Hoya bukitrayaensis (Apocynaceae), a new species from Kalimantan, Indonesia

Roland Ahmad; Yuda R. Yudistira; Budi Suriansyah; Dodi Marsaidi; Agusti Randi; Wendy Mustaqim

doi:10.7751/telopea21636

Authors

Roland P.P. Ahmad Yayasan Tumbuhan Asli Nusantara https://orcid.org/0000-0003-1615-471X
Yuda R. Yudistira Yayasan Konservasi Biota Lahan Basah, Surabaya https://orcid.org/0000-0003-1354-486X
Budi Suriansyah Biodiversity Expedition TaNa KaYa, Pontianak
Dodi Marsaidi Balai Besar Taman Nasional Bukit Baka Bukit Raya
Agusti Randi Nusantara Climate Initiative, Jakarta
Wendy A. Mustaqim Fakultas Sains dan Teknologi, Universitas Samudra https://orcid.org/0000-0001-9902-830X

DOI:

https://doi.org/10.7751/telopea21636

Keywords:

climbers, montane plants, taxonomy

Abstract

A new species, Hoya bukitrayaensis R.P.P.Ahmad, Yudistira & Mustaqim, is described based on material collected from Mount Bukit Raya, Central Kalimantan, Indonesia. The species is characterized by a pubescent corolla and a floral morphology that closely resembles that of H. kastbergii Kloppenb. However, the new species differs from H. kastbergii in its lanceolate leaf blade with a pointed tip (vs ovate with a rounded tip), shallowly lobed corolla (vs deeply lobed), and 3-lobed (vs entire) outer coronal lobes. A detailed morphological comparison with these related species is provided to highlight diagnostic features and support its recognition as a distinct taxon, and photographs of live plants are provided.

Author Biographies

Yuda R. Yudistira, Yayasan Konservasi Biota Lahan Basah, Surabaya

[Note: No direct email]
Budi Suriansyah, Biodiversity Expedition TaNa KaYa, Pontianak

Note no direct email
Dodi Marsaidi, Balai Besar Taman Nasional Bukit Baka Bukit Raya

Note no direct email

References

Ahmad RPPA, Zulfadli, Rahayu S, Rodda M (2021) One new species and a new record of Hoya (Apocynaceae, Asclepiadoideae) from Sulawesi, Indonesia. Phytotaxa 502(1): 79–85. https://doi.org/10.11646/phytotaxa.502.1.5

Cámara-Leret R, Frodin DG, Adema F, Anderson C, Appelhans MS, Argent G, Arias Guerrero S, Ashton P, Baker WJ, Barfod AS, Barrington D, Borosova R, Bramley GLC, Briggs M, Buerki S, Cahen D, Callmander MW, Cheek M, Chen CW, Conn BJ, Coode MJE, Darbyshire I, Dawson S, Dransfield J, Drinkell C, Duyfjes B, Ezedin Z, Fu L, Govaerts R, Heatubun CD, Hind DJN, Hoch P, Homot P, Hovenkamp P, Hughes M, Jebb M, Jennings L, Jimbo T, Kessler M, Kiew R, Lehnert M, Leme E, Leong-Škorničková J, Lim CL, Loo A, Madsen JE, Mahyuni R, Meijer W, Middleton D, Nagamasu H, Newman M, Nic Lughadha E, Poulsen AD, Prance G, Quakenbush J, Raes N, Rodda M, Rogers Z, Schuiteman A, Schwartsburd P, Scotland R, Simmons M, Simpson D, Stevens P, Sundue M, Testo W, Trias-Blasi A, Utteridge T, Walsingham L, Webber B, Wei R, Weigend M, Weston P, Widjaja E, Wieringa J, Wood J, Zhang L, Zizka A (2020) New Guinea has the world’s richest island flora. Nature 584: 579–583. https://doi.org/10.1038/s41586-020-2549-5

Costea M, Barcelona J, Nickrent D, Nixon KC, Pelser P (2025) PhytoImages. http://phytoimages.siu.edu/ (accessed Oct. 2025)

Davies NMJ, Drinkell C, Utteridge TMA (2023) The Herbarium Handbook. New edition. Royal Botanic Gardens Kew: Richmond.

Forster PI, Liddle DJ, Liddle IM (1998) Diversity in the genus Hoya (Asclepiadaceae Marsdenieae). Aloe 35: 44–48.

Kloppenburg RD (2003) Hoya kastbergii. Fraterna 16(4): 1–5. https://archive.org/details/fraternaofficial1614inte/page/n71/mode/2up

GBIF (2025) Global Biodiversity Information Facility. https://www.gbif.org (accessed Oct. 2025)

Lamb A, Gavrus A, Emoi B, Gokusing L (2014) The Hoyas of Sabah, a commentary with seven new species and a new subspecies. Sandakania 19: 1–89. https://archive.org/details/sandakania-19-001-089

Lamb A, Rodda M (2016) A guide to Hoyas of Borneo. Natural History Publications (Borneo): Kota Kinabalu.

Pelser PB, Barcelona JF, Nicrent DL (2011-onwards) Co’s Digital Flora of the Philippines. Available at: www.philippineplants.org (accessed Oct. 2025)

Rahayu S, Ahmad, RPP, Rodda M (2022) Hoya of Sulawesi, Indonesia: A checklist, two new species, a new subspecies and six new records. Gardens’ Bulletin Singapore 74(2): 207–221. https://doi.org/10.26492/gbs74(2).2022-07

Rodda M (2017) Index of names and types of Hoya (Apocynaceae: Asclepiadoideae) of Borneo. Gardens’ Bulletin Singapore 69: 33–65. https://doi.org/10.26492/gbs74(1).2022-08

Rodda M, Rahayu S (2022) Nine new species and one new subspecies of Hoya (Apocynaceae: Asclepiadoideae) from Borneo. Gardens’ Bulletin Singapore 74: 101–129. https://doi.org/10.3850/S2010098116000039

Rodda M, Rahayu S (2025) A new night-blooming species of Hoya (Apocynaceae: Asclepiadoideae) from Borneo. Nordic Journal of Botany 2025: e04787. https://doi.org/10.1002/njb.04787

Schlechter R (1913) Die Asclepiadaceen von Deutsch-Neu-Guinea. Botanische Jahrbücher für Systematik, Pflanzengeschichte und Pflanzengeographie 50: 81–164. https://www.biodiversitylibrary.org/item/712#page/87/mode/1up

Schumman K, Lauterbach K (1905) Die Flora der Deutschen Schutzgebiete in der Südsee. Gebrüder Borntraeger: Leipzig. https://doi.org/10.5962/bhl.title.717

Seemann BC (1861) Plantae Vitiensis. Bonplandia, Zeitschrift für die gesamte Botanik 9: 253–262. https://www.biodiversitylibrary.org/item/89394#page/261/mode/1up