Marotandrano Special Reserve is located south of the town of Marotandrano, 4 km south of Mandritsara. The main rivers which rise in the area are the Amboaboa, Andranokelilalina and Andramy, which flow to the Indian Ocean, and the Vatolahy and Mahatsara, which flow to the Mozambique Channel. The vegetation is mid-altitude, dense, humid evergreen forest, lying at the western limit of such habitat. Trees of Tambourissa, Dalbergia, Onchostemum and Canarium dominate the upper layer, while the mid-stratum is characterized by tree-ferns, bamboo-lianas and palms. On the ridges, the lower vegetation layer is dense and characterized by thick grass clumps.
See Box and Tables 2 and 3 for key species. Among the 76 recorded species, two are little known—Eutriorchis astur and Tyto soumagnei—and 49 are endemic to Madagascar.