A further analysis of secretory structures of some taxa belonging to the genus Hypericum (Clusiaceae) in relation to the leaf vascular pattern

Abstract

This work extends knowledge about the distribution of secretory structures (black nodules, translucent glands, and type A and B secretory canals) to other species of the genus Hypericum L., as only H. perforatum L. appears to have been widely investigated. Moreover, the current study was extended to include leaf vascular patterns. In the species studied, a possible correlation between the presence of black nodules and a particular biological form, that of hemicryptophytes scapose perennials such as H. perfoliatum L., H. perforatum L., H. pubescens Boiss., H. tetrapterum Fr., and H. triquetrifolium Turra, was noted. These black nodules are not present in H. androsaemum L. and H. hircinum L., which are bushy nanophanerophytes, or in H. aegypticum L., a xero-halophyte. The xylem pattern results are camptodromous brochidodromous in H. androsaemum, H. hircinum, H. perforatum, and H. pubescens; basal acrodromous in H. perfoliatum, H. tetrapterum, and H. triquetrifolium; and camptodromous cladodromous in H. aegypticum.