Leaf epidermal characteristics of melons in the family Cucurbitaceae Juss. in Nigeria

In recent times, there has been a lot of adulteration, substitution of a certain plant parts for another among the melon species in the Cucurbitaceae family as a result of similarities of plant parts, due to the fact that these species are highly nutritious and medicinal and therefore well sought after by medical practitioners and students. Hence, study on the epidermal features of these plants was undertaken for easy identification. Five species of Cucurbitaceae, commonly called melons:  Citrullus lanatus Thunb. Matsum and Nakai (watermelon – three varieties based on the skin colour viz. light green (A), deep green (B) and striped green (C), Citrullus Colocynthis (L.) Schrad. (Egusi melon), Cucumis melo L. (sweet melon), Cucumis sativus L. (Cucumber), Cucumeropsis mannii Naud. (Syn. C. edulis (Hooker f.) cogn;  (White-seeded melon), and Cucurbita moschata (Duch. Ex Lam.) Duch. Ex Poiret) (Musk melon), found in Nigeria were studied. Epidermal features in the species included anomocytic and anisocytic stomata, glandular multicellular, and peltate trichomes and other epidermal features. The epidermal cell shape is irregular with sinuous anticlinal walls in C. colocynthis, trapezoid with straight anticlinal walls in two varieties of C. lanatus, C. sativus and C. mannii, and irregular with straight anticlinal walls in C. melo, C. moschata, and a varietry of C. lanatus. Stomatal index (SI) value are distinct for each species (9.01 in egusi melon and 5.30 in a variety of watermelon), being the highest and lowest in the Cucurbits studied. The study aims at improving taxonomic information on and the classification of these species. This study has successfully provided additional taxonomic characters in lieu of leaf epidermal features for the purpose of checking adulteration, substitution, and fraud carried out on these species.