Structure, distribution and taxonomic significance of leaf and petiole anatomical characters in five species of Terminalia (L.) (Combretaceae: Magnoliopsida)

Abstract

This paper presents a synthesis of a comparative leaf anatomy (lamina and petiole) of five species of the genus Terminalia found in southwest Nigeria. Collections of plants were made from different locations in Southwest Nigeria as the geographic locations of the sites of collection were also geo-referenced with a GPS device. The samples were identified at the Herbarium of Botany Department, Obafemi Awolowo University (Ife), Nigeria, and were subjected to anatomical examinations. Quantitative data were subjected to statistical analysis and the characters vary significantly (P = 0.05). Anatomical characters which separate the taxa include petiole outline, epidermal features, vascular pattern, occurence of cortical and pericyclic fibres, presence/absence of, and types of trichomes etc, all found to be useful in identification of different species. The variations in the anatomical traits could be effectively used in taxonomic delimitation of the species and are helpful characters in determining the complexes in the genus such as adaptation of the species to xeric environments. The presence of 2-3 layers of palisade mesophyll cells in Terminalia mantaly, which is an adaptation of the species to drought, is diagnostic for the species. It is suggested that a comprehensive consideration of leaf lamina and petiole anatomy should be used as basis of taxonomy.

Anatomical Studies on the Genus Terminalia L. (Combretaceae) in Egypt I- Leaf Structure

“…The structure of the petiole is significant for the discrimination of taxa and has considerable taxonomic importance in many genera, once it is less affected by environmental changes (Metcalfe & Chalk, 1950); the shape and type of vascular cylinder in the petiole were remarkable characters (Ayensu, 1968) as the morphologic separation is hard within some species (Leme & Scremin-Dias, 2014). Particularly, Akinsulire et al (2018) utilized the shape of the vascular cylinder and the arrangement of the accessory vascular bundles of the petiole as diagnostic characters for the separation between five species of Terminalia in southwest Nigeria. He placed T. mantaly and T. catapa in one group based on their quantitative leaf anatomical characters.…”

“…In this work, anatomical characters were the basis to separate the taxa, including petiole and leaf outline, epidermal feature, vascular pattern, the occurrence of cortical and pericycle fibers, presence / absence of crystals and trichomes in addition to the shape of main vascular bundle and number of accessory vascular bundles. Terminology of the anatomical characters of leaf and petiole was described according to Metcalfe & Chalk (1950), Tilney (2002) and Akinsulire et al (2018).…”

“…In the recent past years, the leaf anatomical characters in the genus Terminalia (lamina and petiole) have been studied by many authors (Tilney, 2002;Ingle & Dhabe, 2011Akinsulire et al, 2018) for the identification of the relationships between its species.…”

“…The main vascular bundle in the leaf was of diagnostic characters, it takes an open-heart shape in T. brownii (Plate 2; G & H) and a crescent shape in T. mantaly(Plate 3; M & N) Akinsulire et al (2018). described the vascular bundle of T. mantaly as deeply crescent form or lunar-shaped Seema et al (2015).…”

Struktur Anatomi Daun Sebagai Bukti Dalam Pembatasan Takson Tumbuhan Berbunga: Studi Kasus 12 Suku Tumbuhan Berbunga Indonesia

“…Pengamatan secara transversal menunjukkan bahwa semua jenis yang diamati memiliki epidermis atas dan epidermis bawah daun yang terdiri atas satu lapis sel (uniseriate). Beberapa penelitian juga menunjukkan bahwa jumlah lapisan epidermis dapat digunakan sebagai ciri taksonomi pada tingkat marga (Devecchi et al 2014;Lin & Tan 2015;Akinsulire et al 2018), sedangkan epidermis ganda (multiple epidermis) ditemukan pada Rhizoporaceae (Stace 1965) dan Pandanaceae (Rahayu et al 2011).…”