1. Introduction

Habitat and Distribution, Native Continent

Oncosperma fasciculatum is endemic to Sri Lanka, making it the only Oncosperma species found outside the Southeast Asian mainland and archipelago. This rare palm is restricted to the lowland rainforests of southwestern Sri Lanka, particularly in the wet zone districts of Kalutara, Ratnapura, and Galle, from sea level to 600 meters elevation. It inhabits areas with annual rainfall exceeding 3,000mm, showing a strong preference for riverbanks, marshy areas, and forest edges where the water table is high. The species has suffered severe habitat loss, with remaining populations fragmented in forest reserves such as Sinharaja, Kanneliya, and Nakiyadeniya. Unlike its congeners, O. fasciculatum has adapted to the specific climatic conditions of Sri Lanka's southwestern monsoon forests. These unique forests experience two distinct monsoon seasons, creating a perpetually humid environment that supports this moisture-loving palm. The species often grows in association with other endemic Sri Lankan plants, forming part of the unique biodiversity hotspot that characterizes the island's wet zone forests.

Native Continent

Taxonomic Classification and Scientific Classification

Synonyms

• Oncosperma ceylonicum Becc. (illegitimate name)
• Areca fasciculata Wall. ex Thwaites (basionym)
• Sometimes misidentified as O. tigillarium in older literature
• Occasionally confused with O. horridum in botanical collections

Common Names

• English: Ceylon nibung palm
• English: Sri Lankan oncosperma
• Sinhala: Katu-kitul ("spiny kitul")
• Sinhala: Heen-kitul ("small kitul")
• Chinese: 锡兰刺棕 (Xīlán cì zōng)
• Tamil: இலங்கை முள் பனை (Ilaṅkai muḷ paṉai)

Expansion in the World