36 



feet, with occasional ridges of slightly higher elevation, down to 

 sea level in the southernmost portion. The appearance of this re- 

 gion is, on the whole, that of a flat treeless prairie, though along 

 the water courses it is wooded. Geologically, these prairies are a 

 part of the coastal plan that extends from New England south- 

 ward to the Gulf of Mexico, and along the southern border of the 

 United States westward as far as the indenture made by the Gulf. 

 A conspicuous feature of these prairies is the numerous sand 

 mounds that have given this region the name of ''pimpled 

 prairies." These mounds exist more or less over the entire area 

 and generally upon the more elevated parts of the area are found 

 two to fifteen rods apart. In such localities they have an average 

 height of perhaps tw^o feet and a diameter of from fifteen to fifty 

 feet. Everywhere these mounds appear as little domes. Occasion- 

 ally, in the marsh areas, none of these mounds appear^ but in 

 other marsh areas they are more abundant. Furtherinore, in 

 certain marsh areas the mounds are both more abundant and 

 larger than elsewhere. The origin of these mounds seems to be 

 somewhat uncertain ; from a botanical point of view, they show 

 no distinction from the surrounding country. At present, rice is 

 about the only crop grown in this region, though it is possible 

 that with proper cultivation many other crops might give profit- 

 able returns. The few disjointed botanical notes which follow are 

 to be considered as merely preliminary to a detailed study of this 

 most interesting region. This the writer hopes to carry out shortly 

 after another season of collecting spent in this locality. 



Sphenoclea Zeylanica Gaertn. 



(Pongatmm Indicnm, [Juss] Lam.) On entering the rice 

 region of Calcasieu, this plant immediately attracts the observer 

 by its abundance. It covers many acres on the borders of the rice 

 fields, almost to the exclusion of any other plant. Some few miles 

 south of Lake Charles the writer drove seven miles along a 

 country road completely choked up by it. It is not mentioned by 

 Chapman, Small, or Wood, but it has been known to be abun- 

 dant in Louisiana for over sixty years. It was first reported in 

 1840 by Dr. Hale. It is described in Gray's Synoptical Flora of 

 North America, Volume II, Part I, Page 10, who says that it is 

 a native of tropical Africa or Asia, naturalized in Louisiana. 



