Iris rossii


Iris rossii, the long-tail iris, is a beardless iris in the genus Iris, in the subgenus Limniris and in the series Chinenses of the genus. It is a rhizomatous herbaceous perennial from Japan, Korea and China. It has narrow, grass-like leaves, short stems and 1 or 2 purple-violet flowers.

Description

Iris rossii is similar in form to Iris ruthenica.
It has slender, tough, reddish-brown, creeping rhizomes. Under the rhizome, are long secondary roots growing into the soil, looking for nutrients and water.
They have the yellow-brown remnants of the previous seasons leaves, at the base of new leaves.
It has narrow, linear leaves, acuminate, that are between long and wide. They have between 2–4 veins. They then elongate after flowering, up to long.
It has dwarf, short stems, between long. The stem has 2 or 3 lanceolate between long and wide, spathes.
It has one or two terminal flower, in spring to early summer, between April, and May.
The small flowers are in diameter, and come in a range of shades of purple and violet, but there are occasionally white forms as well. The white form is only found in Korea.
It has two pairs of petals, three large sepals, known as the "falls", and three inner, smaller petals.
After the iris has flowered, it produces a globose seed capsule between June and August.

Biochemistry

In 2012, it was studied by isolating flavonoids including an anthocyanin and C-glycosylflavones, and xanthones from the flowers and leaves. After the study, a specimen of Iris rossii was given to the herbarium of the National Museum of Nature and Science, Japan
As most irises are diploid, having two sets of chromosomes. This can be used to identify hybrids and classification of groupings.
It has been counted several times, 2n=32, Kurita, 1940, and 2n=34, Lee, 1970.

Taxonomy

Iris rossii is pronounced as EYE-ris ROSS-ee-eye.
It is written as 小鸢尾 in Chinese script and known as xiao yuan wei in China. In Korean script, it is written as 각시붓꽃. It is known as Ehime ayame in Japan, and written as えひめあやめin Japanese script.
It has the common name of Long-tail Iris in China and Korea.
The Latin specific epithet rossii refers to John Ross, a Protestant missionary from Scotland, who lived in north-east China. John Gilbert Baker named the iris in his honour. After he had collected several specimens of the iris and sent them to Mr Baker. It was an inhabitant of dry sloping banks in the province of Sching-king, in Northern China, where it was gathered in flower on 27 April 1876.
It was then first published and described by Baker in 'The Gardeners' Chronicle' Vol.8 page 809 on 29 December 1877. It was later published in 'Gartenflora' Vol.27 page 382 in 1878, 'La Belg. Hort.' Vol.28 page89 in 1878 and the 'Journal of the Linnean Society of London' Vol.17 p387 in 1880.
It was verified by United States Department of Agriculture Agricultural Research Service on 4 April 2003.

Native

Iris rossii is native to temperate areas of Asia.

Range

It is found in Japan, Korea and China.
From the notes of Isabella Bird Bishop on 29 April 1894, she explored the valley either side of the River Han in Korea. She found various plants and flora, including; Acanthopanax ricinifolia, Rhus vernicifera, Actinida pueraria and Iris rossii.
Originally, Iris rossii was thought to be only found in the Chinese north-eastern part, of the Korean Peninsula, but it was discovered first in Hojo within Ehime Prefecture in Japan. It was then found in other regions of Japan including; the prefectures of Saga, Oita, Miyazaki, Yamaguchi, Hiroshima and Okayama. It was also found in the woodland of Nutanishi-chō, Mihara, Hiroshima.

Habitat

It grows in meadows at forest margins, on sunny hillsides. and clearings within pine woods.
At altitudes of 100m above sea level.

Conservation

Between June and November 1990, the flora of vascular plants and vegetation were studied in the protected area of Hofu City within Yamaguchi Prefecture, Japan, it was classified as Vulnerable as well as Calanthe discolor.
In 1995, it was classified as Vulnerable. It had become a threatened species, due to plant hunting, changing of land use and habitat loss.
It was found within grassland under scattered pine trees, which have been used for compost, fodder and timber production.
In 2002, it was classified as Endangered in Kumamoto Prefecture in 2002.

Cultivation

Iris rossii is hardy in the US and the UK, but is rare in cultivation.
It likes to grow in well-drained and nutrient rich soils.
It prefers positions in full sun but it is shade tolerant.
It is also very drought-tolerant and could be suitable for xeriscaping.
It could be planted in alpine scree slopes and in rock gardens.

Propagation

Iris rossii does not like being propagated by division, as it takes a long time to re-grow feeding roots, after transplanting.
Therefore, propagation from the seed is preferred.
It is thought to be a zoochory plant because ants like the seeds and carry them away to new positions. Allowing the plant to form new colonies elsewhere.

Hybrids and cultivars

Iris rossii forma Alba was found in the deciduous forests of Korea, by Dr Yong No Lee and then published in the 'Korean Journal of Botany' vol.17, No1, p33-35 in 1974.
It had white flowers streaked with yellow, instead of violet, found on other forms.
But this was later declared a synonym of Iris rossii.

Toxicity

Like many other irises, most parts of the plant are poisonous or toxic, if mistakenly ingested, it can cause stomach pains and vomiting. Also handling the plant may cause a skin irritation or an allergic reaction.