Abstract
Seedling and stomata types in variously aged seedlings of Sesbania bispinosa (Jacq.) W.F. Wight are described. The seedling, according to Garwood’s (1996) scheme of seedling classification, was Phanerocotylar-epigeal- foliaceous type – cotyledons enclosed in seed coat are raised above the soil due to rapidly growing hypocotyl and later the cotyledons coming out of seed coat and undergoing expansion. After Vogel (1980) seedlings of Sesbania bispinosa may be referred to as Macaranga type (Macaranga hispida). There appeared a greater degree of stomatal diversity in S. bispinosa – relatively higher diversity in cotyledons than in the leaves. In all, the seedlings exhibited the occurrence of anisocytic, anisotricytic, anomocytic, tetracytic, staurocytic, and infrequently the paracytic types of stomata. There were a few desmocytic stomata on the epicotylar stem only. Abnormal stomata included the stomata with common subsidiary (ies), contiguous stomata (placed juxtaposed or the two stomata placed more or less at right angle) and deformed stoma with more than one pores and stoma with no guard cells. Totipotency of guard cell was noticed in a cotyledonary stoma - division to give rise a new cell. The hypocotyl and dorsal and ventral surfaces of three-day old cotyledons of S. bispinosa had epidermal cells with straight or curvy anticlinal walls but 7-day old cotyledons showed curvy to sinuous anticlinal walls. Leaves exhibited curvy to sinuous anticlinal walls. Undulations were U-shaped. On primary simple leaf of the seedling, waviness of the epidermal cells averaged to 6.34 ± 0.206 wave crests per cell varying from 3 to 10 (CV = 27.24%). The number of undulations per cell was larger in larger cells. At least in case of cotyledons, the degree of waviness appeared to be influenced by the age of the cotyledons as undulations in the contour of epidermal pavement cells were only observed in 7-day old mature cotyledons. Three-day old cotyledons exhibited no undulations in the pavement epidermal cells.
