Taxonomical Identity of ＂Rhizophora＂ × ＂annamalayana＂ Kathir and ＂Rhizophora＂ × ＂lamarckii＂ Montrouz (Rhizophoraceae) in the Andaman and Nicobar Islands, India

P. Ragavan ； R.S.C. Jayaraj ； Alok Saxena ； P.M. Mohan ； K. Ravichandran

《TAIWANIA》 60卷4期 (2015/12) Pp. 183-193

https://doi.org/10.6165/tai.2015.60.183

並列摘要

In India, ＂Rhizophora＂ hybrids have been recorded in Pichavaram (Tamil Nadu) and in the Andaman and Nicobar Islands (ANI). ＂Rhizophora＂ hybrids in Pichavaram mangrove forest were identified as ＂Rhizophora＂ × ＂annamalayana＂, a cross between ＂R. apiculata＂ and ＂R. mucronata＂, whereas ＂Rhizophora＂ hybrids in the ANI were identified as ＂Rhizophora＂ × ＂lamarckii＂, a cross between ＂R. apiculata＂ and ＂R. stylosa＂. However taxonomical distinction between them was not much explored. A recent floristic survey revealed the occurrence both ＂R. × annamalayana＂ and ＂R. × lamarckii＂ in the ANI, India. Based on critical analysis of specimens and morphometric analysis, it was found that both ＂R. × lamarckii＂ and ＂R. × annamalayana＂ can be distinguished from ＂R. apiculata＂ by their smooth green bract and bracteoles and 2-4 flowered inflorescences within the leaf axils. ＂Rhizophora＂ × ＂annamalayana＂ is distinguished from ＂R. × lamarckii by its broader leaves (length: width ratio ＜ 1.8 vs ＞ 1.8), and shorter style (＜1.5 mm vs. ＞ 1.5 mm) and stamens in two whorls vs. usually in a single whorl. ＂Rhizophora＂ × ＂annamalayana＂ is the new record from the ANI. Higher relative density of ＂R. × annamalayana＂ than ＂R. × lamarckii＂ in the ANI is attributed to the abundance of its parental species (＂R. apiculata＂ and ＂R. mucronata＂) in the ANI.

並列關鍵字

Andaman and Nicobar Islands ； India ； Mangroves ； ＂Rhizophora＂ ； hybrids ； ＂R. × annamalayana＂ ； ＂R. × lamarckii＂