To date, 242 plant species from 58 families and 158 genera have been documented on the Montagne des Francais, and the inventory is not finished. More than 40 percent of the species belong to just five plant families: Rubiaceae, Fabaceae, Malvaceae, Euphorbiaceae, and Sapindaceae. But the real treasures are the endemics. The baobab Adansonia suarezensis, distinguished by its shiny brown bark, grows only in this corner of northern Madagascar. The aloe Aloe suarezensis is similarly restricted to this area. The flame tree Delonix regia - familiar worldwide as an ornamental, with its canopy of scarlet blossoms - originated here. And then there is Baudouina solleyformis, a tree still used locally as traditional protection against witchcraft, its cultural significance intertwined with its botanical rarity.

Zoological surveys have identified 19 amphibian species, 52 reptiles, 56 birds, and 21 mammals on the mountain. Of the reptiles and amphibians, eight species are endemic to the Montagne des Francais alone - found on this single mountain and nowhere else on the planet. Another 28 are regional endemics restricted to northern Madagascar. Two species appear on the IUCN Red List as globally threatened, and 14 are listed under CITES international trade protections. The mountain receives more rainfall than the surrounding area - Antsiranana gets roughly 1,000 millimeters annually, but the mountain's elevation, ranging from 100 to 450 meters, wrings additional moisture from passing clouds. This explains the lush forest clinging to its slopes in an otherwise arid bioclimatic zone, creating a green island in a dry landscape.

The mountain's French name - Mountain of the French - traces to the colonial period, when France built military fortifications across its summit to defend Diego Suarez Bay. The ruins of Fort Anosiravo still stand at the top, along with the crumbling barracks of the fort's commander. These positions saw real combat during World War II, when British forces invaded Vichy French-held Madagascar in 1942 to prevent Japan from gaining access to the island's strategic harbor. The fighting around Diego Suarez and the surrounding heights was fierce - the Vichy defenders held out stubbornly before the port fell. Today, the trail to the summit takes about two hours from the paved road to Ramena, and hikers pass through the fortification ruins with their gun emplacements and observation points still oriented toward the bay, still watching for an enemy fleet that last appeared more than eighty years ago.

The main threats to the Montagne des Francais come from the city it overlooks. Antsiranana's demand for timber and charcoal drives logging on the mountain's forested slopes. Unlike most of Madagascar, where slash-and-burn agriculture is the primary cause of deforestation, the Montagne des Francais is spared that particular threat: its karst terrain is unsuitable for farming. But charcoal production strips the trees just the same. Conservation International has provided technical support and funding for reserve creation, working alongside local organizations and the regional government. The mountain is part of the larger Ramena protected area complex, which also includes the Orangea Reserve and the Ambodivahibe Marine Reserve. Whether these protections arrive in time for the last Diegodendron trees - a species known from only a few dozen individuals - remains an open question.