Phenology, seed germination and some vegetative features of Strobilanthes fragrans (Acanthaceae), a recently described unusual species, found only in a single Forest Park in Thailand

Abstract

Strobilanthes fragrans is a rare and endangered plant which occurs only in Tam Pet Tam Tong Forest Park (Chonduea mountain), in Nakon Sawan province. The present study fills in gaps in the knowledge of this species, since it was described on the basis of limited material in 2009. It has a plietesial flowering cycle and during the past 11 years it has flowered synchronously throughout all populations only twice, at an interval of 7 years. Flowering occurs when plants have shed all their leaves and after seed production all plants die, demonstrating they are monocarpic. A new cycle begins with germination of the seeds. Its prop roots, characteristic internodal/nodal regions and a possible bee pollinator are described and illustrated. Seeds germinate readily without pre-treatment and do not undergo dormancy.