Brief SummaryRead full entry
Southern magnolia (Magnolia grandiflora) is the state tree of both Louisiana and Mississippi. This evergreen tree is native to the coastal plains of the southeastern United States (Virginia and central Florida west to eastern Texas), where it occurs in abundance. It occurs in rich loamy soils of wooded dunes, hammocks, and along rivers of the bottom and low upland plains between 60-150 m (180-450 feet) in altitude. It cannot withstand inundation from flooding, and it is also susceptible to frost. A beautiful and useful tree, it is also commonly planted in parks and streets in mild climates around the world, and over 50 cultivars are commercially available. It was collected and brought to Great Britain in 1726 whence began a long history of cultivation in Europe and Asia. Southern magnolia is also known as bull bay (partly because cattle reportedly eat its leaves), big-laurel, evergreen magnolia, and large-flower magnolia.
The largest known Magnolia grandiflora tree, from Smith County, Mississippi, measured 37.2m (112 feet) in height. It is a moderately fast growing species, more usually reaching a height of 15 m (50 feet) tall. Southern magnolia trees have large, dark green, leathery, oval leaves, about 12-20 cm (5-8 inches) long, which it does not shed in winter. The undersides of the leaves have a bronze-red brown fuzzy surface, and the twigs are also red and fuzzy. Young trees develop a large taproot.
In late spring, the trees produce large, cup-shaped flowers, 30 cm (12 inches) across. The flowers give off a sweet lemony scent. Growing from thick stems all over the tree, the flowers have delicate waxy, white petals that bruise easily. These showy blossoms are open for three days, when they are pollinated by bees, and close up each night. Flowers give way to cone-shaped fruits that, when mature, bear the trees prolific crop of bright red seeds. The seeds have a fleshy coat over an inner stone, and attach to the fruit with silky white threads. They dangle from these threads until eaten by birds and mammals, including squirrels, opossums, quail and turkey, which disperse the seeds. Seeds do not germinate under parent trees, as adult trees produce chemicals to inhibit potentially competing seedlings.
In its habitat, southern magnolia seldom grows alone. It is shade tolerant, especially when young. It is commonly found alongside hardwood trees including American beech, sweetgum, yellow-poplar, live oak, southern red oak, white oak, and hickories. The cork bark of older magnolia trees allows the trees to survive fire, although seedlings are quickly killed. Where fires are suppressed, southern magnolia become dominant (climax) species in mixed hardwood forests, often along with live oak.
People have used Southern magnolia for many uses. These include:
- Its hard and heavy timber is used commercially to make furniture, pallets, and veneer.
- Because the tree is resistant to acid deposition from pollutants such as sulfur dioxide it is good for urban landscaping.
- Magnolia grandiflora produces phenolic antimicrobial chemicals, compounds called coumarins and sesquiterpene lactones, which discourage predation and grazing. Choctaw and Koasati tribes used the bark of Magnolia grandiflora as dermatological and kidney aids. In northern Pakistan, oil is extracted from leaves and flowers and pounded leaves are used for toothache. Extracts from its leaves, fruits, bark and wood have potential applications as pharmaceuticals.
- Its dense, evergreen foliage harbors wildlife, providing coverage for many small birds and mammals, even in urban settings.
(Clark et al. 1981; E.-Feraly and Chan 1978; Halls 1977; Outcalt 1990; Wikipedia 2016; Yang et al. 1994)