Abstract Detail

Systematics Section/ASPT

Tomaz, Eduardo [1], Gahagen, Benjamin [2], Ballard, Harvey [3].

Investigations of Petiole Anatomy and Leaf Epidermal Morphology of Tovomita (Clusiaceae).

Tovomita Aubl. (Clusiaceae) is a relatively small genus (approximately 45 species) of trees, shrubs, and hemi-epiphytes ranging from Central America to central South America. Many diagnostic macromorphological features are used to identify species of this genus, but some species are still uncertainly identified as Tovomita because of the lack of studies regarding them and the genus. Although micromorphology and anatomy are often left aside in taxonomic studies, traits gleaned from these perspectives can still be used along with macromorphology to compare different species and infer evolutionary relationships. This has been shown to be true in other genera related to Tovomita, but there is a lack of knowledge about this specific genus. This study aimed to analyze petiole vasculatory anatomy and epidermal leaf morphology in Tovomita species. Petioles and leaf samples were obtained from dried herbarium material. For petioles, a conventional microtomy technique was used, where samples were infiltrated and embedded in paraffin for sectioning. The sections were mounted on slides and observed in sequence in order to see the development of the leaf trace from the stem to the lamina. Leaf samples were incubated in a hot ethanol and hydrogen peroxide solution, and both adaxial and abaxial layers were separated and observed under a light microscope. The results present a significant variation between species, most specifically in stomatal type, subsidiary cells shape, and petiole vascular bundles. Stomatal shape varied from paracytic to more and less brachyparacytic. In addition, stomatal size and density were highly diverse between species. Some species were found to have subsidiary cells with lobed or entire margin, but an intermediary pattern was also observed. Remarkable differences in the petioles’ arc-shaped trace were evidenced, including the presence and absence of a medullary bundle. In an overall view, each analyzed species had a particular trait or shared it with one or a few species. Thus all the variations found can be combined with macromophological studies to refine species relationships within Tovomita.

1 - Ohio University, Environmental and Plant Biology Department, 317 Porter Hall, Athens, OH, 45701, USA
2 - Ohio University, 317 Porter Hall, Athens, OH, 45701, USA
3 - Ohio University, ENVIR & PLANT BIOLOGY-PORTER H, 315 Porter Hall, Athens, OH, 45701-2979, USA

Keywords:
Tovomita
anatomy
Petiole
epidermal.

Presentation Type: Poster:Posters for Sections
Session: P
Location: Eyrie/Boise Centre
Date: Monday, July 28th, 2014
Time: 5:30 PM
Number: PSY024
Abstract ID:567
Candidate for Awards:None