1921] NATURAL SCIENCES OF PHILADELPHIA. 475 



6. MACUILLAMIA Raflnesque. 

 Macuillamia Raf., Autik. Bot. 44. 1840. 



Type species, Monniera rotundifolia Michx. 



1. Macuillamia rotundifolia (Michx.) Raf. 



Monniera rotundifolia Michx., Fl. Bor. Am. 2: 22. 1803. Hab. in regione 

 Illinoensi [A. IMichaux]." Type not verified, but description sufficiently 

 distinctive. 



Macuillamia rotundifolia (Michx.) Raf., 1. c. 44. 1840. 



Ranapalus rotundifolius (Michx.) Pennell, in Proc. Acad. Nat. Sci. Phila. 71: 

 242. 1920. 



Corolla with tube yellow within, the lobes white. Flowering 

 from June to October, and soon ripening fruit. 



Aquatic in shallow mud-bottomed open ponds, through the 

 upland of central Oklahoma and northern Texas, south to Travis 

 County; also in bottom-lands of the Coastal Plain, Ranges from 

 Indiana and Tennessee to North Dakota, eastern Colorado and 

 central Texas. 



Arkansas. St. Francis: Mud Lake, McAtee 1851 (U). 



Oklahoma. Washington: Copan, Stevens 2082 (U). 



Louisiana. Rapid3s: Alexandria, Hale (L, U, Y). 



Texas. Dallas: Dallas, Reverchon (Y). Matagorda: Bay City, 

 Fisher 166 (U). Randall: Paloduro Canyon,— (T). Tarrant: 

 Polytechnic, Ruth 579 (Y). Travis: Austin, Tharp (T). 



7. HYDRANTHELroM Humboldt, Bonpland. and Kunth. 

 Hydranthelium H. B. K., Nov. Gen. et Sp. 7: 202. 1825. 

 Type species, H. callitrichoides H. B. K., of Venezuela. 



1. Hydranthelium egense Poepp. 



Hydranthelium egense Poepp., Nov. Gen. et Sp. 3: 75. t. 287. 1845. "Crescit 

 in paludibus ad Ega in Brasilia boreah, Octobre lectum [Eduardus Poeppig 

 in 1827-32]." 



There can be no doubt of the identity of the Louisiana aquatic 

 with this species of Brazil. The exceedingly small flowers of this 

 genus and the occurrence of the plants in river-sloughs, cause them 

 to be little observed, and the species may be widely distributed 

 through Tropical America. H. egense has likely been brought to 

 Louisiana by bird-migrants. 



Aquatic in sloughs in central Louisiana. Probably introduced 

 from South America. 



Louisiana. Rapides: Alexandria, Hale (Y). 



8. STEMODIA Linne. 

 Stemodia L., Syst. Nat. ed. X. 1118. 1759. 

 Type species, *S. maritima L., of Jamaica. 



