Ulmus gaussenii | |
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Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Clade: | Rosids |
Order: | Rosales |
Family: | Ulmaceae |
Genus: | Ulmus |
Species: | U. gaussenii |
Binomial name | |
Ulmus gaussenii | |
Ulmus gausseniiW. C. Cheng, the Anhui, or hairy, elm, is a medium size deciduous tree whose natural range is restricted to the valleys of the Langya limestone mountains of Chu Xian [2] in Anhui Province, eastern China. [3] The tree was most commonly found on the flood plains, indicating a tolerance of periodic inundation. However, U. gaussenii is now possibly the rarest and most endangered elm species, with only approximately 30 trees known to survive in the wild in 2009. [4]
The tree was introduced to the West in 1995, at the Morton Arboretum, Illinois, as part of an evaluation of Chinese elms for landscape use. [5] However, closer examination of the leaves at the Morton suggests that their trees are in fact Ulmus castaneifolia . [6]
The tree can grow to a height of about 25 m, with a slender trunk < 0.8 m d.b.h. The bark is longitudinally fissured and almost black. The leaves are generally obovate, < 11 cm long, borne on densely pubescent reddish twigs, sometimes featuring flat corky wings. The wind-pollinated apetalous flowers appear in March, the large orbicular samarae < 28 mm in diameter ripen in April. [7] [8]
The tree is resistant to Dutch elm disease and the elm leaf beetle Xanthogaleruca luteola . [9]
The species is cultivated in Jiangsu (Nanjing), [8] but remains very rare in cultivation in the West. In artificial freezing tests at the Morton Arboretum the LT50 (temp. at which 50% of tissues die) was found to be -30.7 °C. [10] The Anhui elm was considered of particular interest, as its riparian habitat suggests it tolerates anoxic ground during prolonged flooding. [11] Very few specimens are cultivated (2019) in Europe, notably in the UK and the Netherlands. There are no known cultivars of this taxon, nor is it known to be in commerce.
The tree was named in 1939 for Marcel-Henri Gaussen (1891–1981), a French botanist who travelled widely in Asia. [12]
Ulmus davidiana var. japonica, the Japanese elm, is one of the larger and more graceful Asiatic elms, endemic to much of continental northeast Asia and Japan, where it grows in swamp forest on young alluvial soils, although much of this habitat has now been lost to intensive rice cultivation.
Ulmus bergmannianaC.K.Schneid., commonly known as Bergmann's elm, is a deciduous tree found across much of China in forests at elevations of 1500–3000 m.
Ulmus castaneifoliaHemsley, the chestnut-leafed elm or multinerved elm, is a small deciduous tree found across much of China in broadleaved forests at elevations of 500–1,600 metres (1,600–5,200 ft).
Ulmus laciniata(Trautv.) Mayr, known variously as the Manchurian, cut-leaf, or lobed elm, is a deciduous tree native to the humid ravine forests of Japan, Korea, northern China, eastern Siberia and Sakhalin, growing alongside Cercidiphyllum japonicum, Aesculus turbinata, and Pterocarya rhoifolia, at elevations of 700–2200 m, though sometimes lower in more northern latitudes, notably in Hokkaido.
Ulmus macrocarpaHance, the large-fruited elm, is a deciduous tree or large shrub endemic to the Far East excluding Japan. It is notable for its tolerance of drought and extreme cold and is the predominant vegetation on the dunes of the Khorchin sandy lands in the Jilin province of north-eastern China, making a small tree at the base of the dunes, and a shrub at the top.
Ulmus changii, occasionally known as the Hangzhou elm, is a small deciduous tree found across much of China in forests at elevations of up to 1800 m. Owing to its increasing scarcity, U. changii was added to the Hainan Province Protected Plants List in 2006.
Ulmus elongata, also known as the long raceme elm in the US, is a deciduous tree endemic to broadleaf forests in the eastern provinces of China.
Ulmus glaucescensFranch., the Gansu elm, is a small deciduous tree from the northern provinces of China, where it is found along river valleys and on mountain slopes at elevations of 2000–2600 m.
