Magnolia grandiflora, commonly known as the southern magnolia or bull bay, is a tree of the family Magnoliaceae native to the southeastern United States, from Virginia south to central Florida, and west to East Texas and Oklahoma. Reaching 27.5 m (90 ft) in height, it is a large, striking evergreen tree with large, dark green leaves up to 20 cm (8 in) long and 12 cm (4.5 in) wide, and large, white, fragrant flowers up to 30 cm (12 in) in diameter. Although endemic to the lowland subtropical forests on the Gulf and south Atlantic coastal plain, magnolia grandiflora is widely cultivated in warmer areas around the world. The timber is hard and heavy, and has been used commercially to make furniture, pallets, and veneer.
Magnolia grandiflora is a medium to large evergreen tree which may grow 120 ft (36.5 m) tall. It typically has a single stem (or trunk) and a pyramidal shape. The leaves are simple and broadly ovate, 12–20 cm (5–8 in) long and 6–12 cm (2–5 in) broad, with smooth margins. They are dark green, stiff and leathery, and often scurfy underneath with yellow-brown pubescence. The large, showy, lemon citronella-scented flowers are white, up to 30 cm (12 in) across and fragrant, with six to 12 petals with a waxy texture, emerging from the tips of twigs on mature trees in late spring. Flowering is followed by the rose-coloured fruit, ovoid, 7.5–10 cm (3–4 in) long, and 3–5 cm (1.5–2 in) wide.
Exceptionally large trees have been reported in the far southern United States. The national champion is a specimen in Smith County, Mississippi, that stands an incredible 37 m (122 feet). Another record includes a 35-m-high specimen from the Chickasawhay District, De Soto National Forest, in Mississippi, which measured 17.75 ft in circumference at breast height, from 1961, and a 30-m-tall tree from Baton Rouge, which reached 18 ft in circumference at breast height.
Magnolia grandiflora was one of the many species first described by Linnaeus in his Systema Naturae in 1759, basing his description on the earlier notes of Miller. He did not select a type specimen. Its specific epithet is derived from the Latin words grandis "big", and flor- "flower".
M. grandiflora is most commonly known as southern magnolia, a name derived from its range in the Southern United States. Many broadleaved evergreen trees are known as bays for their resemblance to the leaves of the red bay (Persea borbonia), with this species known as the bull bay for its huge size or alternatively because cattle have been reported eating its leaves. Laurel magnolia, evergreen magnolia, large-flower magnolia or big laurel are alternative names. The timber is known simply as magnolia.
Distribution and habitat
Southern magnolias are native to the Southeastern United States, from southeast Virginia south to central Florida, and then west to East Texas and Oklahoma. It is found on the edges of bodies of water and swamps, in association with sweetgum (Liquidambar styraciflua), water oak (Quercus nigra), and black tupelo (Nyssa sylvatica). In more sheltered habitats, it grows as a large tree, but can be a low shrub when found on coastal dunes. It is killed by summer fires, and is missing from habitats that undergo regular burning.
In Florida, it is found in a number of different ecological areas that are typically shady and have well-draining soils; it is also found in hummocks, along ravines, on slopes, and in wooded floodplains. Despite preferring sites with increased moisture, it does not tolerate inundation. It grows on sand-hills in maritime forests, where it is found growing with live oaks and saw palmetto. In the eastern United States, it has become an escape, and has become naturalized in the tidewater area of Virginia and locally in other areas outside of its historically natural range.
Magnolia grandiflora can produce seed by 10 years of age, although peak seed production is achieved closer to 25 years of age. Around 50% of seeds can germinate, and they are spread by birds and mammals. Squirrels, opossums, quail, and turkey are known to eat the seeds.
Cultivation and uses
The plant collector Mark Catesby, the first in North America, brought M. grandiflora to Britain in 1726, where it entered cultivation and overshadowed M. virginiana, which had been collected a few years earlier. It had also come to France, the French having collected it in the vicinity of the Mississippi River in Louisiana. It was glowingly described by Philip Miller in his 1731 work The Gardeners' Dictionary. One of the earliest people to cultivate it in Europe was Sir John Colliton of Exeter in Devon; scaffolding and tubs surrounded his tree, where gardeners propagated its branches by layering, the daughter plants initially selling for five guineas each (but later falling to half a guinea).
It is often planted in university campuses and allowed to grow into a large tree, either with dependent branches, or with the lower branches removed to display the bare trunks. It is also espaliered against walls, which improves its frost-hardiness.