Ascorbic Acid and Hip Fertility in Rosa Species

FOR the past few years we have been studying the genetical and other problems presented by a rose population growing on a pit heap in Co. Durham. Only two species, Rosa mollis var. typica and R . dumetorum var. ramealis , are involved; but, in addition, there is a unique hybrid between the two which, as it possesses a chromosome complement of thirty-five, has the parentage dumetorum ♀ × mollis ♂.