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Card. Bull. Singapore 69(1) 2017 
A need for protection 
Limestone karst hills and caves are an integral part of our natural heritage that have 
taken millions of years to form and, therefore, cannot be sustainably exploited. 
Limestone hills are especially rich in biodiversity which is often found in no other 
habitats. Therefore, national conservation action plans must urgently be implemented 
to protect these hills. National programmes should include long-term holistic strategies 
that balance the use of limestone hills and the preservation of their unique biodiversity. 
There are potential non-destructive uses of limestone hills for their caves, possible 
sustainable bird’s nests harvesting, their value as scenic landscapes and monuments, 
their archaeological and cultural heritage, and their recreational value. 
Actions : Threatened species require conservation action plans that include more 
intensive surveys, particularly for endemic species and threatened species. Species 
categorised under guidelines from IUCN (2012) as Critically Endangered (CR) or 
Data Deficient (DD) hold the greatest conservation concern due to a combination of 
extreme rarity and loss of habitat. 
Legal status : Chua et al. (2009) suggested limestone hills should be included in the 
Permanent Forest Reserves network or that the protected status of Totally Protected 
Areas should be properly enforced. Microchirita species are restricted to limestone 
hills, so any disturbance to these limestone hills creates an impact on the included 
flora. 
Buffer zone : In Peninsular Malaysia, apart from the limestone hills within Taman 
Negara, it is rare to find a hill with any surrounding forest left intact (Kiew, 1991). 
Karst hills are a unique habitat for several rare and endemic plants. In Peninsular 
Malaysia an estimated 1250 species are found on limestone (which is 22% of the 
Peninsular Malaysia flora), of which at least 125 species are endemic to limestone. 
Microchirita species mostly grow at the base of hills, especially the more widespread 
species such as M. caliginosa , and it is therefore important to have a buffer zone 
around these hills. 
Awareness & education : To support the conservation of limestone hills, awareness 
of the threats to this habitat in the general public and by state authorities needs to be 
promoted. 
Material and methods 
Microchirita specimens were examined from the following herbaria: BK, BKF, BO, 
E, K, KEP, KLU, L, SAN, SAR, SING and UKMB (Thiers, continuously updated). 
Complete descriptions are based on herbarium specimens as well as observations 
on living material from field studies, together with materials cultivated in the FRIM 
