Nitella Agardh: Characeae (stonewort family). Stoneworts. Species vary in height from a few inches to over 3 ft (90 cm), and grow in shallow to deep water attached to the substrate. These bright green algae have a growth habit similar to an aquatic plant, with a slender upright stalk and whorls of linear structures that superficially resemble thin leaves or branches. In Nitella, unlike Chara, these branchlets can divide or branch again. Emerging downward from the branchlet whorl is another circle of shorter structures, resembling stipules. None of these structures have spines and the Nitella species do not feel rough; nor do they have the garlic odor or calcium deposits of Chara. These algae form stands or lawns that seldom reach nuisance status.