white mulberry

Morus alba
Morus Alba
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Rosids
Order:	Rosales
Family:	Moraceae
Tribe:	Moreae
Genus:	Morus
Species:	M. alba
Binomial name
Morus alba L.

White Mulberry bearing fruit.

The white mulberry (Morus alba) is a short-lived, fast-growing, small to medium sized mulberry tree, which grows to 10–20 m tall.

The species is native to northern China, and is widely cultivated (and even naturalized) elsewhere.^[1][2] It is also known as Tuta in Sanskrit and Tuti in Marathi.

On young, vigorous shoots, the leaves may be up to 30 cm long, and deeply and intricately lobed, with the lobes rounded. On older trees, the leaves are generally 5–15 cm long, unlobed, cordate at the base and rounded to acuminate at the tip, and serrated on the margins. The leaves are usually deciduous in winter, but trees grown in tropical regions can be evergreen. The flowers are single-sex catkins, with catkins of both sexes being present on each tree; male catkins are 2–3.5 cm long, and female catkins 1–2 cm long. The fruit is 1–2.5 cm long; in the species in the wild it is deep purple, but in many cultivated plants it varies from white to pink; it is sweet but bland, unlike the more intense flavor of the red mulberry and black mulberry. The seeds are widely dispersed by birds, which eat the fruit and excrete the seeds.^[1][2][3]

Leaf variation

The white mulberry is scientifically notable for the rapid plant movement of the pollen release from its catkins. The flowers fire pollen into the air by rapidly (25 µs) releasing stored elastic energy in the stamens. The resulting movement is in excess of half the speed of sound, making it the fastest known movement in the plant kingdom.^[4]

Cultivation

Cultivation of white mulberry for silkworms began over four thousand years ago in China. 6,260 km² of land is currently devoted to the species in China.^[2]

The species is now extensively planted and widely naturalized throughout the warm temperate world. It has been grown widely from India (with 2,820 km²[2]) west through Afghanistan and Iran to southern Europe for over a thousand years for leaves to feed silkworms.^[3]

More recently, it has become widely naturalized in urban areas of eastern North America, where it hybridizes readily with a locally native red mulberry (Morus rubra). There is now serious concern for the long-term genetic viability of red mulberry because of extensive hybridization in some areas.^[5] As a result, it is listed as an invasive plant in parts of North America.^[6]

Uses

Fruitless mulberry trees

White mulberry leaves are the preferred feedstock for silkworms, and are also cut for food for livestock (cattle, goats, etc.) in areas where dry seasons restrict the availability of ground vegetation. The fruit are also eaten, often dried or made into wine.^[2][3]

In traditional Chinese medicine, the fruit is used to treat prematurely grey hair, to "tonify" the blood, and treat constipation and diabetes.^{[citation needed]} The bark is used to treat cough, wheezing, edema, and to promote urination. It is also used to treat fever, headache, red dry and sore eyes, as well as cough.

For landscaping, a fruitless mulberry was developed from a clone for use in the production of silk in the U.S. The industry never materialized, but the mulberry variety is now used as an ornamental tree where shade is desired without the fruit. [1] A weeping cultivar of white mulberry Morus alba 'Pendula' is a popular ornamental plant.^[7]

In culture

Pennsylvania state champion Morus alba at Longwood Gardens

An etiological Babylonian story that was later incorporated into Greek and Roman mythology attributes the reddish purple color of the white mulberry (Morus alba) fruits to the tragic deaths of the lovers Pyramus and Thisbe.

The "White Mulberry Tree" is title of a crucial chapter in Willa Cather's 1913 novel, O Pioneers!, in which two forbidden lovers are killed, a reference to the story of Pyramus and Thisbe.

This article contains too much jargon and may need simplification or further explanation. Please discuss this issue on the talk page, and/or remove or explain jargon terms used in the article. Editing help is available. (November 2009)

References

1. ^ ^{a b} Flora of China: Morus alba
2. ^ ^{a b c d} Suttie, J. M. (undated). FAO Report: Morus alba L.
3. ^ ^{a b c} Bean, W. J. (1978). Trees and Shrubs Hardy in the British Isles. John Murray ISBN 0-7195-2256-0.
4. ^ Taylor, P. E., Card, G., House, J., Dickinson, M. H., & Flagan, R. C. (2006). High-speed pollen release in the white mulberry tree, Morus alba L. Sexual Plant Reproduction 19 (1): 19-24 pdf file
5. ^ Burgess, K.S., Morgan, M., Deverno, L., & Husband, B. C. (2005). Asymmetrical introgression between two Morus species (M. alba, M. rubra) that differ in abundance. Molec. Ecol. 14: 3471–3483.
6. ^ http://plants.usda.gov/java/profile?symbol=MOAL
7. ^ http://plants.usda.gov/java/profile?symbol=MOAL

External links

Wikispecies has information related to: Morus (Moraceae)

Wikimedia Commons has media related to: Morus alba

Wikimedia Commons has media related to: Morus

• U.S. Forest Service Invasive Species Weed of the Week
• USDA GRIN White Mulberry
• Diagnostic photos, Morton Arboretum acc. 380*82-1
• USDA NRCS Plants Profile, Morus alba