One of several morphological characters widely used in the separation of species and varieties in the genus Viola is that of lamina pubescence. In some cases, particularly in the common acaulescent* blue violets, specific distinctions based primarily on leaf pubescence have proven unsatisfactory. In other instances in Viola, presence or absence of pubescence has served as an excellent separating character between certain closely allied species. In his comprehensive survey of hybridism in the violets, Brainerd (1924) often used the amount of pubescence as an indication of degree of hybridization and demonstrated in many cases that it was inherited apparently in Mendelian fashion. However, his results seem to indicate, on re-examination, that pubescence is inherited in a "quantitative" fashion. Amount of lumina pubescence apparently depends in most cases on several or many alleles. Only rarely in the genus have the actual nature of the pubescence and its distribution on the leaf been observed or described. In certain of the white violets, to be discussed below, position and type of pubescence are important diagnostic characters, and both are almost certainly inherited.
*"Acaulescent" is defined here as meaning plants with the stem almost completely below the surface of the soil.
Proceedings of the Iowa Academy of Science
©1954 Iowa Academy of Science, Inc.
Russell, Norman H.
"Variation in Leaf Pubescence in Viola incognita Brainerd and V. renifolia Gray,"
Proceedings of the Iowa Academy of Science, 61(1), 151-160.
Available at: https://scholarworks.uni.edu/pias/vol61/iss1/18