Morphological and Anatomical Studies on Ipomoea coccinea L. (Convolvulaceae): A New Record from Nigeria

Abstract

We reported the morpho-anatomy of Ipomoea coccinea L. a new record from Nigeria for the first time. Fresh plant materials (stem, petiole, and leaf) were fixed immediately in Formalin-Acetic-Alcohol for 24h, dehydrated, embedded in paraffin wax sectioned using rotary microtome, Sections were stained with Safranin and counterstained with Alcian blue and micro-photographed with trinocular research microscope fitted with Amscope digital camera. Ipomoea coccinea is twisting climber with reddish flowers; vine is up to 10 m long with alternate leaf arrangement. The leaf is amphistomatic and dorsiventral. The epidermal cells are irregular in shape with wavy anticlinal walls. The upper epidermis has only paracytic stomata while the lower epidermal surface has mainly paracytic stomata but rarely anisocytic measuring 4.36–8.7×3.9–6.24 µm. The stomata on the upper epidermis are few and mainly located close to the leaf veins. The vascular bundle in the petiole formed a semi-circle with one rib trace. The abaxial and adaxial parenchymatous cortex comprised 7–11 layer of cells with crushed parenchymatous cells below the epidermal cells. The midrib outline is circular to U-shaped with long median projection measuring about 80–90 µm. The stem has protuberances, short glandular trichome, cortex 6–8 layers, and rays in radial multiples of 3 – 6, a continuous thick layer of xylem, and a discontinuous ring of sclerenchymatous fibre. It has glandular peltate trichome with 5 – 6 basal cells which occurred mainly on the lower surface of the leaves but partly on the stem and upper leaf surfaces. The laticifer is found in the cortical parenchyma of the petiole, midrib, and stem while the papillose is found on the stem and the midrib. The calcium oxalate (druses) sparsely occurred in the phloem tissues in the stem. These features of the species confirm that it is member of the Convolvulaceae family.