Obligate Apomixis in Zeuxine strateumatica (Lindl.) Schltr. (Orchidaceae)

Mode of embryo formation was studied in a population of Zeuxine strateumatica (Lindl.) Schltr. growing naturally at Dhanas (340 m), Chandigarh, India. The gynoecium was tricarpellary and syncarpous. The unilocular ovary possess 3 parietal placentae which developed ovule primordia. The hypodermal cell of ovule primordium got differentiated into an archesporial cell. Megaspore mother cell either developed directly into embryo through mitosis or got degenerated. In most of the ovules, 1–3 nucellar cells function as embryonal initial which subsequently form mature embryo. Presently studied population exhibited obligate apomixis, a type of asexual reproduction observed occasionally in some angiosperms.