''Juglans hopeiensis'' (), also known as Ma walnut, is a species of

walnut A walnut is the edible seed of any tree of the genus '' Juglans'' (family Juglandaceae), particularly the Persian or English walnut, '' Juglans regia''. They are accessory fruit because the outer covering of the fruit is technically an i ...

native to northern

Hebei Province Hebei is a Provinces of China, province in North China. It is China's List of Chinese administrative divisions by population, sixth-most populous province, with a population of over 75 million people. Shijiazhuang is the capital city. It bor ...

. Some scholars believe that the species is a hybrid of ''

Juglans regia ''Juglans regia'', known by various common names including the common walnut, English walnut, or Persian walnut amongst other names, is a species of walnut. It is native to Eurasia in at least southwest and central Asia and southeast Europe, ...

'' and '' Juglans mandshurica''. Currently, it is a threatened tree species. Historically, Ma walnut was originally distributed in the Northern

Taihang Mountains The Taihang Mountains () are a Chinese mountain range running down the eastern edge of the Loess Plateau in Shanxi, Henan and Hebei provinces. The range extends over from north to south and has an average elevation of ; its principal peak is ...

, so it was called Hebei walnut (河北核桃). This species is mainly distributed in some mountainous areas of

, Shanxi Province,

Beijing Beijing, Chinese postal romanization, previously romanized as Peking, is the capital city of China. With more than 22 million residents, it is the world's List of national capitals by population, most populous national capital city as well as ...

and

Tianjin Tianjin is a direct-administered municipality in North China, northern China on the shore of the Bohai Sea. It is one of the National Central City, nine national central cities, with a total population of 13,866,009 inhabitants at the time of the ...

in China.

Morphological characteristics

Ma walnut, whose scientific name is ''Juglans hopeiensis Hu'', is a plant belonging to the genus Juglans of the family

Juglandaceae The Juglandaceae are a plant family known as the walnut family. They are trees, or sometimes shrubs, in the order Fagales. Members of this family are native to the Americas, Eurasia, and Southeast Asia. The nine or ten genera in the family have ...

. The plant can reach up to 2.5

meter The metre (or meter in US spelling; symbol: m) is the base unit of length in the International System of Units (SI). Since 2019, the metre has been defined as the length of the path travelled by light in vacuum during a time interval of of ...

s high and often grow in high mountains. Its bark is gray-white with longitudinal cracks.

Discovery and Naming

In 1930, Zhou Hanfan (周汉藩) discovered this new species in Banjiegou, Xiakou Village, Changping County, Hebei Province (now part of

). Subsequently, one strain of the species was found in each of Jixian, Mentougou, and Lianhua Mountain. In 1934, the new species was first described by the Chinese

botanist Botany, also called plant science, is the branch of natural science and biology studying plants, especially Plant anatomy, their anatomy, Plant taxonomy, taxonomy, and Plant ecology, ecology. A botanist or plant scientist is a scientist who s ...

Hu Xiansu (better known as H. H. Hu) in his paper entitled ''Notulae systematicae ad Florem Sinensium V''. He originally indicated that the species was known locally as "Mahetao" (i.e. Ma walnut) and was once quite commonly cultivated, but it subsequently became less popular. In 1981, several plants of Ma walnut were found again in Bancheng District, Lishui County, Hebei Province. The name of the species was verified by AAS Systematic Botanist on October 15, 1998.

References

External links

Diarylheptanoids from the fresh pericarps of Juglans hopeiensis
''

ScienceDirect ScienceDirect is a searchable web-based bibliographic database, which provides access to full texts of scientific and medical publications of the Dutch publisher Elsevier as well of several small academic publishers. It hosts over 18 million ...

'', from '' Fitoterapia''. Retrieved December 10, 2020. {{Taxonbar, from=Q11175776 hopeiensis Trees of Asia Flora of China Fruit trees Plants described in 1934 Taxa named by Hu Xiansu