Asplenium nidus L. commonly called as Bird’s Nest Fern, is a threatened, ornamental fern, which is widely used as novel foliage ornamental plant and local people use it in worship. The taxon is threatened due to over exploitation, habitat destruction and genetic barriers. To understand the constraints in the regeneration, reproductive biology studies are made. It is observed that more sporophytes are produced in composite population (13.3%) in comparison to isolate population (10%). This pattern is suggestive of the fact that the parental sporophyte is heterozygous for recessive sporophytic lethal. On the basis of the results obtained A. nidus was initially adapted for outbreeding with the capacity for considerable amount of inbreeding. The low potential of sporophyte production in isolate gametophyte could be the constitution of the zygotic genotype.
 E. J. Klekowski Jr., “Reproductive Biology of the Pteridophyta III. A Study of the Blechnaceae,” Botanical Journal of Linnean Society, Vol. 62, 1969, pp. 153-169. doi:10.1111/j.1095-8339.1969.tb01973.x
 E. J. Klekowski Jr., “Reproductive Biology of the Pteridophyta II. Theoretical Considerations,” Botanical Journal of Linnean Society, Vol. 62, 1969, pp. 347-359. doi:10.1111/j.1095-8339.1969.tb01972.x
 F. R. Ganders, “Heterozygosity for Recessive Lethals in Homosporous Fern Populations: Thelypteris palustris and Onoclea sensibilis,” Botanical Journal of Linnean Society, Vol. 65, No. 2, 1972, pp. 211-221. doi:10.1111/j.1095-8339.1972.tb00934.x
 E. A. Hooper and A. H. Haufler, “Genetic Diversity and Breeding System in a Group of Neotropical Epiphytic Ferns (Pleopeltis; Polypodiaceae),” American Journal of Botany, Vol. 84, No. 12, 1997, pp. 1664-1674. doi:10.2307/2446464
 M. S. Lott, J. C. Volin, R. W. Pemberton and D. F. Austin, “The Reproductive Biology of the Invasive Ferns Lygodium microphyllum and L. japonicum (Schizaeaceae): Implications for Invasive Potential,” American Journal of Botany, Vol. 90, No. 8, 2003, pp. 1144-1152. doi:10.3732/ajb.90.8.1144
 P. B. Khare, S. K. Behera, S. Ruchi and S. P. Shukla, “Studies on Reproductive Biology of a Threatened Tree Fern, Cyathea spinulosa Wall. ex Hook,” Current Science, Vol. 89, No. 1, 2005, pp. 173-177.
 R. Srivastava, J. Srivastava, S. K. Behera and P. B. Khare, “In-Vitro Studies on Development of Gametophyte, Sex- Ontogeny and Reproductive Biology of a Threatened Fern, Microsorium punctatum (L.) Copel,” Indian Journal of Biotechnology, Vol. 7, 2008, pp. 266-269.
 R. Srivastava and P. B. Khare, “Development of Gametophyte and Reproductive Biology of a Homosporous Fern; Coniogramma indica from Kumaon Himalaya,” In: M. Singh and A. K. Paliwal, Eds., Advancement of Science and Technology, 2010, pp. 582-588.