Commelina 鴨跖草屬
型態特徵
Annual or perennial andromonoecious herbs. Stems branched, prostrate at base, erect above, rooting at nodes. Leaves sessile to subpetiolate, lanceolate or ovate; sheath cylindrical, margins pilose. Prophyll apex acuminate. Inflorescences terminal and leaf-opposed, composed of 1 or 2 cincinni enclosed in a spathe-like bract; spathe infundibuliform, or cordate and folded; bracteoles lacking. Flowers zygomorphic; sepals 3, greenish, persistent, elliptic, concave, unequal, anticous two elliptic, posticous one lanceolate; petals 3, free, blue to indigo, rarely white, unequal, lateral petals planar, clawed; fertile stamens 3, anticous, dimorphic; filaments glabrous; staminodes 2 or 3, posticous, all alike, antherodes cruciate; ovary ellipsoid-globoid, glabrous; Capsules bilocular or trilocular, valves subequal, dorsal locule usually indehiscent. Seeds 1 or 2 per locule, brown or black, deltoid or ellipsoid, dorsiventral, ventral surface planar, dorsal convex, with farinose granules, embryostega lateral, hilum linear.
About 170 species in tropical and subtropical regions; five species in Taiwan.
