The World of Apples

Wild apples

Malus orientalis Uglitzk.

Caucasian crabapple

Description

Malus orientalis is a small tree up to 10 m tall, without spines. Its leaves vary greatly in shape and are 3–8 cm long, sparsely hairy above at first and white-felted beneath. The flowers, about 4 cm across and white or pale pink, open in April and May; their sepals stay on the fruit, which is round and 2–3 cm across and ripens in Georgia from August to October1. Another account gives the fruit as 2–4 cm5. Without knowing a cultivated tree’s origin, telling it from the European crab apple, the Asian wild apple and the orchard apple is very difficult1.

Range and habitat

The Caucasian crab apple grows from Türkiye through the Caucasus, in Armenia, Azerbaijan, Georgia and southern Russia, to the mountains of northern Iran2,4, where it extends into the Hyrcanian forest1. Almost all its natural stands lie in the Irano-Anatolian and Caucasian biodiversity hotspots, with two old forest refuges, Colchis and the Hyrcanian forest, especially important4. It grows in forest glades and at forest edges, in scrub and along rivers, tolerates dry or mildly saline soils, and reaches 2,000 m in Georgia1. Little is known about its ecology5.

The IUCN Red List assessed it in 2014 as Data Deficient worldwide2, and again as Data Deficient for Europe in 20243. A study published in 2024 estimated its potential present range at 858,877 km², and projected that by 2070 this would shrink to 635,279 km² under a moderate climate scenario (RCP 4.5) or 456,795 km² under a severe one (RCP 8.5)4.

Relationship to the cultivated apple

The Caucasian crab apple is eaten, and sometimes grown, in its native range1, and it is still found in home gardens4. In Iran it has been used as a rootstock for orchard apples1. Researchers value its adaptation to varied conditions, its long-keeping fruit, its resistance to disease and its late flowering4.

Genetic studies show that it contributed to the orchard apple, though less than the European crab apple, and that genes have also flowed from cultivated apples into it5. Robert Spengler considers the strings of dried, halved apples found in a royal tomb at Ur, and apples from Kadesh Barnea in the Levant of the early first millennium BC, most likely to be this species6.

Where the sources disagree

  • Its range. Plants of the World Online extends the range west to south-western Bulgaria and east to Afghanistan7; the IUCN Red List limits it to Türkiye, the Caucasus and Iran2.
  • Its share in the orchard apple. Cornille and colleagues found its contribution smaller than the European crab apple’s5; Spengler, citing work in Iran, stresses its hybridisation with the Asian wild apple and suggests it may have been cultivated or tended in Iran before the Central Asian apple arrived6.
  • Authority. Plants of the World Online cites the name as Malus orientalis Uglitzk.7; the 2022 revision of the genus writes Uglitzk. ex Juz.8.

Sources

  1. Malus orientalis, Julian Sutton and Nick Dunn, Trees and Shrubs Online (International Dendrology Society), 2021. Supports: the description (small tree to 10 m, unarmed, leaves 3–8 cm, white-tomentose beneath, flowers about 4 cm, white or pale pink, April–May, persistent sepals, fruit 2–3 cm, August–October in Georgia); distribution in Armenia, Azerbaijan, Georgia, Iran, the Russian North Caucasus, Türkiye, and possibly Crimea; habitats (forest glades and edges, scrub, riverbanks, dry or mildly saline soils, to 2,000 m in Georgia); extending into the Hyrcanian forest of northern Iran; eaten and sometimes cultivated in its native range; used as a rootstock in Iran; hard to identify in cultivation.
  2. Malus orientalis, The IUCN Red List of Threatened Species 2016: e.T50049710A50049714, L. Rhodes and N. Maxted, 2016. Supports: Data Deficient, assessed 1 June 2014, global scope; population trend unknown; native to Armenia, Azerbaijan, Georgia, Iran, Russia (North Caucasus republics, Krasnodar, Stavropol) and Türkiye; forest habitat.
  3. Malus orientalis (Europe assessment), The IUCN Red List of Threatened Species 2026: e.T50049710A209093886, L. Rhodes, N. Maxted and C. R. Meredith, 2026. Supports: Data Deficient in Europe, assessed 6 March 2024.
  4. The potential range of west Asian apple species Malus orientalis Uglitzk. under climate change, Łukasz Walas, Shirin Alipour, Shiekh Marifatul Haq and Saud Alamri, BMC Plant Biology 24: 381, 2024. Supports: range from Turkey through the Caucasus (Armenia, Azerbaijan, Georgia, Russia) to the mountains of Iran; almost all natural stands in the Irano-Anatolian and Caucasian biodiversity hotspots, with the Colchis and Hyrcanian refugia; still grown in home gardens and its fruit widely used; adaptation to varied conditions, long-keeping fruit, disease resistance and late flowering; about 363 natural stands used in modelling; potential present range about 858,877 km², projected to shrink to 635,279 km² (RCP 4.5) or 456,795 km² (RCP 8.5) by 2070.
  5. The domestication and evolutionary ecology of apples, Amandine Cornille and others, Trends in Genetics 30(2): 57–65; Wageningen University repository, 2014. Supports: the name Caucasian crabapple; fruit 2–4 cm; occurrence in Turkey, Armenia, Georgia and south-western Russia, with little known of its ecology; three populations (most of Armenia; southern Caucasus; Russia); a lesser contribution than M. sylvestris to the cultivated apple; introgression from the cultivated apple into M. orientalis.
  6. Origins of the Apple: The Role of Megafaunal Mutualism in the Domestication of Malus and Rosaceous Trees, Robert N. Spengler, Frontiers in Plant Science 10: 617, 2019. Supports: the dried, halved apples strung together in a royal tomb at Ur, and the early first-millennium BC apples from Kadesh Barnea, as most likely M. orientalis; the emphasis by Gharghani and colleagues on hybridisation between M. sieversii and M. orientalis, which may have been cultivated or maintained in Iran before the Tian Shan apple arrived.
  7. Malus orientalis Uglitzk., Plants of the World Online, Royal Botanic Gardens, Kew. Supports: accepted name with the authority Uglitzk., published 1932; native range "SW. Bulgaria to Caucasus and Afghanistan" (Afghanistan, Bulgaria, Iran, North Caucasus, Transcaucasus, Türkiye); M. montana and M. sylvestris subsp. orientalis among the synonyms.
  8. A revision of the genus Malus Mill. (Rosaceae), Jing-chao Li, Jian-quan Liu and Xin-fen Gao, European Journal of Taxonomy 853: 1–127, 2022. Supports: the species accepted under the name Malus orientalis Uglitzk. ex Juz..