9. Thalassia Banks & Solander ex K. D. König, Annals of Botany. 2: 96. 1805.
Turtle-grass [Greek thalass, sea]
Plants perennial, of marine waters. Rhizomes present; leaf-bearing branches arising from rhizomes at distances of several internodes; stolons absent. Erect stems rooted in substrate, unbranched, short. Leaves 2--6, basal, submersed, sessile; blade linear, base tapering to stem; apex obtuse; midvein without lacunae along side(s), blade uniform in color throughout; abaxial surfacely without prickles; intravaginal scales entire. Inflorescences 1-flowered to cymose, pedunculate; spathes not winged. Flowers unisexual, staminate and pistillate on different plants, submersed, short-pedicellate to nearly sessile; petals absent. Staminate flowers: filaments distinct; anthers linear; pollen embedded in gelatinous matrix, in moniliform chains. Pistillate flowers: ovary 1-locular; styles 6--8, not 2-fid. Fruits spheric, echinate, dehiscing into 6--8 irregular valves. Seeds pyriform; seed coat ephemeral.
Species 2 (1 in flora): North America, Central America, Africa, Asia, Australia.
SELECTED REFERENCES
Grey, W. F. and M. D. Moffler. 1978. Flowering of the seagrass Thalassia testudinum (Hydrocharitaceae) in the Tampa Bay, Florida area. Aquatic Bot. 5: 251--259. Moffler, M. D., M. J. Durako, and W. F. Grey. 1981. Observations on the reproductive ecology of Thalassia testudinum (Hydrocharitaceae) in Tampa Bay, Florida. Aquatic Bot. 10: 183--187. Moore, D. R. 1963. Distribution of the sea grass, Thalassia, in the United States. Bull. Mar. Sci. Gulf Caribbean 13: 329--342. Orpurt, P. R. and L. L. Boral. 1964. The flowers and seeds of Thalassia testudinum König. Bull. Mar. Sci. Gulf Caribbean 14: 296--302.
