﻿The rediscovery of Caryapoilanei (Juglandaceae) after 63 years reveals a new record from China.

Wei-Ping Zhang,Da-Yong Zhang,Wei-Ning Bai

doi:10.3897/phytokeys.188.77242

Abstract

Despite having been first published in 1941, Caryapoilanei (A.Chev.) J.-F.Leroy is only known from three collections in Vietnam, Laos and Thailand. It has not been recollected since then and was long suspected to have become extinct through repeated deforestation events. Here, we report the rediscovery, and meanwhile the first new record in China, of this extremely rare gigantic hickory species at Yunnan province 63 years after its last collection in 1958. Three small patchy subpopulations were found with a total of about 50 adult trees having diameter at breast height (DBH) larger than 60 cm, together with some seedlings and saplings, but the fruit set was low. Based on new and fresh material, we present a revised morphological description of C.poilanei, and an updated distribution map for the species. In addition, we also provide a key for the hickories in China. Lastly, we suggest C.poilanei should be listed as a Critically Endangered (CR) species according to the latest IUCN Red List Categories and Criteria.

Highlights

French botanist Auguste Chevalier placed C. poilanei into the genus Juglans after he observed the only specimen collected from Vietnam in 1941 (Chevalier 1941)
The possible reason is that C. poilanei has the lacunae character (Fig. 3Q-R) which superficially resembles some species in the genus Juglans
The presence of lacunae in the septum and/or shell walls are an atypical characteristic of relict hickory species, it has been recorded in seven fossil species from

Summary

Introduction

Carya Nutt., consisting of ca. 17 currently accepted species (Manning 1978; Chang and Lu 1979; Lu et al 1999; Zhang et al 2013; Grauke et al 2016), is the second largest genus in Juglandaceae DC. ex Perleb after Juglans L. (Kozlowski et al 2018), with a discontinuous distribution in South-Eastern Asia and eastern North America. Five hickory species have been recognized in South-Eastern Asia, in southern China, northern Vietnam, northern Laos, northern Thailand and north-eastern India (Manning 1963; Chang and Lu 1979; Srisanga 2017). Carya tonkinensis Lecomte seems to be the most widespread species in South-Eastern Asia, distributed in southwest China, northern Vietnam, northern Thailand and north-eastern India (Manning 1963; Chang and Lu 1979; Srisanga 2017). It would be conducive to inferring its phylogenetic position within Carya, and valuable to exploit its genetic resources for breeding and crop development in future days

Materials and methods

Discussion