[ 2 j 
CLASS I. MONANDRIA. 
ORDER II. DIGYNIA. 
1. Callitriche, X. Gen. PI. 17. (Najades.J 
Calix inferior, ’ 2-leaved. Corolla 0. Seeds 
4, naked, compressed. 
heteropbyiia. 1. C. Upper leaves spathulate-obovatc ; lower ones 
linear, obtuse, and emarginated \ occasionally all 
the leaves linear. 
C. verna. Willd. sp. pi. 1, p. 28. 
C. aquatica. Smith, FI. Brit. 
C. autumnalis. Willd. sp. pi. p. 29. 
C. linearis. Pursh, FI. Am.^Sep. vol. i. p. 3. 
A very varying plant, putting on at different seasons of the 
year, such amorphous appearances, that it has been described 
as distinct species by botanists, under the different synonyms 
above enumerated. Dr. James Edward Smith first noticed the 
identity of C. verna and C. autumnalis. I have adopted Pursh’s 
specific name, as it sufficiently expresses the variations in the 
leaves ; but his C. linearis is nothing more than one of the ca- 
pricious states of this singular plant. 
“ The leaves of the calix are described by Desfontaines as 
being concave, and lunate, with the filament as long as the ca- 
iix : in the American plant the stem is compressed, and bifistu- 
lous, for floating ; the lower branches with narrower and often 
emarginated leaves, producing only male or female flowers, 
the central branches with retuse, spathulate oval, S nerved 
leaves, bearing those which are hermaphrodite, with the sta- 
mens much exserted.^’ NuttalU 
In springs, rivulets, and brooks, where the water is clear— 
along the Schuylkill, in such places— on the bank- walk to the 
Woodlands most abundant — in Jersey along the course of the 
Delaware, and elsewhere. Annual. Flowers from May to 
July- 
