Introgressive Hybridization in a Natural Population of Tradescantia.

ETAILED analyses of populations containing natural hybrids have D been reported recently. ANDERSON (1936) has suggested a method for expressing quantitatively the extent of hybridity of a population and for comparing various populations, and this method has been applied to various genera such as Tradescantia (ANDERSON 1936) , Solidago (GOODWIN 1937), and Iris (RILEY 1938, 1939) The present paper reports a morphological and cytological study of a population of Tradescantia growing along a railroad right-of-way about fifteen miles east of the center of New Orleans, Louisiana. This population was more complex than most of the populations of that genus reported by ANDERSON and HUBRICHT (1938) for i t involved three species of which two were tetraploids and the third a diploid.