Comparative foliar epidermal morphology of Isolona Engl. (Annonaceae)

Abstract

A qualitative micromorphological assessment of the seven species of Isolona occurring in Nigeria and the Cameroons was undertaken with the aid of light microscope. The stomatal cells are particularly useful, providing stable characters which can be reliably employed in distinguishing the species. Hypostomatic leaves and paracytic stomatal type are generic constant. Possession of only paracytic stomata is characteristic of I. dewevrei whereas other species may have in addition another type such as 1+2 laterocytic stomatal type found only in I. zenkeri and presence of brachyparacytic stomata which shows relatedness of I. campanulata, I. congolana, I. hexaloba, I. pleurocarpus and I. thonneri. The epidermal surfaces appeared glabrous but an indication of hairs is shown by the presence of a glandular trichome base only in I. hexaloba. The epidermal cell characters such as epidermal cell shapes and anticlinal wall patterns seem to intergrade and they are not as definite as the stomatal cells. However, a combination of these features will be helpful in defining the species better and their leaf fragments can be differentiated based on the various characters studied for effective utilization in herbal medicinal research.

Leaf epidermal characteristics of Annonaceae Juss. and its taxonomic evidence in Nigeria and the Cameroons

“…The taxonomic usefulness of gross morphology, foliar epidermis, and gross leaf anatomy has been well reported on tropical plant species and used to resolve several taxonomic intricacies (Adeniran et al, 2020; Davis & Heywood, 1963; Ogundipe & Kadiri, 2012; Sonibare et al, 2004). These characters have been previously used to support the recognition of the species and the identification of several taxa as well.…”

“…Leaf epidermal preparations were carried out using herbarium and dried un‐mounted plants collected during biodiversity studies. One to five centimeters square portions were cut from the standard median portion of the leaf lamina near the mid‐rib or the whole leaf following the approaches of Ogundipe and Olatunji (1991), Olowokudejo (1993), Ayodele (2000), Kadiri (2003), Adeniran et al (2020). Leaves were hydrated by boiling in water and soaked in concentrated trioxonitrate(v) acid (HNO 3 ) in glass bottles for about 8–24 h to macerate the mesophyll or irrigated in sodium hypochlorite solution (commercial bleach) for 30 min to 2 h to bleach the leaf portions of recalcitrant species.…”

“…In the UPGMA tree, subclusters A, D, E, and H were sufficiently separated from the other species to form the subfamily Annonoideae, whereas the remaining subclusters: B, C, F, G, and I could not be clearly separated into either the tribal or subfamily rank within the family (Figure 6). The taxonomic usefulness of gross morphology, foliar epidermis, and gross leaf anatomy has been well reported on tropical plant species and used to resolve several taxonomic intricacies (Adeniran et al, 2020;Davis & Heywood, 1963;Ogundipe & Kadiri, 2012;Sonibare et al, 2004). These characters have been previously used to support the recognition of the species and the identification of several taxa as well.…”

“…Leaf epidermal characters aid the interrelationships of taxa at and above the species level. The taxonomic usefulness of gross morphology, foliar epidermis, lamina architecture, and gross leaf anatomy has been well reported on tropical plant species and has been used to resolve several taxonomic intricacies (Adeniran et al, 2020; Adeyemi & Ogundipe, 2012; Ogundipe & Kadiri, 2012; Sonibare et al, 2004).…”

“…on tropical plant species and has been used to resolve several taxonomic intricacies (Adeniran et al, 2020;Adeyemi & Ogundipe, 2012;Ogundipe & Kadiri, 2012;Sonibare et al, 2004).…”