Arenga westerhoutii Griff. and Livistona jenkinsiana Griff., two new species of wild palms for Banglades

Abstract

INTRODUCTION The genus Arenga Labill and Livistona R. Br., are represented by one and two species in Bangladesh respectively (Siddiqui et al. 2007, Rahman 2018). In Bangladesh, these genera were known to contain the following three species: Arenga pinnata (Wurmb) Merr., Livistona chinensis (Jacq.) R.Br. ex Mart. and Livistona speciosa Kurz. (Siddiqui et al. 2007, Rahman 2018). Sangu-Matamuhuri Reserve Forest is one of the last strongholds of biodiversity in Bangladesh (Creative Conservation Alliance 2016). Sangu Reserve Forest (SRF hereafter) is located in the south of Boro Modok in Thanchi Upazila of Bandarban District, Bangladesh (Fig. 1). The actual floral diversity of SRF is still unknown. We conducted a field exploration at this remote forest during February 2019. SRF is a part of the Indo-Burma Biodiversity hot spot (Myers et al. 2000). SRF is the Sangu Wildlife Sanctuary (SWF), which was declared by the Forest Department of Bangladesh (Creative Conservation Alliance 2016). The climate of the region is tropical, with a mean annual rainfall of 2,666 mm. A dry and cool season occurs in that region from November to March, followed by a hot and sunny pre-monsoon season from April to May, and a warm, cloudy, and wet monsoon season from June to October (Khan 2015). During vegetation observation inside the forest, we found two species of unusual wild palms that are grown on hill slope sporadically associated with other vegetation and bearing fruits. Further, we reviewed the Siddiqui et al. (2007) and Rahman (2018) and confirmed these two palms are not reported from Bangladesh. Then the field photographs were sent to a palm specialist and finally examined as Arenga westerhoutii Griff. and Livistona jenkinsiana Griff. Hence, we reported these two species as new wild palms for Bangladesh. Direct observation has been done by a random walk inside the SRF (Fig. 1) and from the boat while moving in Sangu River. The field visit was from 20 th to 28 th February 2019. Clear photographs have taken for unknown plant species and also for the two unusual wild palms. We failed to collect any plant samples because they are grown on the top hills. Therefore, we took pictures with a telephoto lens. The photos are uploaded on a global database (inaturalist.org). The identification of these palms confirmed through field photographs that were examined by tropical Asian palm specialists.