Aquilaria undetermined

Lee, S. Y. & Mohamed, R., 2016, Rediscovery of Aquilaria rostrata (Thymelaeaceae), a species thought to be extinct, and notes on Aquilaria conservation in Peninsular Malaysia, Blumea 61 (1), pp. 13-19 : 18

KEY TO THE AQUILARIA SPECIES IN

PENINSULAR MALAYSIA

1. Small tree 2–10 m tall, to 15 cm diam............... 2

1. Medium to large tree up to 40 m tall, 30–60 cm diam... 3

2. Leaves elliptic-oblong, ovate-oblong, dull and pubescent be- neath especially on the midrib, nerves and veins, sometimes glabrescent, shining on the upper surface, base cuneate to obtuse or rounded; apex acuminate. Fruit protruding from the floral tube, oblanceolate, base attenuate, apex abruptly acute................................... A. hirta

2. Leaves lanceolate, ovate-oblong, glabrous, shining on both surfaces, base obtuse, cuneate to attenuate; apex acumi- nate. Fruit protruding from the lateral slit of floral tube, obovate, obovate-oblong or oblanceolate, base long-narrowed, apex beak-like.......................... A. rostrata

3. Floral tube (calyx tube) cylindric. Calyx lobes much shorter than the tube, spreading. Leaves papery, usually glabrous on both surfaces, oblong, oblong-lanceolate or elliptic-oblong, 11–27 by 6–8.5 cm. Fruit obovoid, laterally compressed, slightly contracted in the middle, base abruptly narrowed to the elongate stipe.................... A. beccariana

3. Floral tube (calyx tube) cup- or bell-shaped. Calyx lobes slightly shorter or longer than the tube, spreading or reflexed. Leaves chartaceous, subcoriaceous, shining and glabrous above, glabrous or slightly hairy beneath, elliptic-oblong to obovate-oblong or oblanceolate, 4.5–12 by 1.5–5.5 cm. Fruit obovoid or obovoid-oblong or subcordate, never or slightly compressed, base cuneate....................... 4

4. Fruit obovoid or obovoid-oblong, never compressed, 3–4 by 2–3 cm. Stamens longer than the petaloid appendages with anthers emerging from the throat of the floral tube.................................... A. malaccensis

4. Fruit subcordiform, slightly compressed, 0.8–1.5 by 1–1.5 cm. Stamens shorter than or as long as petaloid appendages with anthers included in the floral tube.... A. microcarpa

CONSERVATION STATUS OF AQUILARIA IN PENINSULAR MALAYSIA

Malaysia is rich in Aquilaria diversity ( Table 6) and this leads to many names given by the local people. The general local name in the Peninsular Malaysia for A. malaccensis is ‘karas’ or ‘depu’. ‘Karas bulu’ or ‘chandan bulu’ is dedicated to A. hirta and ‘karas/chandan gunung’ is assigned to Aquilaria trees found at high elevations such as natural forests in the mountainous region. The precious agarwood produced from Aquilaria tree is known as ‘gaharu’. In 2005, the Forest Department of Peninsular Malaysia (FDPM) reported that the number of wild Aquilaria trees in natural forests of Peninsular Malaysia stood at more than 3 million individuals. This was based on a nationwide inventory conducted between 2002 and 2004 ( FDPM 2005). By now, a decade later, this number is expected to have steeply declined due to illegal agarwood harvesting activities and diminishing natural habitats due to conversion of forest to agriculture land.

It is more difficult to determine the conservation status for A. beccariana , A. microcarpa and A. rostrata as the information is limited. Although the two former species are recorded as abundant in Sabah and Sarawak, there is little available information on their presence in Peninsular Malaysia. Similar to A. rostrata , A. microcarpa in Peninsular Malaysia is also known from a single herbarium specimen, collected from Mersing, Johor. Another species reported from Mersing is A. beccariana ( Faridah-Hanum et al. 2009) . However, our excursions con- ducted in March 2015 revealed the reported site in present day as located next to an agriculture plantation. This could explain the disappearance of these two species from Mersing, or else they could not be found due to inaccessibility of their existing populations. Previous assessments by the forest department also gathered no new information on natural Aquilaria trees within that area. Aquilaria beccariana was also reportedly found in Kota Tinggi, Johor, but new collections or updates are not available to ascertain its status.

For A. rostrata , the forest department had carried out an extensive sampling effort but failed to relocate this species at Wray’s Camp, Gunung Tahan, Pahang. The population is believed to have disappeared owing to illegal agarwood harvesting (M. Mohd Nasir, FDPM, pers. comm.). Due to the difficulty of obtaining information on Aquilaria natural stands in Peninsular Malaysia, A. hirta and A. malaccensis have been considered for the conservation status Vulnerable (VU), while the remain- ing three species have been given the temporary status Data Deficient (DD) ( Lau & Chua 2011). However, the IUCN Red List of Threatened Species ( IUCN 2015) categorizes all the five species as Vulnerable (VU), except for A. rostrata , which is classified as Critically Endangered (CR) ( Table 6).