Unlike most aquarium macro algae, C. taxifolia has the appearance of a vascular plant with "leaves" arranged neatly up stalks, like a fern. Behind this appearance, the plant is a typical macro alga, without the vascular system to transmit nutrients and cells that plants originally evolved on land have.
Caulerpa taxifolia has been described as storing in its "leaves" a single chemical, 'caulerpicin', that is noxious to fish and other would-be predators, though not toxic to the water around it. This is in contrast to plants which produce a variety of toxins, but in reduced amounts. On the other hand, studies have found that there is reduced pollution and toxicity in waters where it grows invasively, as around port cities in the Mediterranean. Original concerns about it reducing biodiversity of fauna have also been allayed, as species counts have shown this remains about the same.