Evans : Hepatjcae of Puerto Rico 21 



Pycnolejeunea Schwaneckei (Steph.) Schiffn. 



Lejeunea macroloba laxior Hampe & Gottsche, Linnaea 25: 356. 



1852. Not Lejeunea macroloba Mont 1843. 

 Lejeunea {Pycnolejeunea) Schwaneckei Steph. Hedwigia 27: 289. 

 pi. ij,f. 28. 1888. 



Pycnolejeunea Schwaneckei Schiffn. Bot. Jahrb. 23: 594. 1897. 



Glaucous-green, becoming brownish with age, growing in 

 loose depressed mats, often in company with other hepatics ; stems 

 0.17 mm. in diameter, prostrate and loosely adherent to the sub- 

 stratum, irregularly pinnate, an occasional branch long, unlimited 

 in growth and with normal leaves but most of the branches very 

 short, microphyllous, and concealed by the leaves of the higher 

 axis, all of the branches obliquely to widely spreading : leaves 

 more or less densely imbricated, the lobe convex and often revolute 

 at the apex, broadly falcate-ovate, 0.85-1 mm. long, 0.7-0.85 

 mm. wide, antical margin straight or slightly incurved near the 

 base, then strongly outwardly curved to the apex, arching partially 

 or wholly across the axis, postical margin revolute and curved, 

 apex broad and rounded, whole margin slightly and indistinctly 

 crenulate from projecting cells; lobule narrowly ovoid-cylindrical, 

 0.5 mm. long, 0.12 mm. wide (0.17 mm. wide when explanate), 

 inflated throughout, keel straight or nearly so, roughened from 

 projecting cells, free margin straight or nearly so, involute nearly 

 or quite to the apex, sinus lunulate, apical tooth blunt or subacute, 

 not curved, papilla in a scarcely evident depression ; cells of lobe 

 convex on both free surfaces, averaging 15 fi at the margin, 22 ft 

 in the middle and 28 fi at the base, walls thickened, especially the 

 antical wall, trigones large, triradiate, sometimes confluent or sepa- 

 rated by very narrow pits, intermediate thickenings occasional, cir- 

 cular in outline ; ocelli mostly four to nine, scattered but mostly 

 confined to the postical half of lobe and covered over by the pre- 

 ceding leaf, averaging 46 x 35 p - underleaves imbricated, broadly 

 orbicular, 0.35 mm. long, 0.4 mm. wide, broadly cuneate ^t the 

 base and sometimes bearing a rudimentary disc in the radicellif- 

 erous region, bifid one fifth to one third with erect divisions, 

 obtuse to subacute at the apex, and a narrow sinus ; cells and 

 margin as in the leaves : inflorescence dioicous : 9 inflorescence 

 borne on a leading branch, innovating on one side or more rarely 

 on both sides, the innovations sterile or again floriferous ; bracts 

 obliquely spreading, complicate, the lobe falcate-ovate, convex, 1.2 

 mm. long, 0.85 mm. wide, apex broad, margin as in the leaves, 

 keel narrowly winged, lobule ovate to obovate, rounded to sub- 

 acute at the apex, 0.75 mm. long, C.35 mm. wide; bracteole 



