Paraboea bakeri (Gesneriaceae) is a perennial herb with its leaves congested in a rosette. The petioles can reach to 5 cm long and are covered by brownish matted hairs. Its lamina is ovate with a rounded to acute apex and a serrate margin. The upper surface is covered in dense pubescent hairs while the lower surface is covered with brownish matted hairs. Paraboea bakeri produces axillary inflorescences seemingly capitate due to the extremely reduced primary and secondary branches. They are shorter than the leaves, are few-flowered. Matted brown hairs cover the inflorescence and calyx. The calyx is nearly as long as the capsule and has 5 lanceolate lobes. The corolla is completely white with 5 lobes and is minutely pubescent outside and glabrous inside. The corolla tube extends for at least half the corolla length. The anthers are pale yellow. The pistil is hairy with the ovary tapering smoothly into an indistinct style. It has a narrowly ovoid capsular fruit that is not twisted and is covered in dense, minute hairs.
Paraboea bakeri is an endemic species in Pahang, Malaysia. It can be found only in small shaded populations on the limestone hills in two localities; Bukit Sagu and Bukit Tenggek, all near Kuantan, Pahang. Both hills are in the process of being totally destroyed by quarrying activities. Because of these activities, in line with the IUCN conservation categories, the species is assessed as Critically Endangered (CR B2b(iii) + c(iv)). To conserve this species, which is in imminent danger of extinction, a plant rescue project was initiated to collect plants from these two hills, to culture and multiply them ex situ and then to reintroduce them into similar habitats on nearby limestone hills.
Recent field collection carried out on Bukit Sagu and Bukit Tenggek brought back plants to the FRIM nursery for propagation. Half the live plants collected survived and are growing well in the nursery. Propagation using mature leaves from cuttings made by cutting across the lamina or midrib were not successful. All leaf cuttings started to rot after being propagated for three days. Fortunately, a dried seed capsule was found attached to a live plant. The capsule was carefully scraped open, and 26 minute seeds were extracted. Seeds were germinated in sterile basal Murashige and Skoog (MS) nutrient media. Germination started after 3 weeks and achieved about 85% germination rate. The in-vitro seedlings have grown well and regenerated new shoots after sub-culturing. After many repeated acclimatization attempts, tissue culture plantlets were found to survive better in a good drainage soil mix with the addition of some soil collected from limestone hills. In the near future, when these ex-situ Paraboea bakeri plants are ready they will be reintroduced back to nature in a similar habitat on a limestone hill (Bukit Charas) that is safe from quarrying.
