NAJADACEAE,  Water-nymph Family

Subme rsed aquatics; monoecious or dioecious; stems slender, branching; leaves linear. base wider and sheathing; flowers monosporaogiate, minute, axillary; staminate flower a single stamen; carpellate flower 1 carpel with 1 style, 2-4 stigmas, and 1 ovule; markings on fruit visible through thin involucre. Many features used in key are visible only when magnified.