Evans: A new Lejeunea" 527 



Britton cf Marble 1251, 1254, 1255; on stones, Crown, February, 

 1913, Britton & Marble 1365. 



No. 1365 from St. Thomas may be designated the type; a 

 slight admixture of L. pililoba Spruce is present. 



In the genus Lejeunea the lobule when typically developed 

 consists of an inflated sac, ovate in outline, more or less involute 

 along the free margin, and tipped by a single projecting cell with a 

 hyaline papilla at its proximal base. The same general type of 

 lobule is found in several other genera of the Lejeuneae, such as 

 Rectolejeunea, Ceratolejeunea, and Crossotolejeunea. Unfortu- 

 nately, in certain species of Lejeunea, the lobule often fails to show 

 its typical structure and appears reduced in size or otherwise 

 variously modified. In some cases a prolonged search may be 

 necessary before inflated lobules can be demonstrated at all, and 

 it is not unusual for poorly developed lobules to be associated with 

 plants bearing perianths. In the species here proposed as new no 

 inflated lobules whatever have been seen, although many plants, 

 both with and without perianths, have been examined. The 

 lobule in all cases observed has been in the form of a minute basal 

 fold, consisting of only a few cells. It seems safe to assume, 

 therefore, that lobules of this reduced type represent a constant 

 feature of the species. 



With respect to size, the leaves, perichaetial bracts and per- 

 ianths of L. miniUiloha exhibit a considerable range of variation, 

 and on slender stems and branches the leaves may be scarcely 

 half as large as on robust stems. The small bracts and perianths 

 are associated especially with short female branches, the size 

 varying approximately with the length of the branch. The small- 

 est bracts and perianths, therefore, are usually to be found on 

 branches which bear a single vegetative leaf in addition to the 

 bracts. The underleaves and bracteoles are much less subject 

 to variation in size than the leaves and bracts ; they vary markedly, 

 however, in the character of their apices. These are sometimes 

 acute- or even apiculate, sometimes obtuse, and sometimes broadly 

 rounded. 



Among related species it will be sufificient to mention L. 

 fioridana Evans and L. glaucescens Gottsche. The first is still 

 known from Florida only, but the second is widely distributed in 



