell walls. S. O. variabile. 



1. Odontoschisma longiflorum (Taylor) Stephani, Spec. Hep. 3: 370. 1908. 



Sphagnoecetis longiflora Taylor, London Jour. Bot. 5: 281. 1846. 



Odontoschisma sphagni var. Spruce, Rev. Bryol. 15: 33. 1888. [Glaziou no. 7231.] 



Odontoschisma planifolium Stephani, Spec. Hep. 3: 370. 1908. 



Odontoschisma glaziovii Stephani, Spec. Hep. 3: 372. 1908. [Glaziou no. 7231.] 



Plants light or pale green, rarely tinged with red near the tips, prostrate, occa- 

 sionally becoming erect, small-leaved and gemmiparous, in mats or among other 

 bryophytes; stems 1-2 cm long, with leaves to 2 mm wide, more or less frequently 



