The World of Apples

Wild apples

Malus baccata (L.) Borkh.

Siberian crabapple; Siberian crab

Description

Malus baccata is a tree of 10 to 14 m with arching or drooping branches. Its leaves are elliptic or ovate, 3–8 cm long, and hairless or nearly so. The white flowers are 3–3.5 cm across and the fruit, red or yellow, is only 8–10 mm across; the sepals fall before it ripens. In China it flowers from April to June and its fruit ripens in September and October. It has 34 chromosomes in its body cells1. The flowers are fragrant, the fruits pea-sized, and the species is a variable, sexually reproducing diploid2.

Range and habitat

It is a very widespread species, ranging from Siberia south into China and from Japan west along the Himalaya2. The IUCN Red List records it in Bhutan, China, India, Korea, Mongolia, Nepal and eastern Russia4, and the Flora of China adds Kashmir1. It grows in mixed forest on slopes and in thickets in valleys, from sea level to 1,500 m1. It is probably relatively tolerant of cold, though little is known about its ecology6. Its small fruit is dispersed by birds, which Robert Spengler links to its large range; seeds identified as this species have been found in high-altitude burials in the Kali Gandaki valley of Nepal7.

The IUCN Red List assessed it in 2014 as Least Concern, with a stable population4.

Uses

In northern and north-eastern China it is commonly used as a rootstock for orchard apples and for Malus asiatica1, and in North America it is also used as a rootstock and is considered a possible source of disease resistance and hardiness for breeders3. It is notably disease resistant and very hardy to cold, and its genome is rich in genes linked to defence against pathogens and to cold tolerance2.

Linnaeus described it as Pyrus baccata in 1767, probably from Russian material, making it the first of the East Asian crab apples to be named; it was moved to Malus in 1803 and reached Kew from Siberia in 1784. Trees believed to have been planted by Linnaeus at Hammarby in Sweden are still alive2. It is grown for its flowers and fruit, and sometimes escapes from cultivation3. It is a parent of the ornamental hybrids Malus × floribunda and Malus × robusta2.

Relationship to the cultivated apple

The Siberian crab apple is one of the four wild apples that the cultivated apple met on its way along the Silk Road6. In a genome study of 2017 it stood out as a genetically uniform species that has given rise to hybrids, and Malus asiatica and Malus prunifolia, the soft apples of China, appear to be crosses between it and the Asian wild apple8. It has also entered some modern orchard apples, partly through breeding for resistance to scab11.

Where the sources disagree

  • How many species. The Flora of China treats the Manchurian crab apple as a separate species, Malus mandshurica9; Plants of the World Online and the 2022 revision reduce it to a variety of M. baccata5,10. Trees and Shrubs Online calls the varieties poorly defined2.
  • Its range. Plants of the World Online includes Japan, Kazakhstan, Pakistan and Myanmar5; the IUCN Red List lists none of these4.
  • Its share in the orchard apple. Spengler counts the Siberian crab apple among the species hybridised into the orchard apple7; Cornille and colleagues note that it had hardly been studied6.

Varieties of this species in the atlas

  • Dolgo

    A Siberian crab brought from Russia to South Dakota in 1897 and introduced in 1917 for its ruby-red jelly

    Russia, 1897

Sources

  1. Malus baccata, Flora of China vol. 9, Gu Cuizhi and Stephen A. Spongberg, Flora of China, eFloras.org, 2003. Supports: the description (tree 10–14 m with arching or pendulous branches, leaves 3–8 cm, flowers 3–3.5 cm, petals white, pome red or yellow, 8–10 mm, sepals falling, flowering April–June and fruiting September–October, 2n = 34); mixed forests and valley thickets from sea level to 1,500 m in the provinces listed, and in Bhutan, India, Kashmir, Korea, Mongolia, Nepal and Siberia; grown as an ornamental and "commonly used as stock to graft Malus pumila and M. asiatica in N and NE China".
  2. Malus baccata, Julian Sutton and Nick Dunn, Trees and Shrubs Online (International Dendrology Society), 2021. Supports: fragrant flowers and pea-sized fruit; range from Siberia to southern China and from Japan to the Himalaya; a variable sexual diploid at the centre of a difficult group of small-fruited East Asian crabs; disease resistant and very cold hardy; trees believed planted by Linnaeus at Hammarby still alive; described by Linnaeus as Pyrus baccata in 1767, probably from Russian material, and moved to Malus in 1803; introduced to Kew from Siberia in 1784; parent of M. × floribunda and M. × robusta; implicated in M. asiatica and M. prunifolia; a genome rich in genes for pathogen defence and cold tolerance; growing interest in its use for rootstocks; the common name Siberian crab.
  3. Malus baccata, Flora of North America vol. 9, Elizabeth E. Dickson, Flora of North America, eFloras.org. Supports: introduced in North America, escaping from cultivation; grown for flowers and fruit; used as a rootstock and a possible source of disease resistance and cold hardiness; the common name Siberian crabapple.
  4. Malus baccata, The IUCN Red List of Threatened Species 2016: e.T50030498A50030538, L. Rhodes and N. Maxted, 2016. Supports: Least Concern, assessed 1 May 2014; population stable; native to Bhutan, China, India, North and South Korea, Mongolia, Nepal and Russia (eastern Siberia and the Far East).
  5. Malus baccata (L.) Borkh., Plants of the World Online, Royal Botanic Gardens, Kew. Supports: accepted name and authority; native range "Siberia to N. & C. Japan and Himalaya", including Japan, Kazakhstan, Pakistan and Myanmar; M. baccata var. mandshurica accepted as a variety.
  6. The domestication and evolutionary ecology of apples, Amandine Cornille and others, Trends in Genetics 30(2): 57–65; Wageningen University repository, 2014. Supports: one of the four wild apples met along the Silk Route; occurs across Siberia and South Asia, probably relatively cold-tolerant, with little known of its ecology; population structure not yet studied; fruit about 1 cm.
  7. 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: a small-fruited, bird-dispersed species whose range expanded in the Holocene; seeds identified as M. baccata from high-elevation burials in the Kali Gandaki valley, Nepal; counted among the species hybridised into the cultivated apple.
  8. Genome re-sequencing reveals the history of apple and supports a two-stage model for fruit enlargement, Naibin Duan and others, Nature Communications 8: 249, 2017. Supports: M. baccata with a homogeneous genetic background that gave rise to hybrid species; M. asiatica and M. prunifolia very likely hybrids of M. baccata and M. sieversii.
  9. Malus mandshurica, Flora of China vol. 9, Gu Cuizhi and Stephen A. Spongberg, Flora of China, eFloras.org, 2003. Supports: the Manchurian form treated as a separate species, Malus mandshurica, tree to 15 m, often used as stock for grafting apples in north-eastern China.
  10. 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: M. baccata accepted, with M. mandshurica reduced to M. baccata var. mandshurica.
  11. Malus domestica, Julian Sutton and Nick Dunn, Trees and Shrubs Online (International Dendrology Society), 2021. Supports: some recent input of M. baccata into M. domestica, partly through breeding for scab resistance.