Studies in the Family Rannnculaceae — Microsporangium, Microsporogenesis and TJbisch Granules in Nigella damascena

TLDR: The genus Nigella is unique in exhibiting connation of carpels and an involucre of much dissected leaves beneath each flower, which prompted the present investigation on Nigella damascena L.

Abstract: Introduction In the order Banales, Ranunculaceae are the largest family comprising about 49 genera and about 500 species. The family is characterised for its remarkable combination of primitive and advanced characters viz. actinomorphic or zygomorphic flower; free or fused carpels; multiovulate follicles or uniovulate achenes; crassior tenuinucellar ovules which may be ategmic, unitegmic or bitegmic; persistent or ephemeral antipodal cells and occurrence of mono, bi, and tetrasporic embryo sac development. The genus Nigella is unique in exhibiting connation of carpels and an involucre of much dissected leaves beneath each flower. Although many taxa of this family have been investigated from the point of comparative embryology, information on Nigella is meagre. This is particularly so with regard to the microsporangium, microsporogenesis and male gametophyte. This prompted us to take up this present investigation on Nigella damascena L. We are grateful to Professor B. M. JOHRI for encouragement and Dr. K. M. M. DAKSHINI for valuable suggestions.