Hydroleaceae

Abstract

Perennial, rarely annual, herbs or small shrubs, often semi-aquatic, erect, prostrate or decumbent, stems succulent or woody, often with aerenchyma in the primary cortex, glabrous to hispid, glandular trichomes present or not, 1–2 axillary thorns per node, or thorns absent. Leaves alternate, sessile or petiolate, exstipulate, blade linear to ovate, apex acuminate to rounded, base attenuate to cordate, margin entire or serrulate, glabrous to glandular-pubescent. Inflorescence terminal or axillary, cymose or racemose, rarely flowers solitary. Flowers bisexual, actinomorphic or slightly zygomorphic; sepals 5, nearly free to base, usually lanceolate, persistent, glabrous, puberulent or glandular-pubescent; petals 5, imbricate, united at base, blue or white, corolla rotate or campanulate; stamens 5, filaments white or blue, adnate to corolla tube, usually conspicuously dilated at base, anthers sagittate, basifixed; nectary disk absent or present; ovary superior, globose to ellipsoid, oblique to median flower plane, usually 2-locular, ovules very numerous, placentation parietal at the apex, otherwise axillary with enlarged, sometimes bilobed placentas; stylodia 2(−5), free, spreading, persistent, stigma slightly funnelform or capitate, papillose. Capsule with loculicidal, septicidal, or irregular dehiscence, globular to cylindrical. Seeds numerous, ovoid to cylindrical, symmetrical or occasionally asymmetrical, usually with longitudinal ridges. n = 9, 10, 12; 2n = 18, 24, 20, 40.