SPHENOCLEA ZEYLANICA AND CAPERONIA PALUSTRIS 
IN THE SOUTHERN UNITED STATES. 
By Ivar TIDESTROM. 
SPHENOCLEA ZEYLANICA. 
In 1903, a plant was sent to the United States Department of 
Agriculture for determination from Gueydan, Louisiana, with the 
intimation that it was a threatening weed in rice fields. It proved 
to be Sphenoclea zeylanica Gaert. and since then has been reported 
from time to time. 
This species was described under its native name, ‘pongati,” 
and also iliustrated by Rheede! as early as 1692 and the illustration 
alone is almost sufficient for the identification of the plant. Adanson * 
mentions it under this vernacular name, citing at the same time the 
figure by Rheede. In 1788, Gaertner 3 diagnosed the genus and gave 
a description of the only species under the name here accepted. 
The illustration by Gaertner shows a pentamerous flower and an 
ovary with 2 cells and a central placenta. The vernacular name 
“tembulwaenna” is also given. Jussieu‘ characterized the genus 
the following year under the name ‘ ‘Pongatium.” This author cites 
Rheede’s figure. He places the genus among Plantae incertae sedis 
and in addition to the generic diagnosis he observes as follows: 
“ Herba aquatica (Rheede Mal. II. t. 24); folia alterna; flores dense spicati terminales; 
horum tubus staminifer mox deciduus. Caracter ex sicco. Habitus Phytolaccae 
junioris. An affinis Samolo p. 97, aut Portulaceis?”’ 
In 1790, Loureiro® diagnosed the genus Rapinia and described 
one species, R. herbacea, which has been referred by nearly all the 
great authors to Sphenoclea zeylanica. Loureiro evidently referred 
the bract and two bractlets which subtend the flowers to the calyx, 
hence his diagnosis of the calyx: ‘“Perianthium 8-partitum, inferum: 
laciniis subrotundis, concavis: bino ordine, exteriori breviore.”” In 
all other respects the account given of Rapinia agrees well with the 
characters of Sphenoclea. Loureiro appears to have been the first 
to notice the flowers, for he placed the plant in the class Pentandria 
and in the order Monogynia of Linneus’s simple, provisional, but very 
excellent method for determining plants. 
In 1791, Retzius® described the plant under the name Gaertnera 
pangati. He distinguished the subtending bracts, which he describes 
1 Hort. Malabar. 11: 47. pl. 24. 4Gen. Pl. 423. 1789. 
2 Hist. Nat. Sénég. 83. 1757. 5 Fl, Cochinch. 1: 127. 1790. 
8 Fruct. & Sem. 1: 118. pl. 24. f. 5. ® Obs. Bot. 6: 24. 1791. 305 
