Iris lactea is a species in the genus Iris, it is also in the subgenus of Limniris. It is also in the Iris series Ensatae, it is the only species in the series, Iris Ensate is actually in Iris series Laevigatae. It is a rhizomatous perennial.
It is commonly known in the UK as the 'White Flowered Iris' or in the US as 'Milky Iris'.
In Ladakhi of Tibet, it is known as 'Tesmamentok'. Meaning pale purple flower. Note, 'Lactea' is botanical Latin for milky color. Hence, common name of 'Milky Iris'. In China, it is written as bai hua ma lin It also known as Ma Lin or Malan flower.
It was first published by Pallas in 'Reise Russ. Reich' (Reise durch Verschiedene Provinzen des Russischen Reichs - translated as 'Travel through various provinces of the Russian Empire') in 1776.
The taxonomy of this species has been very confused. It was originally named Iris ensata lactea (Thunberg) in Transactions of the Linnean Society of London (page 328) on 1 May 1794 but later Iris ensata was re-classified as Iris kaempferi. Which is now a synonym of Iris ensata (within Iris series Laevigatae). Even Dykes in his books 'Iris Genus'(1913) and 'Handbook of Iris'(19 ) got the name incorrect and recorded it as 'Iris ensata'. Later, writers have tried to rectify the mistake. Fritz Kohlein in his book 'Iris'(1987) called it 'Iris ensata auct. non Thunberg.'
Many new names were considered but finding out which name was first used and should have precedence has been difficult. So it has generally been left as Iris lactea(Pallas).
Iris lactea is an accepted name by the RHS.
It is hardy to USDA Zones 3-9.
In 2008, a study was carried out on the anatomical structure of the leaf and drought resistance of 4 different species of Iris (Iris songarica, Iris potaninii, Iris loczyi and Iris lactea) from Qinghai, China. It showed that all the species were strongly adaptable to drought conditions.
As most irises are diploid, having two sets of chromosomes. This can be used to identify hybrids and classification of groupings. It has a chromosome count: 2n=40, 44, 50.
It is widely grown throughout China, where it is often used as an ingredient in a herbal contraceptive. It has also been used in anti-cancer drug 'Irisquinone', which comes from a herbal remedy. The rhizomes are also used in traditional oriental medicine, including Tibet. The flowers and seeds can also be used in medicines. The dried flowers can by used an ingredient to remedy diuretic laxative. The seeds are used to treat many ailments including; fever, jaundice, menorrhagia, heat pain, nausea, sore throats, vomiting, urination, carbuncles and boil problems.
The leaves are used as fodder for animals, and for thatching, matting and basket work, and its leaf fibres are also used in paper making and for brushes. The flowers contain the pigment - anthocyanin.
It has also been used in veterinary medicine. The consumption of the flowers and seeds is thought to increase a cow's milk yield.
Since Iris lactea, is one of the most common wild irises across all of China, living it a diverse range of habitats. It is very tolerant of most garden conditions. It is very tolerant plant, growing in a variety of soils (including those that dry out in summer), salty areas and can be used as a soil improver. Such as being cultivated on slopes (to conserve water|), on high salty soils (to remove the salt) and desertification control. It prefers sunny places, but can grow successfully in shady places. It has a strong resistance to water logging, salinity, trampling, poor, pest and disease.
It has been planted in mass on high leaded soils to reduce the lead contamination.
It is suitable for cultivation in rock gardens and group planting.
It can be propagated by seed and by division.
Iris lactea has a thick creeping rhizome, that is covered in reddish purple fibres.
It grows to a height of between, 3–50 cm (1–18 in). With a 10–30 cm (4–12 in) flowering stem.
It has 2-4 flowers per stem, blooming between April and June, or May and August in the UK. The violet scented flowers, can last for 2–3 weeks and measure about 5–7.5 cm in diameter.
It has lanceolate (lance-shaped), green spathes, masuring 4.5-10 x 0.8-1.6 cm.
The flowers come in a range of shades from pale blue to violet, white or yellow. It has dark standards, delicate white falls, which are striated with blue, red-purple or violet.
It has flower stalks (pedicel) measure about 4–7 cm long, with a very short perianth tube (3 mm), 2.5–3.2 cm stamens and yellow anthers.
The leaves are linear, mostly ribbed, greyish green, rising from the base of the plant. They are between 14–70 cm long and between 3-7mm wide.
It fruits (makes seeds) between June and September (after flowering), the seed capsule is narrow and cylindric in shape, with 6 ribs running along the side of the capsule, which ends in a beak-like point. The capsule measures 6.5–7.5 × 1–1.4 cm. The fruiting stems are unequal, ranging from 4–10 cm. Inside the capsule, are maroon-brown seeds which are pyriform.