Aleisanthia rupestris – Botanical Wonder of Peninsular Malaysia

Woolly hairy leaves of A. rupestris. Click on the photo for a close-up of the woolly leaf surface (Photo from: M. Sugumaran).


Aleisanthia rupestris (Ridl.) Ridl. is one of the five endemic plants that can only be found in the Klang Gates Quartz Ridge [1][2][3][4], in the Selangor state of Peninsular Malaysia. This botanical gem, a member of the Rubiaceae, is highly dependent on the rock enviroment on the ridge for survival. The quartz ridge spans 14 km long and 200 m wide, and soars to 380 m, making it the largest natural quartz dyke in the world [5]! Read on to find out how this sedentary shrub struggles for survival in the fire-prone ridge environment, and pits itself against invasive weeds, luxurious residential estates, and highway development plans!

The Klang Gates Quartz Ridge (Photo from Pencinta Alam, Jan 2011).

Map showing location of Klang Gates Quartz Ridge (yellow bar) in Selangor state of Peninsular Malaysia (Photo from

Habitat and Population Size:

Aleisanthia rupestris grows in between the cracks of quartzite rocks [6], especially in exposed areas with full sunshine [4]. It is rare or absent in shaded areas [4].


Exposed rockfaces where A. rupestris thrives (Photo from M. Sugumaran).


Its population size has not been formally assessed but Dr. Wong Khoon Meng (a Rubiaceae expert whom we consulted) reckoned that tens of thousands probably occur on the ridge (K. M. Wong, pers. comm.).


Morphology and Life History [6]:

Aleisanthia rupestris is a shrub that grows to about 1 m high. The leaves are oval, slightly bluish, and has a wool-like hairy surface.


Shrub habit of A. rupestris (Photo from M. Sugumaran).


Its cream, bell-shaped, and bisexual flowers are pollinated in an interesting manner. While in the bud stage, its pollen grains are already deposited onto its own immature stigma. As the flower opens, the stigma is exposed to pollinators which deposit the pollen onto the mature stigma of another flower! The petals last for a single day, wilting soon after they open. Sometimes, ants create holes at the base of the corolla tube in the serach for nectar. 

Cream flower of A. rupestris. Some ants are nectar robbers which pierce the base of flowers to steal nectar (Photo from M. Sugumaran).


Interestingly, almost all of its ovaries develop into fruits. Its fruits are dry capsules that split open to release its numerous small brown seeds. There are still many questions regarding its life span, germination, and reproductive success that awaits further investigation!


Fruits of A. rupestris split open to expel their seeds (Photo from M. Sugumaran).


This species has a plethora of adaptations, such as small leathery leaves, which enable  it to thrive in dry and water-scarce environments. The dry and nutrient-poor conditions on the ridge relative to its adjacent forests result in a species-poor community, where A. rupestris could avoid competition with other plants. Hence, it should not be surprising that the Klang Gates Quartz Ridge is the only habitat in this planet that provides appropriate conditions for the survival of this species.


Leathery leaves of A. rupestris enables its survival in dry rocky conditions on the ridge (Photo from Vincent Ong).


Threats and Conservation:

The threats that A. rupestris faces change through time, diminishing when short-term conservation goals are realised but returning when development plans are revived. To date, there is no specific conservation action to protect the species per se, but there are numerous attempts to conserve its unique habitat. After all, the conservation of A. rupestris fully depends on the preservation of its unique “island” habitat in its pristine state (K. M. Wong, pers. comm.).

As early as 1936, the Klang Gates Wildlife Reserve was established at the ridge [3][4]. The greatest threat then was persistent fires during dry spells [3]. Some plants could regenerate easily but A. rupestris is susceptible to fires [3]. In the 1990s, the ridge faced new threats with increasing urbanisation. The ridge is adjacent to the city of Kuala Lumpur. Thus, the land around the quartz ridge is a choice residential location where residents can enjoy the amenities of city and nature [7][8] – the best of both worlds!

Luxurious condominiums near the ridge offer a breathtaking view of the ridge vegetation and panoramic view of skyscapers in the city of Kuala Lumpur (Photo from K. M. Wong).

Landed properties encroaching the ridge (Photo from K. M. Wong).

The ridge is also a popular recreational and eco-tourism site, exposing it to human impacts such as trampling, barbecues, and campfires by hikers [9][10]. Razed and disturbed sites are often colonised by a dense cover of large-sized invasive weeds, e.g., Clidemia hirta and Dicranopteris linearis, that excludes establishment of the small-sized and fire-sensitive A. rupestris [4][10].

The invasive weed, Clidemia hirta, grows in rock crevices too (Photo from K. M. Wong).

Dense stand of Dicranopteris linearis prevents establishment of A. rupestris (Photo from K. M. Wong).

To increase its protection, Non-Governmental Organizations (NGOs) such as The Malayan Nature Society (MNS) and Treat Every Environment Special Sdn Bhd (TrESS) have proposed turning the ridge into a State Park in 1997 [11]. In 2005, the ridge was included as part of the Selangor State Park [4]. This prohibits further development of the ridge, with the exception of ecotourism, education, or research [12].

Recently, the quartz ridge is under threat again! In order to ease traffic congestion, the Kuala Lumpur Outer Ring Road (KLORR) was planned for construction and was supposed to cut through the ridge, despite the State Park guidelines [12]. If the highway plans went ahead, populations of A. rupestris would be fragmented and become vulnerable to random environmental fluctuations [14].