Ulmus lamellosa, commonly called the Hebei elm, is a small deciduous tree native to four Chinese provinces, Hebei, Henan, Nei Mongol, and Shanxi, to the west and south of Beijing.
Ulmus microcarpa was named and first described by the Chinese botanist L. K. Fu, who discovered the tree in the Chayu broad-leaved forests of south-eastern Xizang at altitudes of around 2800 m during the 1973 Qinghai - Tibet Expedition. Unlike the majority of Tibet, the Chayu region has a subtropical highland climate featuring warm, wet, summers and mild, dry, winters. Commonly known as the Tibetan Elm, the tree was introduced to the United States in 2006, and the UK in 2013; it remains one of the rarest species of elm in cultivation.
Ulmus prunifoliaW. C. Cheng & L. K. Fu, the cherry-leafed elm, is a deciduous tree endemic only to the province of Hubei in central eastern China, where it is found at elevations of 1000–1500 m.
Ulmus chenmouiW. C. Cheng, commonly known as the Chenmou, or Langya Mountain elm, is a small deciduous tree from the more temperate provinces of Anhui and Jiangsu in eastern China, where it is found at elevations below 200 m on the Langya Shan and Baohua Shan mountains. The tree was unknown in the West until 1979, when seeds were sent from Beijing to the De Dorschkamp research institute at Wageningen in the Netherlands.
Ulmus davidiana, also known as the David elm, or Father David elm, is a small deciduous tree widely distributed across China, Mongolia, Korea, Siberia, and Japan, where it is found in wetlands along streams at elevations of 2000–2300 m (6,500–7,500 ft). The tree was first described in 1873 from the hills north of Beijing, China.
Ulmus pseudopropinquaWang & Li, occasionally known in the United States as the Harbin spring elm, is a small deciduous tree found only in Heilongjiang, the northeasternmost province in China. The tree has not been studied comprehensively, and it has been speculated it may be a natural hybrid of Ulmus davidiana var. japonica and Ulmus macrocarpa.
Ulmus szechuanicaFang, known as the Szechuan (Sichuan), or red-fruited, elm, is a small to medium deciduous Chinese tree found along the Yangtze river through the provinces of Sichuan, Jiangxi, Anhui, and Jiangsu.
Ulmus 'Morton' is an elm cultivar cloned from a putative intraspecific hybrid planted at the Morton Arboretum in 1924, which itself originated as seed collected from a tree at the Arnold Arboretum in Massachusetts. Although this tree was originally identified as Ulmus crassifolia, it is now believed to have been a hybrid of the Japanese elm and Wilson's elm. Accolade has proven to be the most successful cultivar tested in the US National Elm Trial, averaging a survival rate of 92.5% overall.
The Japanese elm cultivar Ulmus davidianavar.japonica 'Prospector' was originally treated as a cultivar of Wilson's elm U. wilsonianaSchneid., a species sunk as Ulmus davidiana var. japonica by Fu. A U.S. National Arboretum introduction, it was selected in 1975 from a batch of 1965 seedlings in Delaware, Ohio, and released without patent restrictions in 1990. 'Prospector' proved moderately successful in the US National Elm Trial, averaging a survival rate of 76% overall.
Ulmus bergmanniana var. lasiophyllaC. K. Schneid. is endemic to China, on mountain slopes at elevations of 2100–2900 m in Gansu, Shaanxi, north-west Sichuan, south-east Xizang, and north-west Yunnan.
Ulmus parvifolia, commonly known as the Chinese elm or lacebark elm, is a species native to eastern Asia, including China, India, Japan, Korea, and Vietnam. It has been described as "one of the most splendid elms, having the poise of a graceful Nothofagus".
Ulmus 'Morfeo' is a hybrid elm cultivar raised by the Istituto per la Protezione delle Piante (IPP), Florence, in 2000. 'Morfeo' arose from a crossing of the Dutch hybrid clone '405' and the Chenmou Elm, the latter a small tree from the provinces of Anhui and Jiangsu in eastern China, The '405' clone is a full sister of 'Groeneveld', a crossing of an English U. × hollandica and a French U. minor from the Barbier Nursery, Orléans.