三角椰子（学名：Dypsis decaryi），又名三角槟榔，是原产于马达加斯加雨林的一种棕榈科植物。它们可以高达15米，但在原产环境以外却不能长得那么高，因在种植上还算是新的品种。叶子长约2.5米，在近树干部份向上弯曲，逐步向尖端弯曲约1米。叶子基部在三个部份长出，形成一个三角形，故得此名。花朵从叶下长出，呈黄色及绿色。果实呈黑色及圆形，但不可吃，直径长2.5厘米。它们全年也会开花，呈色彩鲜艳。

三角椰子可以作为观赏植物，但要在开放的地方才可以显示它们独有的形态。它们喜欢阳光及定时浇灌，也可忍耐一些干旱及阴暗。砂质土壤较适合它们。由于移植它们的效果并不理想，故它们并不适合在商业种植。它们的果实具有高度养份。它们生长得很快，种子在一个月内就会发芽。

Dypsis decaryi is a palm tree commonly known as the Triangle palm. It is indigenous to the Madagascan rainforest. Some specimens grow to a height of some 15 metres in the wild. It is relatively new to cultivation however, so outside its native habitat it rarely achieves anything like that height. The leaves are about 2.5 metres in length, growing almost upright from the trunk and arching gracefully outward about a metre from their tips. The leaf bases are arranged in three vertical columns set about 120 degrees apart on the main stem, forming a triangular shape in cross section. This shape has given rise to the palm's common name.