Rhododendron chamahensis Rafidah, 2012

Rafidah, R., 2012, Rhododendron chamahensis (Ericaceae), a new species from Peninsular Malaysia, Blumea 57 (2), pp. 114-115 : 114-115

Rhododendron chamahensis Rafidah , sp. nov. — Plate 1 , 2

Rhododendron seimundii similis sed foliis longitudine quam latitudine 4-plo (non 2–3-plo) excedenti apice glande protusa nulla (in R. seimundii glande hujusmodi praesenti), bracteis rotundatis (non filiformibus),pedicellis 1.6–2 cm longis (non 0.5 –1 cm), ovario dense indumentoso (non lepidoto) differt. — Typus: P. Wilkie et al. FRI 72071 (holo KEP; iso E), Peninsular Malaysia, Kelantan, Gua Musang , Gunung Chamah , 3 Aug. 2010, N5°12'22.20" E101°34'16.30" .

Etymology. The epithet refers to the locality, Gunung Chamah.

Epiphytic shrub. Scales scattered, sessile, with an entire margin, the centre not dark-coloured. Branches slender, c. 20 cm long, sometimes lepidote; internodes 2.2 –3.5 cm long. Leaves in pseudowhorls of 4 – 6; petiole pale green, 4 –7 mm long, slightly glaucous, glabrescent; lamina narrowly elliptic to oblong elliptic, 2 – 6.5 by 0.5–1.5 cm, in living material dark green above and beneath, coriaceous, sometimes scattered lepidote above and beneath, base attenuate, margin slightly crenulate, sometimes entire, slightly revolute, apex obtuse, tip without

Character R. chamahensis R. seimundii

Habit epiphyte terrestrial

Petiole

length (mm) 4–7 2–4

indumentum glabrescent lepidote

Lamina

shape narrowly elliptic to oblong-obovate to narrowly oblong elliptic elliptic

length by width (cm) 2–6.5 by 0.5–1.5 1.3–2.8 by 0.6–0.9

length: width ratio 4: 1 2–3: 1

tip of apex without a gland ending in a small protruding gland

Bracts

shape rounded filiform

size (mm) 5 by 5 8 by 2

Pedicel length (cm) 1.6– 2 0.5–1

Corolla

colour pure white white with red scales

lobe size (mm) 9–11 by 8–10 15–25 by 14–26

Anthers white maroon

Ovary densely hairy densely lepidote

gradually attenuate into the style, style whitish green, 12–15 mm long, sparsely hairy to minutely hairy towards the stigma, stigma capitate, c. 1.5 mm wide. Fruits and seeds unknown.

Distribution — Endemic in Peninsular Malaysia, Kelantan: known only from Gunung Chamah in the Gua Musang district.

Ecology — A rare species collected from the lower montane forest at altitudes of 1200 –1700 m (not from the peak) growing as an epiphytic shrub collected from a fallen tree by the river. a protruding gland; midrib deeply sunken above, strongly prominent beneath, lateral veins scarcely visible. Inflorescence a 2 – 3-flowered umbel; perulae pale green, rounded, c. 5 by 5 mm, membranous, minutely rusty hairy outside, glabrous inside; pedicel pale to whitish green, 1.6 – 2 cm long, slender, minutely hairy. Flowers: calyx pale green, 2.5 mm wide, lobes rounded oblique, hairy outside, glabrous inside; corolla pure white, rotate-campanulate shaped, c. 18 mm long, c. 22 mm wide, glabrous, tube narrowly cylindric, short, 6 –9 mm long, 3– 4 mm wide at base, 6–7 mm wide below the lobes, lobes spreading, erect, broadly obovate, apex rounded, 9–11 by 8–10 mm; stamens 8–10, filaments white, c. 1.6 cm long, hairy at the base, anthers white, 2 mm long, 1 mm wide; nectary (disc) black when dry, shortly cylindric, less than 2 mm high; ovary pale green, 2 – 4 mm long, c. 2 mm wide at base, densely hairy,

Other specimen examined. PENINSULAR MALAYSIA, Kelantan,Gua Musang,

Gunung Chamah, 30 July 2010, Ong et al FRI 71142 ( KEP) .

Conservation status — Rare (RA).

Figures

Plate 1 Scales of Rhododendron chamahensis Rafidah.

Plate 2 Rhododendron chamahensis Rafidah. a. Habit; b, c. flow- ers. — Photos by P.T. Ong and K. Imin.