Magnolia grandiflora (a hexaploid) is highly variable, especially the leaves, which range from glabrous to densely red-brown felted on the abaxial surface. It is the only magnolia species in the flora with free stipules, and the inner spathaceous bract is unique among Magnolia taxa in the flora. Curled filiform trichomes occur on the abaxial leaf surface. In the wild, hybrids with M. virginiana (a diploid) have been reported but not confirmed by the present author. The compatibility of these taxa is well known from the Freeman hybrid, a highly sterile tetraploid growing at the U.S. National Arboretum in Washington, D.C. In crosses using the hexaploid M. grandiflora , this parent is dominant and nearly masks the other parent.
Magnolia grandiflora is an escape, and it naturalizes in the tidewater area of Virginia and locally elsewhere beyond its natural range in the southeastern United States. It ranks among the noblest of North American broadleaved trees and is cultivated widely in the United States and in many other countries. A large number of cultivars have been introduced to horticulture.
Southern magnolia ( Magnolia grandiflora ) is the state tree of both Louisiana and Mississippi.
The largest known tree of Magnolia grandiflora, 37.2m in height with a trunk diameter of 1.97m, is recorded from Smith County, Mississippi (American Forestry Association 1994).
The Choctaw and Koasati tribes used the bark of Magnolia grandiflora as dermatological and kidney aids (D.A. Moerman 1986).
Handsome tree to 30 m; winter terminal bud 1-2.5 cm, evidently hairy; lvs scattered or somewhat clustered toward the ends of the twigs, leathery, evergreen, elliptic, 12-25 cm, a third or half as wide, acute to obtuse, basally acute to rounded-obtuse, the lower surface conspicuously rusty with a ±persistent, thin, villous tomentum; fls fragrant, creamy-white, cup-shaped, ca 10 cm thick; pet 6-12, obovate or spatulate, broadly rounded distally, concave, 7-13 cm; fr cone ellipsoid, 6-10 cm, the follicles woolly- villous; 2n=ca 114. Rich woods and moist bottomlands; coastal plain from se. Va. to Fla. and Tex. Apr.-June.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.