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Iris humilis
Iris humilis is a plant species in the genus Iris. It is also in the subgenus of Iris and in the Psammiris section. It is a rhizomatous perennial, with a wide distribution range from Europe to Russia to China, via Mongolia and Kazakhstan. It has sword-shaped leaves, a short stem and yellow flowers with an orange beard. It is cultivated as an ornamental plant in temperate regions. It once had Iris arenaria as a synonym or as a subspecies. It is a yellow dwarf iris only from central Europe. In some sources it is still listed as a subspecies of Iris humilis. DescriptionIris humilis is very similar in form to Iris mandshurica (another Psammiris species), which leaves curve to one side, but it is a shorter plant.[2] It has thick creeping rhizome,[3][4][5] which is branched,[4] and about 1 cm in diameter.[6] The rhizome has the remains of last seasons leaves on the top.[2] It has bluish-green,[2][4] gray-green,[7][8] or light glaucous green,[9][10] sword shaped or lanceolate,[3] basal leaves.[6][7] They can grow up to 5–10 cm (2–4 in) long,[8][9][10] and 0.2–0.7 cm wide,[9][11][12] They have incurving tips,[9][12] and they disappear in summer, after flowering.[10] It has a simple dwarf (or short stem),[13][14] that can grow up to between 5–25 cm (2–10 in) tall.[15][16][17] The stems have 2–3 spathes (leaves of the flower bud), which are lanceolate and are (scarious) membranous at the top of the leaf.[4][9] They have short,[4] 7.5mm long pedicels (flower stalks).[9] The stems hold between 1 and 3 flowers,[18][19][11] in late spring,[4][12][14] between April and June.[9][13][19] The flowers only last for a day,[19] but they sometimes repeat the display.[13] The vanilla scented,[19] flowers are 3–4 cm (1–2 in) in diameter,[10][12][19] come in shades of yellow,[17][19][20] including bright yellow.[9][16][18] The flower buds are normally green, that have a slight tinge of bronze.[9] It has 2 pairs of petals, 3 large sepals (outer petals), known as the 'falls' and 3 inner, smaller petals (or tepals), known as the 'standards'.[6][21] The falls are oblong shaped, and 35 mm (1 in) long and 1.2 cm wide.[9] They are veined brown or purple brown.[7][10][20] They have a central orange beard.[12][15][18] The shorter,[9][11] standards are 30 mm (1 in) long and 0.3 cm wide.[9] The standards are not erect and this gives the flower a flattish appearance.[11] It has a 1 cm long ovary and a 0.5 cm long, funnel shaped perianth tube.[9] It has styles that are shorter than the petals,[11] about 2.5 cm long, which have short narrow crests.[9] The anthers are cream with green-black edging and the pollen is greenish coloured.[9] After the iris has flowered, in August,[4] it produces an elliptical seed capsule,[2] which is about 3 cm long.[9] The capsules dehisce (split open), below the apex.[9] Inside the capsules, are wrinkled, light brown,[2] or brown,[4] pyriform (pear-shaped) seeds.[9] They have flat creamy-white aril (or appendage).[9] GeneticsAs most irises are diploid, having two sets of chromosomes, this can be used to identify hybrids and classification of groupings.[21] It is normally published as 2n=22.[10][11][17] There has been several counts, over the years including 2n=27, Krogulevich 1978, 2n-24, Sokolovskya & Probatova, 1986, 2n=28, Starobudtsev & Mironova, 1990, 2n=28, Malakhova, 1990, 2n=28 Malakhova & Markova, 1994. As Iris flavissima 2n=22, Doronkin.[15] This shows two separate entities.[15] Since Iris arenaria has a count of 2n=22,[22] this means that Iris flavissima is a synonym of Iris arenaria and 2n=27 or 2n=28 are the true counts of Iris humilis. Taxonomy_IMG_8480.JPG) It is pronounced as (Iris) EYE-ris (humilis) HEW-mil-is.[16] It has the common name of sand iris.[7][16][23] Although this name normally refers to Iris arenaria, which was formerly once thought to be a subspecies of Iris humilis, it is now a separate species in its own right.[22] Iris humilis is also known as low iris,[2][24] and yellow iris.[3][13][24] Note, that Iris pseudacorus is also commonly known as the 'yellow flag' or 'yellow iris' as well. It is known as Sand-Schwertlilie (meaning sand iris) in Germany.[25] The Latin specific epithet humilis refers to low growing or dwarfish.[8][26] It was first published and described by Johann Gottlieb Georgi in 'Bemerkungen einer Reise im Russischen Reich' (Bemerk. Reise Russ. Reich) Vol.1 page196 in 1775.[23][27][28] Georgi described from specimen plants from near to Lake Baikal, (it was called originally Iris flavissima).