FOUR NEW PLANTS FROM MEXICO.* 



Chaeles Henry Thompson. 



A Yellow Flowered Morning- Glory. 



In the fall of 1906 the Missouri Botanical Garden re- 

 ceived from Mr. Rudolph Holtzwart, of St. Louis, two 

 seeds of a morning-glory, part of a number sent him from 

 Torreon, Mexico. In the latter part of August, 1910, the 

 writer had opportunity to see the plant from which these 

 seeds were taken. It was growing as a cultivated plant 

 and trained up over a two-story house and over a tall 

 tree. Near its base the stem was about 8 cm. in diameter, 

 freely branching above, some of the branches reaching a 

 length of several hundred meters. The Garden succeeded 

 in growing one plant from the seed received, and this 

 flowered abundantly in its second season of growth. The 

 first year the vine attained a length of about 4 m. and 

 formed a tuber-like root-crown about 3 cm. in diameter 

 in the middle, and 15 cm. long, subtended by a number 

 of fleshy roots, the size of a lead pencil, and smaller. The 

 stem was frozen to the ground after which the root was 

 transplanted in the greenhouse, in open soil, where it 

 remained till January, 1909. 



As the plant flowered and fruited it was carefully com- 

 pared with extensive herbarium material, as well as de- 

 scriptions of all the species of I porno ea published, in an 

 unsuccessful attempt to identify it. Careful study has 

 been made with reference to Professor House's espe- 

 cially good monograph^ of the genus. A comparison of 

 our plant with the different genera, as recognized by 

 Professor House, which have previously been assembled 



* Presented by title before The Academy of Science of St. Louis, 

 February 20, 1911. 

 ' House, H. D. Annals N. Y. Acad. Sci. 18 : 181-263, 11 May, 1908. 



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