Species diversity of Rhizophora in Tambelan Islands, Natuna Sea, Indonesia

Research on diversity and distribution of mangroves on the small remote islands are rarely performed than on the coastal area and estuaries. Tambelan Islands is a cluster of small islands isolated in the Natuna Sea, Indonesia. On the island there are four species of Rhizophora, namely R. apiculata, R. stylosa, R. mucronata, and hybrid species R. x lamarckii. Rhizophora stylosa and R. apiculata are the most common species found. R. mucronata only found in certain places (i.e. Durian River), R. x lamarckii rare, usually grows in stands that also covered by the two parental, R. stylosa and R. apiculata. All Rhizophora species were found to have thorn on the leaf tip, and spotted brown on the underneath leaf. R. apiculata has a petal without woolly feathers, inflorescence have short stalks and cork. R. stylosa and R. mucronata are sibling species, both of them have a long-stalks and dichotomy inflorescence, but the style of R. mucronata very short (<2.5 mm), whereas in R. stylosa longer (> 2.5 mm). R. x lamarckii has characters between R. apiculata and R. stylosa.