Flora of North America species comparison

The disposition of Magnolia macrophylla and its close relative M. ashei has been perplexing since M. ashei was described. Some investigators have treated them as geographic varieties or subspecies, and this has some questionable merit. In the foliar state M. macrophylla is hardly, if at all, distinguishable from M. ashei, but in other morphologic details of flower and fruit, they are readily distinguished. They also differ in the floral odors, which are distinct and chemically different (L.B. Thien et al. 197). Magnolia macrophylla and M. ashei are allopatric. Magnolia macrophylla is a much larger, usually single-trunked tree of the piedmont with a wider distribution, larger leaves, more stamens, larger stipules, and both filiform and flagelliform trichomes on the leaves. The follicetum is nearly globose-ovoid, with more pistils and larger seeds. Magnolia macrophylla produces the largest leaves and flowers of any species of the genus.

In Arkansas Magnolia macrophylla was known from a single disjunct locality in Clay County, where only two trees were recorded in 1981 (R.B. Figlar 1981). A survey in 1995 failed to locate the species in the same site.

This handsome tree is occasionally cultivated. A close relative, M. dealbata Zuccarini, occurs in Mexico.

The largest known tree of Magnolia macrophylla, 32m in height with a trunk diameter of 53 cm, is recorded from Daniel Boone National Forest, Tight Hollow, Kentucky (American Forestry Association 1994).

The Cherokee tribe used Magnolia macrophylla, mainly the bark, as an analgesic, antidiarrheal, gastrointestinal aid, respiratory aid, and toothache remedy (D.E. Moerman 1986).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

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).

(Discussion copyrighted by Flora of North America; reprinted with permission.)