|Morus alba |
The white mulberry is widely cultivated to feed the silkworms employed in the commercial production of silk. It is also notable for the rapid release of its pollen, which is launched at over half the speed of sound.
Botanical descriptionOn 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.
The white mulberry is scientifically notable for the rapid plant movement involved in pollen release from its catkins. The stamens act as catapults, releasing stored elastic energy in just 25 µs. The resulting movement is approximately 350 miles per hour (560 km/h), over half the speed of sound, making it the fastest known movement in the plant kingdom.
CultivationChina. In 2002, 6,260 km2 of land were devoted to the species in China.
The species is now extensively planted and widely naturalized throughout the warm temperate world. It has been grown widely from India west through Afghanistan and Iran to southern Europe for over a thousand years for leaves to feed silkworms.
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. As a result, it is listed as an invasive plant in parts of North America.
UsesWhite 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.
In traditional Chinese medicine, the fruit is used to treat prematurely grey hair, to "tonify" the blood, and treat constipation and diabetes. 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. A weeping cultivar of white mulberry, Morus alba 'Pendula', is a popular ornamental plant.
Medicinal UsesDental caries: The root bark of Morus alba (Moraceae) has been used as a traditional medicine in Asian countries and exhibits antibacterial activity against food poisoning micro-organisms. Using activity against S. mutans in bioassay-guided fractionation of a methanol extract of dried root bark, and organic solvent fractions of this extract, the active antibacterial constituent was identified as kuwanon G. The compound displayed an MIC of 8 μg ml–1 against S. mutans, which was comparable to chlorhexidine and vancomycin (1 μg ml–1). Time-kill assays indicated that S. mutans was completely inactivated by 20 μg ml–1 kuwanon G within 1 min, while testing against other bacteria suggested that the compound displayed preferential antimicrobial activity against cariogenic bacteria. Electron microscopic examination of S. mutans cells treated with kuwanon G indicated that the mode of antibacterial action was inhibition or blocking of cell growth, as treated cells showed a disintegrated surface and an unclear cell margin.
Hypolipidemic and antioxidant effects from freeze-dried powder of mulberry (Morus alba L.) fruit
Neuroprotective effects in in vitro and in vivo (fruit) 
Treatment of hyperuricemia and gout
Albanol A(1),isolated from the root bark extract of Morus alba may be a promising lead compound for developing an effective drug for treatment of leukemia.
Moracin M , Steppogenin-4′-O-β-D-glucosiade , Mullberroside A were isolated from the root bark of Morus alba L. and all produced hypoglycemic effects.
A methanol extract of Morus alba roots showed adaptogenic activity, indicating its possible clinical utility as an antistress agent.
Morus alba leaf extract help restore the vascular reactivity of diabetic rats. Free radical-induced vascular dysfunction plays a key role in the pathogenesis of vascular disease found in chronic diabetic patients. 
An ethanolic extract of mulberry leaf had antihyperglycemic, antioxidant and antiglycation effects in chronic diabetic rats, which may suggest its use as food supplement for diabetics.
Other usesAn acidified methanolic extract of the fruit of morus alba can be used as an acid-base indicator in acid-base titrations. Titration shows sharp colour change at the equivalence point. This is a natural indicator that is useful, economical, simple and accurate for determining acids and bases.
Snakebite "Morus alba plant leaf extract has been studied against the Indian Vipera/Daboia russelii venom induced local and systemic effects. The extract completely abolished the in vitro proteolytic and hyaluronolytic activities of the venom. Edema, hemorrhage and myonecrotic activities were also neutralized efficiently. In addition, the extract partially inhibited the pro-coagulant activity and completely abolished the degradation of A α chain of human fibrinogen. Thus, the extract processes potent antisnake venom property, especially against the local and systemic effects of Daboia russelii venom."
In cultureAn 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.
- Pennsylvania state champion Morus alba at Longwood Gardens.