Thalassia

Banks & Solander ex K. D. König

Annals of Botany 2: 96. 1805.

Common names: Turtle-grass
Etymology: Greek thalass, sea
Treatment appears in FNA Volume 22.

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.

Distribution

North America, Central America, Africa, Asia, Australia.

Discussion

Species 2 (1 in flora).