Livistona tahanensis is a species of medium-sized palm tree of the genus Livistona, found on only one mountain top in Pahang, Peninsular Malaysia. In Malay the palm is known as Tahan serdang, or as daun tau. T.C. Whitmore, writing in 1970, describes that the palms are seen after a four days' hike from Kuala Tahan, up the ridge behind Kuala Teku through tall dipterocarp jungle, until, suddenly, at in altitude up the slopes of the remote Gunong Tahan (Tahan mountain), the dense vegetation breaks and a low, stunted, small-leaved, upper montane forest takes over, continuing to , and in sheltered locations to . Out of this elfin forest, the stiff crowns of Tahan serdang grow as emergents, and the air is filled with the sound of the wind sighing through them. The palm hearts are eaten by wild elephants. Taxonomy Livistona tahanensis was first formally described as a new species by the Italian palm specialist Odoardo Beccari in 1921. The name had in fact already been used in 1915 by Henry Nicholas Ridley, published in An annotated list of plants of Gunung Tahan, Pahang, Malaysia, with the understanding that Beccari would soon provide a description. The holotype was collected by L. Wray and H. C. Robinson at 1,000 metres altitude on Gunung Tahan, it is their collection number 5355, and it was kept at the herbarium of the Perak Museum in Malaysia. Description This plant is a medium-sized, hermaphrodite fan palm, which grows up to in height, with a trunk diameter at breast height. The trunk has narrow leaf scars, and a narrow amount of space between each successive one, although this is usually obscured by the petiole stubs, which remain persistent, not falling off, for most of the length. The crown of the palm is globose (round), and it contains some 30 to 40 leaves. The leaves are costapalmate. For a Livistona the leaves are quite small: long, by wide. They are stiff and flat to undulate, subcircular, and divided regularly, splitting up the leaf blade into narrow segments or pinnae from its middle to some 58% of its length -these are forked or bifurcated at their end deep, or 16% of their length, and are not drooping, but rigid, and stiffly held up. There are 40 to 50 segments. The leaf blades are dark green on their upper sides. On mature trees the leaves are grey to grey-green