6 Evans : Hepaticae of Puerto Rico 



Cheilolejeunea decidua (Spruce) Evans 



Lejennea {Cheilo-Lejeuned) decidua Spruce, Hep. Amaz. et And. 



257. 1884. 

 Cheilolejeunea decidua Evans, Bull. Torrey Club 32 : 1 88. 1 905. 



* 



Pale- or brownish-green, growing in depressed mats : stems o. 1 2 

 mm. in diameter, copiously and irregularly branched, the branches 

 obliquely to widely spreading, prostrate or ascending, sometimes 

 like the stem but often with smaller and deciduous leaves ; 

 rhizoids present on the prostrate axes, few or wanting on the 

 ascending branches : leaves (when well developed) imbricated, the 

 lobe plane or slightly convex, obliquely spreading, ovate, 0.7 mm. 

 long, 0.4 mm. wide, attached by an almost longitudinal line of in- 

 sertion, antical margin arching across or just beyond the axis, 

 strongly curved to apex, postical margin straight or nearly so, 

 apex broad and rounded, margin entire ; lobule triangular-ovate in 

 outline, 0.17 mm. long, 0.12 mm. wide, keel slightly arched or 

 almost straight, free margin straight or nearly so, apical tooth 

 long, pointed and slightly curved, appressed to the lobe and 

 forming part of the opening into the water-sac ; cells of lobe 

 plane, averaging 1 2 p. at the margin, 2 1 /i in the middle and 

 30 x 23 fi at the base, sometimes thin-walled throughout, but 

 usually with small triradiate trigones and occasional intermediate 

 thickenings: underleaves distant, plane, orbicular, 0.2 mm. long, 

 often cuneate toward the base, bifid one third to one half, with 

 broad, triangular, erect, acute, subacute or apiculate divisions sep- 

 arated by a broad and obtuse sinus ; margin entire or sinuate : in- 

 florescence dioicous : 9 inflorescence borne on a short and usually 

 simple branch, rarely with an innovation on one side ; bracts ob- 

 liquely spreading, more or less complicate, the lobe oblong to obo- 

 vate, 0.65 mm. long, 0.4 mm. wide, subfalcate, rounded at the 

 apex, entire, lobule linear, 0.3 mm. long, 0.1 mm. wide, acute to 

 rounded at the apex ; bracteole free, obovate, 0.5 mm. long, 0.35 

 mm. wide, bifid about one sixth with obtuse to acute lobes and 

 sinus, margin entire ; perianth broadly obovate in outline, 0.6-0.75 

 mm. long, 0.5 mm. wide, strongly compressed, antical face plane 

 or slightly concave, lateral keels sharp, postical keel low and 

 broad, rounded or bluntly two-angled, apex rounded to slightly 

 retuse, with a short but distinct beak : $ inflorescence occupying a 

 short branch or terminal on a longer branch ; bracts in one to three 

 pairs, subimbricated, strongly inflated, shortly and subequally bifid 

 with rounded divisions, keel strongly arched ; antheridia borne 

 singly or in pairs : mature sporophyte not seen : vegetative repro- 

 duction by means of leafy propagula growing from the leaf-cells 



(PLATE I, FIGURES I -9). 



