A PRELIMINARY STUDY OF THE GENUS 
LAMPROSPORA 
Fred J. Seaver 
(With Plate 114, Containing 13 Figures) 
In a previous paper , 1 the writer has called attention to some 
of the difficulties in the study of the present genus and in the 
same paper described two new species. The accumulation of ad- 
ditional data regarding the various species of the genus together 
with the collection of several apparently undescribed species has 
led the writer to make a preliminary study of the genus in North 
America. One of the most conspicuous features of many of the 
plants of the genus is their small size, many of them being one 
millimeter or less in diameter. For this reason many of the 
species have apparently been overlooked and even the best known 
are not often collected. While the ground has been covered as 
thoroughly as possible at the present time, it is not likely that 
the following list contains nearly all of the species occurring in 
North America. 
About half of the species of the genus have sculptured spores 
and the nature of the sculpturing in such species furnishes one of 
the most valuable diagnostic characters. In many of the old 
descriptions the spores were simply described as rough or smooth 
with no definite information as to the exact nature of these 
roughenings. In the present paper especial attention has been 
given to a study of these spore characters. In most cases these 
studies have been based on fresh material collected by the writer. 
In a few cases we have been compelled to rely on dried specimens. 
An attempt has been made to bring out these characters in the 
accompanying plate. 
The genus as treated here is used in rather a broader sense 
than the genus Barlaea of Saccardo, being made to include the 
genus Detonia, which, so far as I am able to judge, differs only in 
1 MyCOLOGIA 4: 45-48. I9|2. 
5 
