Malus hupehensis (Pamp.) Rehder

Description

Malus hupehensis is a tree up to 8 m tall. Its leaves are ovate, 5–10 cm long, with sharp fine teeth. The flowers, 3.5–4 cm across, are pink in bud and open white; they usually have three styles. The fruit is yellowish green flushed with red and about 1 cm across. In China it flowers in April and May and fruits in August and September¹. The flowers are fragrant and the leaves leathery, and it is very close to the Siberian crab apple, from which it differs in its triangular rather than lance-shaped sepals, pink buds and usually three rather than five styles².

Range and habitat

It grows on slopes and in thickets in valleys, from sea level to 2,900 m, across central, eastern and southern China, from Shanxi, Shandong and Gansu to Guangdong and Fujian¹. The IUCN Red List assessed it in 2014 as Least Concern, with a stable population⁴. It has been introduced to North America and elsewhere^3,5.

Seeds without fertilisation

This is the apple best known for apomixis: it forms seeds whose embryos come from the mother plant’s own tissue, so that its seedlings are clones of their parent. In apples pollination is still needed for seeds to form, and apomixis goes with polyploidy⁶. Plants with 51 and 68 chromosomes have been counted^1,3. At least some clones are apomictic triploids, but diploids have also been reported. One clone, named after Yichang, has been collected at least three times in central China at sites hundreds of kilometres apart, and the species may be an aggregate of several triploid microspecies and perhaps sexual diploids².

Uses and history

In Hubei and Sichuan it is used as a rootstock for apples, its young leaves are made into a substitute for tea, and its spring flowers and abundant autumn fruit make it an ornamental tree¹. Alfred Rehder described it as Malus theifera, after the tea-like drink, from Ernest Wilson’s collections made around Yichang in western Hubei from 1900; Wilson thought it the finest deciduous flowering tree he had introduced. Rehder later found that Renato Pampanini had already described it as Pyrus hupehensis, and in 1933 he made the combination Malus hupehensis².

Where the sources disagree

• Ploidy. The Flora of China and the Flora of North America record 51 and 68 chromosomes^1,3; Trees and Shrubs Online reports that some studies have found diploids too².
• Taiwan. The IUCN Red List includes Taiwan in its native range⁴; Plants of the World Online lists it as introduced there⁵.
• How threatened. The IUCN Red List assessed it in 2014 as Least Concern⁴, but a 2015 review counted it among the endangered apples on the IUCN list of 2013⁷.