Gardens’ Bulletin Singapore 69(1): 33-65. 2017 
doi: 10.3850/S2010098116000039 
33 
Index of names and types of Hoya 
(Apocynaceae: Asclepiadoideae) of Borneo 
M. Rodda 
Herbarium, Singapore Botanic Gardens, National Parks Board, 
1 Cluny Road, Singapore 259569 
rodda.michele@gmail.com 
ABSTRACT. Types of all Hoya species occurring in Borneo and their synonyms are indicated 
and clarified. Forty-six lectotypes, nine neotypes and five epitypes are designated. 
Keywords . Brunei, epitype, holotype, Kalimantan, lectotype, neotype, Sabah, Sarawak 
Introduction 
The present paper is a precursor to a revision of Hoya R.Br. of Borneo. Its aim is to 
list all Hoya taxa occurring on the island of Borneo and their synonyms, clarify and 
standardize type citation, select lectotypes, epitypes and neotypes when necessary and 
provide an extensive list of isotypes and syntypes. 
The earliest description of a Hoya species that occurs in Borneo, H. multiflora 
Blume, was described by the German born Dutch botanist Carl Ludwig Blume in 1823, 
based, however, on Javanese materials. The first Hoya species based on a Bornean 
collection, H. imperialis Lindl., was published by Lindley (1846). Later, in 1880, 
Bentham published a peculiar leafless species with long photosynthetic peduncles 
endemic to Borneo, Astrostemma spartioides Benth. (now Hoya spartioides (Benth.) 
Kloppenb.). Until 1921 only nine Hoya species where known to occur in Borneo 
(Merrill, 1921). Nutt (2001) listed 21 species in an unpublished checklist. Lamb et al. 
(2014) estimated 60-70 species for Sabah alone. In the past 20 years almost 40 taxa 
(species and subspecies) of Hoya from Borneo have been described, mostly by Ted 
Green and Dale Kloppenburg (USA). The most recently published taxa have been 
described predominantly based on collections from Sabah and Sarawak (Rodda & 
Simonsson, 2011a, 2011b; Rodda & Simonsson Juhonewe, 2013a; Lamb et al., 2014; 
Rodda et al., 2014, 2016; Rodda, 2015a; Lamb & Rodda, 2016) with only one from 
Kalimantan (Rahayu et al., 2015). 
A guidebook to Hoya R.Br. of Borneo has been recently published (Lamb & 
Rodda, 2016) and includes a checklist of Bornean Hoya that lists 72 taxa (71 species and 
one subspecies) but does not deal with typification of names. The current bibliographic 
checklist of names is intended as a precursor to a formal taxonomic revision of the 
genus for Borneo. 
