In many times, botanical expeditions offer great opportunities to the keen eyes. Two species of Sonerila were found and collected during a botanical survey at the summit trail of Gunung Ledang, Johor. The two species were Sonerila griffithii C.B.Clarke and S. tenuifolia Blume. The latter had a height of up to 50 cm tall, branching and bushy with a reddish stem. This species is usually found growing under shades at banks of rocky stream, wet rocky faces or damp hill slopes. In Gunung Ledang, the species was found growing on the mossy forest floor on the ridges under the tree and uncommon as only one population was found towards the summit.
Sonerila tenuifolia is easily recognised from its erect habit and the long leaf stalk (petiole of 0.5?1.8 cm long). The leaves are narrow and elongated lanceolate with a dimension of 2?6 cm long and 0.6?1.4 cm wide. The lamina is hairy on both surfaces, and the margin is denticulate. The leaf is thinly chartaceous when dried, and this may possibly explain the origin of its Latin name; tenuis (thin) and folium (leaf), referring to the leaf character.
The species has its inflorescence terminal or axillary, and there are always three flowers per inflorescence. The non-venulose petals (7?9 × 5 mm) and stigma are pale pink while the sagittated anthers are yellowish.
Sonerila tenuifolia is so far known from Java in Indonesia, and Malaysia (POWO, 2022). In Peninsular Malaysia, it is widespread and recorded from Johor, Kelantan, Negeri Sembilan, Pahang, Perak and Selangor on upper hill to montane forest areas. None of the other known species from the genus in Peninsular Malaysia shared similar leaf shape as of S. tenuifolia. However, S. tenuifolia recorded from Java resembles S. celebica Bakh.f. from Sulawesi by having an erect habit and terete stem, but the latter can be differentiated from the former species by its ovate to subovate leaves, obtuse tips and rounded to subcordate base, and the ovoid to oblong anther, while the petals are venulose (Kartonegoro, 2011).
Sonerila is a group of plants that are popular among horticulturists for its ornamental foliage. They are sought-after as decorative in terrariums or simply potted due to their attractive leave shapes, colours and veins formation. As for S. tenuifolia, despite its plain-green leaves, the denticulate margin made this species a potential ornamental plant.
