Iris lactea Seeds | Chinese Iris
LATIN NAME: Iris lactea
COMMON NAME: Chinese Iris
Plant Profile
Iris lactea is a tough, rhizomatous bearded iris of the dry grasslands of Central Asia, Mongolia, Siberia and northern China, where it grows in saline and alkaline soils that few other plants tolerate. It makes dense fans of narrow, grey-green leaves about forty centimetres long, and in May and June carries two or three pale lilac to white flowers on each stem, faintly veined and bearded on the falls.
The plant spreads by a woody rhizome just below the surface, and old clumps form a solid mat. It is one of the few irises that will grow in pure sand or on the edge of a salt pan. The Chinese name, ma lin, refers to the fibre in the leaves, which has been twisted into rope for longer than there are records of the plant in cultivation.
Science & Biotechnology
Iris lactea is placed in the subgenus Limniris, the beardless irises, though its falls carry a low ridge that suggests the bearded group; the classification of the genus has been revised repeatedly and the position of this species has moved with it. The variety chinensis, which is the form usually grown, differs in being more robust and in having slightly larger flowers.
The plant is a halophyte: it tolerates soil pH above 9 and salt concentrations that would kill most irises, and studies of its roots have found organic acids that chelate sodium and keep it away from the growing tissue. That physiology is why it is used in the revegetation of salt-affected farmland in Inner Mongolia and Gansu. The seed capsule is large and angular, and the seed is flattened and brown.
Uses & Benefits
In China the plant is used for two practical purposes. The leaves yield a strong fibre that has been twisted into rope, brooms and paper, and the roots are gathered as a source of a coarse brush fibre. It is also planted to stabilise dunes and to reclaim saline ground, since its mat of rhizomes holds the surface and its tolerance of salt lets it establish where crops will not.
In gardens it is grown in dry, sunny places, on a bank or in a gravel garden, where its grey leaves and pale flowers suit a restrained planting. The rhizome has a place in Chinese medicine as ma lin, used as a diuretic and astringent, but the fresh rhizome is irritant and the dried one is a professional preparation, not a garden remedy.
Growing from Seed
Iris seed has a hard coat and a dormant embryo, and it germinates best if sown fresh in late summer. Soak the seed for 24 hours, then sow in a gritty mix and leave the pan outside through winter; germination comes the following spring, and some seed will wait a second year. Do not dry the seed out once it has been harvested, because the embryo dies.
Prick the seedlings out into deep pots, since the root goes down before the leaves appear, and grow them on in full sun. Plant out in late summer, setting the rhizome just at the surface in poor, free-draining soil, and water only until they are established. The species resents rich soil and wet winter ground, both of which rot the rhizome; a gravel mulch around the plant helps more than anything else.
Our Take
An iris for the driest, poorest, most alkaline corner of the garden, and a useful plant for holding sandy ground.
Related Reading
If Chinese Iris appeals to you, these related plants are worth a look: