CHARACEA AMERICAN. 3 
Ch. erstediana, A.Br. (a gymnopus), it is as long as the other internodes. This 
latter variety also presents naked terminal internodes which we find not infrequent, 
in var. elegans; the same is true of Ch. Angolensis, A.Br. Ch. Commersonti, A.Br. 
(Kiitzing, Tab. Phyc. 78) has a shorter basal node but naked terminal internodes. 
So the variations are very great and devoid of any morphological character 
like that which determines the gymopod@. Indeed, even in this we find evidence 
of transition: Ch. fragilis and its allies differ from Cz. gymnopus only in the cortication 
of the basal node of the leaf; but in Cz. brachypus A.Br., the triple series of cortex 
cells which cover the basal node are imperfectly developed, devoid of chlorophyll 
and almost colorless. 
Lexplanation of Plate \. 
A. Plant natural size. 
’ B. Verticill magnified 20 diameters ; 1, main stem with series of cortex cells, three 
series to one leaf (only a portion of the 12 leaves of the verticill shown) and long spines ; 
2, stipules in a double series, one erect the other deflexed upon the stem; 3. the 
naked basal node of the leaf. 
C. A leaf magnified 20 diameters with a naked basal internode, 8 corticated 
internodes and a terminal naked internode; 1, one of the two stipules ; 2, bracts 
longer than sporangium or node, developed all around the leaf; 3, cortex cells, 
in a triple series, divided as usual in the middle of the internode, the upper 
half developed downward from the node above, the lower half developed upward 
from the node below; 4, the sporangium with black, oval nucleus and spreading 
coronula of five, pointed cells (In this well fruited specimen, a sporangium but no 
antheridium, was developed on the first node); 5, the antheridium occupying the place of 
a bract and bearing the sporangium in its axil. 
