 Pseudoparenchymatous refers to a filamentous alga with cells packed very close together to give an appearance of parenchymatous tissue, the latter being composed of cells which can truly divide in three dimensions, unusual among the algae.Filamentous algae are composed of cells that divide along a single plane, allowing only elongation to form filaments of one or more rows of cells.Algae that can divide in two planes can form sheet-like thalli or bodies.