Ranunculus mauiensis, a member of the buttercup family (Ranunculaceae), is an erect to weakly ascending perennial herb 5 to 20 dm (20 to 79 in) tall with fibrous roots. It has sparse, flattened hairs on its stems, and its leaves are once compound. The basal leaves are arranged in threes and the terminal leaflet is usually the largest; leaflets are toothed and are covered with hairs. Flowers are few, and occur in branched loose cymes. Yellow flowers with five small petals 4 to 5 mm (0.16 to 0.2 in) long and are glossy on the upper surface. Achenes (dry fruits) are numerous and small, 2 to 2.2 mm (0.08 to 0.09 in) long, beaked, with a slight margin. Achenes are 2 to 2.2 mm (0.08 to 0.09 in) long. Achenes are numerous in a globose head and have smooth faces.