Monterey Bay Aquarium Research Institute
Marine Botany

Ulva title imageMorphology   



Cross section of distromatic Ulva

Ulva species have thalli with expanded blades two cells thick (distromatic). Ulva are parenchymatous: cell division may occur anywhere on the thallus but always in a plane perpendicular to the thallus surface. Compared to more advanced algae and vascular plants, their construction is relatively simple. They do not differentiate into tissue layers or show much specialization among cells. The cells themselves are irregularly arranged and are quadrate to slightly elongate anticlinally (perpendicular to the surface), depending on the species. The cell walls are fibrillar and made up of cellulose. They store energy as starch. Arranged in sheets only two cells thick, Ulva's large surface to volume ratio allows it to have a high nutrient uptake. more morphology