Morus alba, known as white mulberry, common mulberry and silkworm mulberry, is a fast-growing, small to medium-sized mulberry tree which grows to 10–20 m (33–66 ft) tall. It is generally a short-lived tree with a lifespan comparable to that of humans, although there are some specimens known to be more than 250 years old. The species is native to central China and is widely cultivated and naturalized elsewhere (including United States, Mexico, Australia, Kyrgyzstan, Argentina, Turkey, Iran, India, and many others).
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 greater than half the speed of sound. Its berries are edible when ripe.
Description
On young, vigorous shoots, the leaves may be up to 30 cm (12 in) long, and deeply and intricately lobed, with the lobes rounded. On older trees, the leaves are generally 5–15 cm (2.0–5.9 in) long, unlobed, cordate at the base and rounded to acuminate at the tip, and serrated on the margins. Generally, the trees are deciduous in temperate regions, but trees grown in tropical regions may be evergreen.
The flowers are single-sex catkins; male catkins are 2–3.5 cm (0.8–1.4 in) long, and female catkins 1–2 cm (0.4–0.8 in) long. Male and female flowers are usually found on separate trees although they may occur on the same tree. The fruit is 1–1.5 cm (0.4–0.6 in) 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 in the droppings of birds that eat the fruit.
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 380 miles per hour (610 km/h), about half the speed of sound, making it the fastest known movement in the plant kingdom.
Cultivation
Mulberry leaves placed on trays with silkworms (Liang Kai’s Sericulture c. 1200s)
Cultivation of white mulberry to nourish silkworms began more than 4,700 years ago in China and has since been introduced in other countries. The Ancient Greeks and Romans cultivated the mulberry for silkworms. At least as early as 220 AD, Emperor Elagabalus wore a silk robe. It was introduced into other parts of Europe in the twelfth century and into Latin America after the Spanish conquest in the fifteenth century. In 2002, 6,260 km2 of land were devoted to the species in China.
It has been grown widely from the Indian subcontinent west through Afghanistan and Iran to southern Europe for more than a thousand years for leaves to feed silkworms.
More recently, it has become widely naturalized in disturbed areas such as roadsides and the edges of tree lots, along with urban areas in much of North America, where it hybridizes readily with the locally native red mulberry (Morus rubra). There is now serious concern for the long-term genetic viability of the red mulberry because of extensive hybridization in some areas.
The species is now extensively planted and widely naturalized throughout the warm temperate world and in subarctic regions as well, and would survive in elevations as high as 4,000 metres (13,000 ft). They thrive in mildly acidic, well drained, sandy loam and clayey loam soils. Though they can withstand poor soils as well.
Uses
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 leaves are prepared as tea in Korea. The fruit are also eaten, often dried or made into wine.
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 cultivar of white mulberry, Morus alba ‘Pendula’, is a popular ornamental plant. It was planted at several grand stations built along the Lackawanna Railroad in New Jersey during the late 1800s and early 1900s. The species has become a popular lawn tree across the desert cities of the southwestern United States, prized for its shade and also for its cylindrical berry clusters composed of sweet, purplish-white fruits. The plant’s pollen has become problematical in some cities where it has been blamed for an increase in hay fever.
White mulberry, which is known scientifically as Morus alba, is a type of tree native to certain parts of China and India.
The tree is notable for its long leaves, petalless flowers, and small berries, which range in color from white to pink or dark purple.
Today, white mulberry is grown worldwide, and the leaves are commonly used to feed silkworms and other livestock.
The fruit also has a sweet, somewhat tart flavor and is often used to make juice, tea, jam, or dried snacks.
The leaves, bark, root, and fruit of the white mulberry tree are likewise used in traditional medicine and have recently been studied for their potential health-promoting properties.
Supplements containing white mulberry extract are widely available and can be found in capsule or liquid form at many natural health stores.
White mulberry fruit is rich in several important nutrients, including fiber, vitamin C, and iron.
One ounce (28 grams) of raw white mulberries contains the following:
- Calories: 90
- Protein: 3 grams
- Fat: 0.5 grams
- Carbs: 22 grams
- Fiber: 4 grams
- Vitamin C: 130% of the Daily Value (DV)
- Iron: 20% of the DV
- Calcium: 8% of the DV
- Vitamin A: 2% of the DV
White mulberries are especially rich in vitamin C, a water-soluble vitamin that acts as an antioxidant to neutralize harmful free radicals and alleviate inflammation.
They’re also high in iron, a key mineral involved in DNA synthesis and oxygen transport.
White mulberries may be associated with several health benefits.
Extracts may slow cancer cell growth
White mulberries are rich in various cancer-fighting antioxidants, including flavonoids, alkaloids, and phenolic acids.
According to one animal study, specific compounds isolated from white mulberries reduced the growth of breast cancer cells in mice.
Similarly, another test-tube study showed that white mulberry root bark extract blocked the division and spread of colorectal cancer cells, as well as induced cancer cell death.
What’s more, other test-tube studies have found that white mulberry extract may be effective against colon and cervical cancers.
However, keep in mind that these studies focused on the effects of a concentrated amount of mulberry extract directly on cancer cells in test tubes, as well as isolated compounds derived from mulberry.
Therefore, more research is needed to determine how mulberry may affect cancer cell growth in humans when used as a supplement or consumed in typically consumed amounts.
Reduces cholesterol levels
Some research suggests that white mulberry could help decrease cholesterol levels and improve heart health.
In one animal study, white mulberry leaf tea reduced triglycerides, total cholesterol, and LDL (bad) cholesterol in mice.
Another animal study showed that administering mulberry extract to rats on a high cholesterol diet decreased both total and LDL cholesterol.
Still, additional studies are needed to evaluate how white mulberry may affect cholesterol levels in humans.
May improve blood sugar control
Several studies have found that white mulberry and its components may help improve blood sugar management.
One small study in 24 people with type 2 diabetes found that consuming 1,000 mg of mulberry leaf extract 3 times daily for 3 months significantly reduced blood sugar levels after meals, compared with a control group.
It also improved levels of hemoglobin A1C, which is a marker used to measure long-term blood sugar regulation, although this was not statistically significant.
In another study in 12 healthy adults, a compound isolated from mulberry leaf extract was shown to improve blood sugar regulation after 12 weeks.
One animal study also found that administering mulberry leaves to mice helped maintain the function of beta cells in the pancreas, which are responsible for insulin production
White mulberry extract supplements are widely available at many natural health stores and typically found in capsule, liquid, or tea form.
Most supplement manufacturers recommend consuming white mulberry tea or capsules with meals to promote better blood sugar management.
Meanwhile, the liquid extracts are usually mixed into a beverage of your choice and consumed a few times per day to support overall health.
Although there’s no official recommended dosage for white mulberry, most supplement manufacturers advise taking 1,000–3,000 mg per day for best results.
For most people, white mulberry can be enjoyed as part of a healthy, well-rounded diet with little risk of adverse side effects.
Although allergic reactions to white mulberry are very uncommon, they have been reported.
Mulberry fruit has also been shown to trigger an allergic reaction in people who are sensitive to birch pollen due to cross-reactivity.
That said, be sure to talk with your healthcare professional before using white mulberry extracts, teas, or supplements, especially if you have any underlying health conditions or are taking medications.
