136 ALEXANDER W. EVANS 



In many species of Lejeunea the female branches vary greatly in 

 length. This is strikingly true in the case of L. minutiloba Evans, a 

 species of the West Indian lowlands, closely related to L. cladogyna. 

 A female branch in this species is sometimes greatly elongated and 

 sometimes so short that it bears a single vegetative leaf and a single 

 underleaf in addition to the bracts and bracteole. Between these two 

 extremes all intermediate conditions occur. In L. cladogyna the female 

 branches, so far as observed, are always very short and conform to the 

 second of the two extremes noted under L. minutiloba. It would 

 perhaps be premature to state that this condition is absolutely con- 

 stant, but it is certainly predominant, and it therefore seems justi- 

 fiable to regard it as one of the distinctive characters of the species. 



In size and in general habit L. cladogyna and L. minutiloba resemble 

 each other very closely, and the inflorescence in both species is autoi- 

 cous. In L. cladogyna, moreover, the lobule is usually reduced to a 

 minute basal fold. While, however, this condition seems to be con- 

 stant in L. minutiloba, inflated lobules of the usual Lejeunea type are 

 occasionally produced in L. cladogyna, although many plants seem to 

 lack them completely. The new species is further distinguished by 

 its underleaves, bracts and perianths. The underleaves, even, when 

 well developed, are only a little broader than the stem and the divi- 

 sions are rarely more than four cells wide at the base; the lobules of 

 the bracts are highly connate with the lobes and sometimes approxi- 

 mate them in length; the, perianth is rounded at the apex, and the 

 five keels extend to the middle or beyond. In L. minutiloba the 

 underleaves are often twice as broad as the stem and the divisions 

 may be six or more cells wide ; the lobules of the bracts are less highly 

 connate with the lobes and much shorter, appearing like small basal 

 appendages; the perianth is truncate or slightly retuse at the apex, 

 and the keels are restricted to the apical portion. 



In L. glaucescens Gottsche, another West Indian species found also 

 in Florida, the female branch seems to be constantly very short, just 

 as in L. cladogyna, and the two species agree further in their autoicous 

 inflorescence and in the fact that their lobules are often poorly de- 

 veloped. L. glaucescens, however, is a larger and more delicate species 

 than L. cladogyna and has larger leaf-cells, the median cells of the 

 lobes averaging about 33 m in length. It is further distinguished by 

 its sharper lobules and by the sharper divisions of its bracteoles. 



Two other species of Lejeunea, L.floridana Evans and L.flava (Sw.) 



