Cambial variant in stems of Ipomoea (Convolvulaceae) native from Argentine.

Abstract

Cambial variant in stems of Ipomoea (Convolvulaceae) native from Argentine. Ipomoea is a diverse and complex genus, composed of herbaceous plants, woody lianas and vines, and a small group of shrubs and trees. It is noteworthy that all species studied previously presented different types of cambial variant in their stems, regardless of habit, except two taxa that showed normal secondary growth, a vine and a tree. Therefore, in this paper we study three vines natives from Argentina, Ipomoea cairica, I. purpurea and I. rubriflora, and I. carnea ssp. fistulosa, a tree with normal growth, in order to compare the development of their stems and provide useful information to elucidate their phylogenetic relationships.

The four species studied showed the same ontogeny and anatomy of their stems with primary growth, which would support its narrow phylogenetic relationships. On the other hand, the vines had only two

types of cambial variant, the lobed pattern and supernumerary cambium. We can infer that the type of secondary growth and cambial variant types would not be directly related to the habit; however, other
wood features can be considered as the proportion of parenchymal tissue and characteristics of the vessels.