[28] This is now classified as a synonym of Iris humilis.[1] It was also published by Karl H. Ugrinsky in 'Fedde's Report. Spec. Nov., Beihefte' Vol.14 in 1922.[15] In 1808, Bieberstein called a plant (from the Caucasus mountains) Iris humilis, in 'Fl. Taur.-Caucas' Vol.1 on page 33. It was later changed (due to Georgi's earlier publishing) and re-classified as a synonym of Iris pontica Zapal.[15] It was verified by United States Department of Agriculture and the Agricultural Research Service on 4 April 2003, then updated 2 December 2004.[23] It is an accepted name by the RHS.[29] Distribution and habitatIt is native to a wide distribution area, including temperate regions of Asia and Europe.[6][10][23] RangeIt is found in Europe,[19][20] within the countries of Austria,[9][10][11] Czechoslovakia,[10][11] Hungary,[10][11][18] and Romania.[10][11][23] However, some or most of these plants could be Iris arenaria, which also has a distribution area in central and eastern Europe. It is found within the Siberian region,[17][18][23] of the Russian Federation,[13][17][20] in the states of Buryatia, Chita, Irkutsk, Magadan, Primorye and Tuva.[23] It is also found in Kazakhstan (formerly part of Russia).[23] Within Asia, it found in China,[4][5][29] within the Chinese provinces, of Heilongjiang, Jilin, Nei Monggol, Ningxia and Xinjiang,[23] It is also found in Mongolia,[13][17][23] and Japan.[2][4][29] It is listed with Iris glaucescens, Iris lactea, Iris ruthenica, Iris sibirica, Iris tenuifolia and Iris tigridia being found in the Altai-Sayan region (where Russia, China, Mongolia and Kazakhstan come together).[30] HabitatIt grows in calcareous sandy and stony (or rocky) areas,[7][9] including (mountain and hill) slopes,[5][6] meadows,[5][6] steppes,[3][5] and on the edges of birch forests,[3][5] or pine forests,[2] and beside river banks.[3] They can be found at an altitude of 200–1,500 ft (61–457 m) above sea level.[9] ConservationThe iris is rare in various regions,[5][7][11] especially in European Russia and Ukraine.[11] It is listed in the Red Book of Omsk and Tyumen regions (of Siberia).[2][4][5] Many populations of Iris humilis exist in protected reserves including, Azas, Baikal-Lensky, Baikal, Barguzinsky, Sokhondinsky and Ubsunur.[2][5] CultivationIt is hardy to between USDA Zone 1 and Zone 6.[11][16] It survives in Siberia, so is cold resistant.[2] It prefers to grow in well-drained soils,[8][18] it prefers soils containing sand.[7][19] It can tolerate mildly acidic or mildly alkaline soils (PH levels between 6.1 and 7.8),[16] including those with lime.[19] It can tolerate positions in full sun or partial shade.[16][19] It has average water needs during the growing season,[16] The leaves can be damaged by rust fungi.[4] It can be grown in rock gardens,[2][8] including rock screes,[18] but needs plenty of space.[9] It is rarely grown in the UK.[14] To grow in the UK, William Rickatson Dykes recommends to plant the iris, on a 5 cm layer of sand, over garden soil with added leaf mould (or compost).[9] In 1812, it was grown in gardens near Moscow.[28] It was then tested at botanic gardens in St. Petersburg, Barnaul, Novosibirsk and Chita.[2] PropagationIt can be propagated by division (of the rhizome), or by seed growing.[9][16] In the wild, some habitats generate poor seed and vegetative propagation.[4] The plant needs to be hand pollinated (in the UK) to create seed.[9] Seeds are collected from the dry pods/capsules, when the seeds are ripe.[16] Seeds need cold stratification, to germinate. They germinate very slowly. In the lab, seeds do not exceed a germination rate of 30%.[4] Seeds should be sown in trays, in a cold frame or unheated greenhouse.[16] Germinated seedlings, can produce flowers in the second year of growth.[9] Hybrids and cultivarsIris humilis cultivars include; 'Borzeana', 'Dahurica', 'Flavissima', 'Flavissima Orientalis', 'Flavissima Phylospatha', 'Stolonifera' 'Transuralensis' and 'Umbrosa'.[15] ToxicityLike many other irises, most parts of the plant are poisonous (rhizome and leaves), if mistakenly ingested can cause stomach pains and vomiting. Also handling the plant may cause a skin irritation or an allergic reaction.[16] Traditional medicineThe rhizomes can be used as part of a Tibetan herbal medicine to regulate menstruation. A powdered form of the rhizome can be used for sepsis and infections.[3] References
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