

Igor] ERIOCAULON DECANGULARE 19 
the results. Furthermore, some notes upon the anatomy of the 
leaf and stem are appended, for it must be remembered that very 
little has been published heretofore upon the anatomy of Erio- 
caulon. As stated above, the root structure has been discussed 
by Van Tieghem, but only in reference to seven species of the 
genus ; and &. helichrysoides is the only one which ts treated from 
a general histological point of view by V. A. Poulsen in his ana- 
tomical study of the order. Besides these papers there are 
some few scattered remarks upon the structure of various organs 
of the genus in the works of DeBary, Russow, and Schwendener. 
There is thus only one paper in which a general anatomical 
treatment of the order has been presented, the work by Poulsen 
cited above. This author, who has studied fifteen species belong- 
ing to nine genera, especially Paepalanthus, all from Brazil, 
deserves credit for having detected several structural peculiari- 
ties; and it is a matter for regret that but one species of the 
large genus Eriocaulon has been examined. 
In the present paper some of the anatomical features of &. 
decangulare will be discussed, and attention will be called to such 
points as do not harmonize with the conclusions of Poulsen and 
Van Tieghem in reference to this species and others. The 
material was collected in sphagnum swamps in the vicinity of 
Washington, D. C. These swamps are wet during the entire 
season, so that the plants which were studied were not exposed 
to any drought during the summer months; furthermore, the 
plants were almost fully exposed to sunlight. Among the 
plants associated with Eriocaulon may be mentioned: Furena 
squarrosa, Scleria reticulata, Eleocharis tuberculosa, Rhynchospora alba, 
R. glomerata, R. cephalantha, Xyris flexuosa, Pogonia ophioglos- 
soides, Drosera rotundifolia, Utricularia subulata, Rhexia Mariana, 
and Asclepias rubra. 
THE ROOT. 
The roots of &. decangulare studied were all secondary, being 
developed from the rhizome. Two kinds may be distinguished : 
some that are quite thick, white, mostly unbranched, and with 
5 Anatomiske Studier over Eriocaulaceerne. Thesis, Copenhagen. 1888. 
