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. | Turk J Bot (2013) 37: 847-858 © TÜBİTAK doi: Turkish Journal of Botany Research Article A further analysis of secretory structures of some taxa belonging to the genus Hypericum (Clusiaceae) in relation to the leaf vascular pattern 1 1 2 1, Rosaria PERRONE , Paolo DE ROSA , Olga DE CASTRO , Paolo COLOMBO * Department of Earth and Marine Sciences, Division of Ecology, University of Palermo, Palermo, Italy 2 Department of Biology, University of Naples Federico II, Naples, Italy 1 Received: Accepted: Published Online: Printed: 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. Key words: Hypericum, leaf vascular pattern, black nodules, secretory canals, translucent glands 1. Introduction Hypericum L. is a genus of the family Clusiaceae, belonging to the subfamily Hypericoideae (Cronquist, 1981). It includes more than 460 species that are spread throughout the world, and many are well .
