Plant of the Week 07/03/2006: Mosaic Plant (Ludwigia sedoides)

Plant of the Week 07/03/2006

Ludwigia sedoides (Bonpland) H. Hara

Photographed by: Chelsie Vandaveer
Credits: Mosaic plant photographed at Pondscapes, Inc.
Other Information: Olympus C-8080wz

Worldwide, there are 85 species of false loosestrifes or primrosewillows, genus Ludwigia. Most of the species are found within subtropical and tropical zones and usually in water or on wet soils. Primrosewillows have their own subfamily, the Jussiaeoideae, within the family of evening primroses, the Onagraceae.

The mosaic plant (Ludwigia sedoides (Bonpland) H. Hara) is native to Brazil and Venezuela. The plant was first collected by Alexander von Humboldt and Aimé (Amati) Bonpland. Bonpland (1805) noted the plant's habitat as "stagnantibus", in a pool of standing water.

The mosaic plant blooms during summer with four-petaled yellow flowers up to 5 centimeters (2 inches) in diameter. Although the flowers are showy, it is the floating rosette of diamond-shaped leaves that makes the plant a spectacular addition to a garden pond. The epithet, sedoides, means resembling a stonecrop (sedum). In bright light, the edges of the center leaves and older leaves turn red.

Besides the beautiful pattern the leaves form on the surface of water, the rosette shifts. During the day, the mosaic is fully open with gaps between the leaves. At night, the rosette contracts; the individual leaves pull together until they shingle over each other.

(Compiled from: "Ludwigia", A-Z Encyclopedia of Garden Plants, C. Brickell and JD Zuk eds., American Horticultural Society, DK Publishing, NY, 1996; W3Tropicos, Nomenclatural database, Jim Solomon, Missouri Botanical Garden; WL Wagner and PC Hoch. Onagraceae, The Evening Primrose Family website. 2005-July 2006 Smithsonian Institution; and personal observations)