Vatica najibiana Ummul-Nazrah, 2018

Ummul-Nazrah, Abdul Rahman, Mohd Hairul, Mohd Amin, Kamin, Imin, Kiew, Ruth & Ong, Poh Teck, 2018, Vatica najibiana (Dipterocarpaceae), a new species from limestone in Peninsular Malaysia, PhytoKeys 98, pp. 99-106 : 99

Vatica najibiana Ummul-Nazrah sp. nov. Figures 1 , 2

Diagnosis.

Amongst the Vaticas with a half inferior ovary, it groups with Vatica harmandiana and V. odorata (Griff.) Symington subsp. odorata . Vatica harmandiana occurs on limestone hills and rocks but is different in having leaves that are elliptic-lanceolate, leaf base cuneate and nut diameter 7-10 mm as oppose to the obovate-elliptic leaf, leaf base cordate-subcordate and nut diameter of 5-6 mm in V. najibiana . Vatica odorata subsp. odorata is closely similar to the new species but can be separated by its elliptic-oblong leaf, leaf base obtuse, leaf apex acuminate, nut diameter 8-9 mm and occurrence in lowland and hill forest (Table 1 ).

Type.

Peninsular Malaysia. Kelantan, Gua Musang District, Relai Forest Reserve (Ktn 50), 05°02'47.8"N, 102°11'43.6"E, 19 October 2016, Ummul-Nazrah et al. FRI 86369 (holotype KEP!; isotypes K!, SAN!, SING!) .

Description.

Small tree, 5-7 m tall; bole to 15-17 cm diameter, without buttresses. Bark smooth with faint horizontal rings, dark brown with white lichen patches; inner bark pale yellow, exuding clear sap when cut. Twigs robust, 3-5 mm diameter, covered with 6-15-armed stellate hairs, 94-169 µm diameter, glabrous when mature, older twigs terete. Leaves when young brown rusty beneath, glabrous when mature; petioles 0.8-1.5 cm long, 0.1-0.2 cm wide, densely covered with stellate hairs, caducous when mature, drying dark brown; lamina obovate to elliptic, (3-)5-10.2 × 1.5-5 cm, thickly chartaceous, bullate, green on both surfaces when fresh, base cordate to subcordate, margin entire and recurved, apex acute; midrib prominent on both surfaces; lateral veins (6-)7-10 pairs, prominent below, slightly raised and visible above, ascending to margin; intercostal veins reticulate-scalariform and slightly conspicuous on both surfaces. Flowers: (dry) pedicels with velvety brown stellate hairs; calyx 5-lobed, elliptic, 4-7 × ca. 1 mm, densely covered with stellate hairs on both surfaces, apex acute; petals narrowly elliptic, ca. 6 × 2 mm, glabrous outside, inside from base to tip completely covered with 6-10-armed stellate hairs, 77-120 µm diameter. Infructescence axillary, near apex of leafy shoot, ca. 4 cm long, densely covered with rusty stellate hairs, branching once or twice, densely covered with stellate hairs; first branches with 1-7 fruits along axis, nodes 4-5 mm apart. Fruits: stalks 1-2 mm long, ca. 1 mm thick at base, covered with caducous stellate hairs; in life mature calyx red-brown, chartaceous, lobes 5, 2-3 larger than rest, attached to half inferior ovary, above forming a cup, glabrous outside, inner part at base completely covered with stellate hairs, lobes elliptic, apex rounded with 5 longitudinal prominent veins on the adaxial surface, 2.3-3.3 × 0.5-0.8 cm; shorter lobes 0.8-1 × ca. 0.2 cm; nut ovoid, 5-6 mm diameter, with persistent stigma, densely covered with stellate hairs, half hidden within calyx.

Distribution.

Endemic in Peninsular Malaysia, known only from Kelantan (Relai Forest Reserve, Gua Musang) and Pahang (Gua Tanggang, Merapoh).

Etymology.

This species is named in honour of the Prime Minister of Malaysia, Dato’ Sri Mohd Najib bin Tun Abdul Razak, for his strong interest in nature conservation and protection of the environment.

Provisional conservation status.

Endangered B2ab(iii). This species is known from the summit of two isolated karst limestone hills in Relai Forest Reserve, Gua Musang District, Kelantan and Gua Tanggang, Merapoh, Pahang, about 40 km apart ( Liew et al. 2016). Together they have an area of occupancy of less than 10 km2 (Figure 3 ). The Relai Forest Reserve is classified as a permanent forest reserve but is currently threatened by encroachment by oil palm plantations that pose a high risk of burning to the limestone vegetation, as well as disturbance from ongoing logging in the Sungai Relai Forest Reserve. Gua Tanggang in Merapoh, on the other hand, is situated outside of Taman Negara which means that it is not in a protected area.

Habitat.

It is an emergent tree on the rugged summit of karst limestone at 178-520 m altitude growing in rock fissures with a thick layer of leaf litter.

Phenology.

Fruiting specimens were collected in Relai Forest Reserve in October and Gua Tanggang in early August; complete flowers not seen but in October, many calyces and a few petals were collected.

Additional specimen examined.

Peninsular Malaysia. Pahang, Lipis District, Merapoh, Gua Tanggang, 4.410000N, 102.055000E, 520 m alt., 6 August 1996, Saw et al. FRI 44774 (KEP!)

Figures

Figure 1. Vatica najibiana. A Plant in its natural habitat B Bole C Inner bark D-E Leafy shoots with infructescences F Fruit. (Photographs by K. Imin & A. R. Ummul-Nazrah).

Figure 2. Vatica najibiana. A Leafy shoot with fruits B Calyx C Petal D-E Fruit F Long & short calyx lobes of fruit G Stellate hair H Fruit nut. (Drawn by N. Mohamad-Aidil from Ummul-Nazrah et al. FRI 86369).

Figure 3. Distribution of Vatica najibiana in Peninsular Malaysia.