Rhododendron benomense Rafidah & A.C.Elliott, 2022

Rafidah, A. R. & Elliott, A., 2022, Rhododendron benomense Rafidah & A. C. Elliott (Ericaceae), a new name for Rhododendron obscurum Sleumer, a species endemic to Peninsular Malaysia, Edinburgh Journal of Botany 79 (413), pp. 1-4 : 2-3

Rhododendron benomense Rafidah & A.C.Elliott , nom. nov.

Rhododendron obscurum Sleumer , Reinwardtia 5: 104 (1960), nom. illeg., non Rhododendron obscurum Franch. ex Balf.f. , Notes Roy. Bot. Gard. Edinburgh 13: 278 (1922).

– Type: Peninsular Malaysia, Pahang, on top of Gunung Benom , 23 v 1930, Strugnell F.M.S. 22344 [protologue erroneously records it as 223U] (holotype KEP [ KEP62885 ] , isotype L, fragment plus photograph [ L0007648 ]) . Figures 1 , 2 .

Proposed IUCN conservation category. Vulnerable (VU D2) ( IUCN Standards and Petitions Subcommittee, 2019). Several scattered populations were found during a survey of Gunung Benom in 2009 ( Ummul-Nazrah et al., 2011), but no estimate of numbers was made. Although trekking is popular at this location, it has limited impact on the habitat. Gunung Benom, the only known locality of Rhododendron benomense , is part of Krau Wildlife Reserve, which offers some protection. The pressures and threats reported for Krau Wildlife Reserve are focused primarily on the lowland forest area of the reserve ( Birdlife International, 2021), not the summit of Gunung Benom where this species occurs. The restricted distribution (area of occupancy c.8 km 2, based on summit area above the minimum recorded altitude) and the presumably small size of the population (fewer than 250 mature individuals) leave Rhododendron benomense extremely vulnerable to stochastic events that could critically endanger it or cause its extinction.

Additional specimens examined. MALAYSIA. Peninsular Malaysia: Gunung Benom , Pahang, Summit, Open Leptospermum woodland, 6740 ft, common bush, Flowers orange-red, 19 iii 1967, Whitmore FRI 3284 ( KEP, L [ L0614189 ]) ; Gunung Benom , Pahang, Summit, (3°49.83′N, 102°06.41′E), 2065 m, Flowers orange, 13 xi 2009, Mohd. Hairul M.A. et al. FRI 69875 ( KEP [ KEP187085 ], SAN) .

It is our recommendation that additional survey work be carried out to ascertain the population size of Rhododendron benomense , to collect germplasm for storage, and to establish a genetically diverse ex situ conservation collection of this species in Peninsular Malaysia.

Figures

Figure 1. Habit of Rhododendron benomense Rafidah & A.C.Elliott. Photograph: Mohd Hairul, M.A.

Figure 2. Inflorescence detail of Rhododendron benomense Rafidah & A.C.Elliott. Photograph: Mohd Hairul, M.A.