18 Trans. Acad. Sci. of St. Louis. 



under the genus Ipomoea, shows conclusively that it is a 

 true Ipomoea. The large foliage and the inflorescence 

 somewhat suggests the genus Operculina, but the absence 

 of even the slightest tendency of the anthers to become 

 twisted after dehiscence and the loculicidal dehiscence 

 of the capule definitely exclude it from that genus. As an 

 Ipomoea, the plant falls in the section Batatas and sub- 

 section Aequise])alae of the above cited monograph. A 

 like comparison with the number of species thereunder 

 described shows it to be one not therein described. To 

 remove any possible doubt on this point com]5lete herb- 

 arium material and notes were submitted to Professor 

 House, who replied that he did not recognize the plant 

 as identical with any North American species known 

 to him. Later I had the pleasure of going over my notes 

 and the material in the Missouri Botanical Garden herb- 

 arium with Dr. Hallier, of Berlin, and he identified thi.-f 

 species, not as one of Ipomoea, as he recognizes the genus, 

 but of Merremia. Merremia is characterized by five 

 strong dark lines or veins running parallel through the 

 five longitudinal bands of the corolla — representing the 

 midveins of the cohering petals. Furthermore, the an- 

 thers of Merremia, after dehiscing, twist spirally around 

 on their longitudinal axes. The latter character is en- 

 tirel> absent in our specimen and the former can scarcely 

 be recognized. It seems, therefore^ in my judgment, cer- 

 tainly to belong to the genus Ipomoea as recognized by 

 Professor House. 



The following description was drawn from the living 

 plant as it appeared in the latter part of October and 

 early November, 1908, 



Ipomoea graudidentata n. sp. 



Stout perennial twining plant. Stem 15 m. long, from several long 

 very fleshy roots. Main stem light brown, roughened by raised len- 

 ticels, 1.3 cm. in diameter, ligneous, freely branching; branches green, 

 tinted with purple where exposed to the sun, early roughed by the 

 raised lenticels, otherv;ise glabrous; whole plant glabrous throughout: 

 internodes 10-15 cm. long. Leaves cordate-ovate in outline, base rather 



