Convolvulaceae of Indiana 273 



THE CONVOLVULACEAE OF INDIANA. 



Truman G. Yuncker, DePauw University. 



The family Convolvulaceae is represented in Indiana by the genera 

 Quamoclit, Ipomoea, Convolvulus and Cuscuta. The eight species of 

 Cuscuta known to occur in our State have been discussed by the writer 

 in recent papers^ presented to this Academy. It is proposed, in the 

 present paper, to present the species of the other three genera occurring 

 in Indiana and indicate their distribution and prevalence. Eleven species 

 may be recognized, one in the genus Quamoclit, four in the genus 

 Ipomoea, and six in the genus Convolvulus. All of these eleven species 

 present fairly definite and constant characters by which they may be 

 identified, with the possible exception of Convolvulus sepium and its close 

 relative C. fraterniflorus. A study of a larger number of collections of 

 these two species gathered over a wider range may show the inadvisa- 

 bility of maintaining them as separate species. Most of the species show 

 considerable variation in the shape of the leaves. In Ipomoea lacunosa, 

 for example, one may discover leaves of two or three distinctly different 

 shapes even on the same plant. Sketches are presented showing this 

 variation in leaf form and size in the different species. 



All of the specimens that could be obtained were studied and com- 

 pared. Mr. C. C. Beam's extensive collection was generously placed at 

 the writer's disposal and provided the largest number of specimens. All 

 collections are listed and the county in which they were obtained is 

 indicated. No collections or localities are included where the specimens 

 were not seen by the writer. 



KEY. 



Corolla tubular, not expanded at the 

 base, limb salverform; stamens and 

 style exserted; flowers not subtended 



by bracts 1. Quamoclit coccinea. 



Corolla mostly funnelform, stamens and 

 styles not exserted 

 Stigmas 2 or 3, grouped into a 



rounded, frequently papillate, .• . 

 knob; flowers not subtended by 



bracts (Genus Ipomoea) . 



Stems, petioles and peduncles re- 

 trorsely hairy 

 Sepals mostly long, attenuate- 

 caudate, tips spreading 2. Ipomoea hederacea. 



Sepals ovate-oblong to lanceolate. 3. Ipomoea purpurea. 



^ Notes on our Indiana dodders. Proc. Ind. Acad. Sci. for 1919. pp. 157-163. 

 A Species of Cuscuta not hitherto reported from Indiana. Proc. Ind. Acad. Sci. 

 for 1920. p. 229. 



'•Pi'oc. 38th Meeting. 1922 (1923)." 

 18—25870 



