Several species of Laurencia have been described from the tropical, subtropical and temperate regions of the world. Many of the species in the tropics make up a large component of the algal biomass in intertidal habitats. In Hawaii, the subtidal flora has not been extensively surveyed, and therfore probably consists of many yet undiscovered species. It is evident that Laurencia has many species in Hawaii and more taxonomic and systematic attention should be given to it in the future. The axis is either compressed and flattened or round and terete.
Plants can range in size from less than a millimeter to several centimeters in height.
Rudimentary colorless trichoblasts often protrude from this apical pit region. Lateral growth of the main axis occurs when cells from the main central axial filament begin to divide laterally, first producing a ring of five pericentral cells, and these later dividing to produce the outer layer of small pigmented cortical cells. In mature axes this growth pattern is obscured and actually quite unrecognizable. Adult axis structure is composed of a parencymatous matrix, with an obscure polysiphonous core, surrounded by a cortex of isodiametric cells, these sometimes with lenticular thickenings. The tetrasporangia are tetrahedrally divided and scattered in the outermost cortical layer of the branchlets.