Ottelia alismoides

Name and classification

Ottelia alismoides (L.) Pers.
Family Hydrocharitaceae

Common names

duck lettuce

Disseminule

seed

Description

Fruit with numerous seeds. Seeds fusiform, 1–2 mm long, 0.3–0.7 mm in diameter, with 2 faint slightly curved longitudinal ridges. Testa light brown, dull to semiglossy, faintly wrinkled, with a tuft of unicellular white hairs. Hilum inconspicuous. Embryo linear-spatulate; endosperm absent.

Distribution

widespread in South and Southeast Asia from India to the Philippines, including China, Japan, Korea, and Taiwan; south to Australia and the Solomon Islands; Africa (Egypt and Sudan); Italy; western hemisphere: Belize, Canada, United States

Habitat

slow moving or stagnant water, in small ponds and ditches, swamps, rice fields

General information

Ottelia alismoides, an annual submersed freshwater aquatic herb, up to 85 cm tall, is a weed of rice fields in Southeast Asia. Reproduction is by whole plants or seeds. The petioles and leaves of this plant are eaten as a vegetable in India and Malaysia.

seeds

seeds

seeds

seeds

seeds

seeds

A, seed; B, longitudinal section of seed showing embryo; C, transection of seed; drawing by Lynda E. Chandler

A, seed; B, longitudinal section of seed showing embryo; C, transection of seed; drawing by Lynda E. Chandler

fruit with part broken off

fruit with part broken off