“Out-of-India” dispersal for Adina (tribe Naucleeae; family Rubiaceae): evidence from the early Eocene fossil record from India

Abstract

This study reports the oldest fossil record of the genus Adina, A. vastanenesis n. sp., from the early Eocene of Vastan lignite mine (Cambay Shale Formation), Surat district, Gujarat. This fossil wood is characterized by diffuse porous wood, predominantly solitary tylosed vessels, simple perforations, scanty paratracheal to diffuse to sometimes diffuse in aggregate axial parenchyma, predominantly uniseriate to occasionally biseriate rays, and non septate fibres with bordered pits and shows its best resemblance with the modern species, Adina multifolia Haviland, belonging to the tribe Naucleeae (subfamily Cinchonoideae) of the family Rubiaceae. The present discovery becomes the first fossil record of the wood of Adina, which provides an insight about the Gondwanan origin either for the genus Adina or the tribe Naucleeae and its further dispersal to Southeast Asia.