Caulerpa taxifolia is a light green macoalga with upright leaf-like fronds arising from creeping stolons that can attain a length of up to 2.8 m. The fronds are flattened laterally and the small side branchlets are constricted at the base (where they attach to the midrib of each frond), are opposite in their attachment to the midrib (as opposed to alternating) and curve upwards and narrow towards the tip. Frond diameter is 6-8 mm and frond length is usually 3-15 cm in the shallows, but can reach 40-60 cm in deeper situations. While the invasive aquarium strain is morphologically identical to Australian native tropical populations of this species where the shape and size of fronds are concerned, it frequently produces a much greater density of stolons and fronds.