In the green algae parenchymatous type construction is seen in the order Ulvales. Ulva is an example of a parenchymatous green. The thallus consist of a flattened sheet of tissue two layers thick (distromatic). All the cells are identical, Photosynthetically active and capable of reproducing. Ulvaria and Monostroma are similar to Ulva in appearance except there is only one layer of cells.