Coontail can be described as:

Coontail, scientifically known as Ceratophyllum demersum, is a submerged aquatic plant that is notable for its distinct morphology. The correct description emphasizes that coontail features twisted leaves that are arranged in whorls, with a denser crown at the tips of the stems. This twisting arrangement allows for effective light capture and limits the amount of resistance it faces from water currents, making it well-adapted to its aquatic environment.

Unlike flowering plants, coontail does not produce large or conspicuous flowers, ruling out the option that describes such characteristics. Additionally, coontail is not limited to surface dwelling; it grows submerged and can often be found at various depths in a water body, contrasting with the option about being a surface-dwelling plant only. The leaves of coontail are also not broad and flat, as described in another choice, but are rather narrow and feathery, which contributes to its identification. Thus, the unique leaf structure with twisted formations and dense crowns is what accurately characterizes coontail.