Trimezia martinicensis

yellow walking iris


Trimezia martinicensis

(Jazcq.) Herb. 1844

pronounced: try-MEE-zee-uh mah-tin-ee-KEN-siss

(Iridaceae — the iris family)


common name: yellow walking iris

Trimezia is from the Greek τρεις (treis), three, and μειζων (meizon), larger, the outer perianth segments being larger than the inner; martinicensis is botanical Latin, ‘from Martinique’. It is, in fact, native to all of the Caribbean islands. The ‘walking irises’ are so called because plantlets form along the flowering stalk; the stalk will bend to the ground, and the new plant can root and begin to grow.

This is the most common iris on Magnetic Island, especially in Picnic Bay, where it is found in many of the roadside gardens. It is a rhizomatous perennial with showy flowers. Its erect leaves are arranged in a fan pattern; they are bright green and flat, and the plant can grow up to about 60  – 90 cm in height. The flowers are bright yellow with brown spots; individual flowers last only a single day, but new flowers keep on coming. They grow on stems that are nearly cylindrical, and up to about 70 cm tall.

Yellow Walking Iris will grow either in sun or in shade. Plants growing in full sun like to have moist soil. Plants growing in shade can tolerate some dryness, but look best if irrigated through long periods of dryness, such as our island winters. The plant needs little help in spreading, but clumps can be divided if new areas are to be planted. This plant makes a good and attractive ground cover, but can also be grown in pots on a patio, or indoors if provided with plenty of light. Potted specimens will not form new plants.
The fruit is a capsule to 2 cm long, the seeds black and angled, 1.5 mm wide.

The bulb of the plant is astringent, purgative, emetic, and a potent emmenagogue. In Martinique, Guadeloupe and Trinidad, a decoction made from the bulb is used as a remedy for influenza, as well as a diuretic and an emmenagogue. In Trinidad, it is used in teas for treating decreased urine output and for treating an abnormal cessation of menstruation. In the Huehuetenango Department of Western Guatemala, it is widely used as a remedy for chills.

This is a very easy plant to grow; even those who normally kill off house plants are likely to be successful with Yellow Walking Iris in a pot or container, and it is practically impossible to go wrong with it in a tropical garden.


Information about medicinal qualities of plants, or about their use as medicines, is for interest only, and is not intended to be used as a guide for the treatment of medical conditions.


Photographs taken at Picnic Bay 2008-2011
Page last updated 24th April 2019