Fortunately, NGOs and the public have written many online petitions and blogs (e.g.,, to campaign for further protection of the ridge. Eventually, the authorities decided to build a tunnel under the quartz ridge to reduce damages to the vegetation [12], but the war does not end there! Aleisanthia rupestris faces perennial threat as the Klang Gates Quartz Ridge is under intense development pressure that takes precedence over conservation.

Proposed Conservation Status:

Aleisanthia rupestris is not listed under the International Union for Conservation of Nature (IUCN) Red List of Threatened Species. We propose that it should be classified under the Near Threatened status (does not qualify for Critically Endangered, Endangered, or Vulnerable now, but is close to and likely to qualify for Vulnerable in the near future) given that:

(1) Its extent of occurrence and area of occupancy is certainly less than 20,000 km2 and 2000 km2 respectively because the ridge merely occupies a tiny area of 2.8 km2.

(2) It is known to exist in no more than 10 locations (K. M. Wong, pers. comm.).

(3) The state of decline in number of locations or mature individuals is currently unknown (K. M. Wong, pers. comm.) but may occur in the near future if development plans are revived.

Given the recurring threats that A. rupestris faces, conservation remains urgent despite its Near Threatened status.

Type specimen of A. rupestris (Photo from

Prognosis for Conservation:

It is impractical to bring A. rupestris out of the ridge for ex-situ conservation in botanic gardens; leaving them in their natural habitat is the best means to conserve the species (K. M. Wong, pers. comm.). Thus, we must keep the ridge in its pristine state!

  • Economic Valuation: The monetary value of ecosystem services of the ridge should be estimated [13] so that preservation of the ridge is economically competitive with other pressing development needs.
  • Enforcement: Why are development plans approved on gazetted protected areas? Is Selangor State Park merely a Paper Park? Conservation management and law enforcement on the ground must be improved. We suggest that NGOs and the public actively strive for the nomination of the Klang Gates Quartz Ridge as a UNESCO World Heritage Site. This would provide legal protection under International Law and the Geneva Convention.
  • Research: The ecological charateristics of the plant, such as its pollinators, herbivores, and the genetic diversity of current populations should be investigated [4]. These studies would reveal sound approaches towards species-specific conservation.
  • Public Education: Formally organised tours by experienced guides could be conducted on the ridge to increase public awareness of its unique features [4]. An entrance fee could also be imposed on visitors to fund the maintanance of the ridge and the conservation of its endemic species. Malaysian botanists could publish a book about natural history of the Klang Gates Quartz Ridge, with anecdotes of sucessful conservation and painful experiences of species extinction. The charismatic flowers of A. rupestris may also be incorporated into the design of souvenirs, T-shirts, and iPhone covers, e.t.c., to promote local pride and conservation interest.

With legislative support, greater public awareness, and synergised conservation efforts, we are hopeful that A. rupestris – a botanical wonder of Peninsular Malaysia – can be enjoyed for a long time into the future!


We would like to thank Dr. Wong Khoon Meng, Keeper of the Singapore Herbarium (SING) and Assistant Director of Research and Conservation of the Singapore Botanic Gardens, for offering his valuable insights on A. rupestris.


[1] Reid, J. A., 1951. Klang Gates and Bukit Takun: Reflections of an amateur botanist. Malay Nature Journal 5: 109–123.

[2] Reid, J. A., 1959. Plants of the Quartz Ridges. Malayan Nature Journal 14: 22–32.

[3] Kiew, R., 1982. The Klang Gates Ridge. Malayan Nature Journal 36: 22–28.

[4] Wong K. M., M. Sugumaran, D. K. P. Lee & M. S. Zahid, 2010. Ecological aspects of endemic plant populations on Klang Gates quartz ridge, a habitat island in Peninsular Malaysia. Biodiversity and Conservation 19: 435–447.

[5] Cheang, M., 2004. Klang Gates Quartz Ridge – Precious monument. The Star (Malaysia), 23 March 2004.

[6] Tange, C., 1996. Studies in SE Asiatic Rondeletieae I: The West Malaysian endemic genus Aleisanthia (Rubiaceae). Nordic Journal of Botany 16: 563–570.

[7] Prasad, C., 2010. What makes Melawati matter. New Straits Times (Malaysia), 16 July 2010.

[8] Gunaprasath, 2010. Living beyond indulgence. New Straits Times (Malaysia), 16 July 2010.

[9] Tan, C. L., 1998. The Giant that needs protection. The Star (Malaysia), 14 April 1998.

[10] Wise, R. & Zahid M. S., 1999. Aleisanthia rupestris: Botanical gem of Kuala Lumpur. Plant Talk 18: 30.

[11] Ong, H., 1998. Calls to turn ridge area into a park. The Star (Malaysia), 10 March 1998.

[12] Gan, P. L., 2010. NGOs: No to KLORR, Protect Selangor State Park. Selangor Times, Issue 6, Dec 31 2010–Jan 2 2011.

[13] Pek, C. K., C. H. Tee & P. Y. Ng, 2010. Hill recreational and services valuation: A case study of Taman Melawati Hill. Sunway Academic Journal 7: 33–47.

[14] Ellstrand, N. C. & D. R. Elam, 1993. Population genetic consequences of small population size: Implications for plant conservation. Annual Review of Ecology and Systematics 24: 217–242.