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.)

The most widely distributed species of Magnolia in the flora, M. virginiana occurs in two growth forms: deciduous and often multitrunked northward, and typically single-trunked and evergreen in the southern range. Where these forms overlap geographically in North Carolina and adjacent areas, intergradation occurs, and the identification of these intergrades is difficult, if not impossible. It has been impossible to pinpoint their occurrence in the zone of overlap. Herbarium specimens cannot be trusted to resolve this dilemma. Both filiform and flagelliform trichomes occur on the leaves, but these are without taxonomic significance. Some investigators have treated these habital variants as geographic varieties or as subspecies, but infraspecific taxa are not recognized here. Without other defining characteristics and no clear geographic correlation, infraspecific taxa have little significance or taxonomic value in M. virginiana. A thorough field study is needed to clarify the taxonomy of this otherwise well-known plant.

Magnolia virginiana is widely cultivated. It was the first magnolia known in Europe, dating from 1688 in England. A few cultivars of both the deciduous and evergreen forms are now grown in cultivation. Magnolia virginiana is a parent of several hybrids, including the first known magnolia hybrid, M.× thompsoniana (Loudon) C. de Vos (=M. virginiana × M. tripetala), dating to 1808. Other hybrids include the so-called Freeman hybrids of M. grandiflora × M. virginiana and M. virginiana × M. hypoleuca with its cultivar 'Nimbus'.

The largest known tree of Magnolia virginiana (the evergreen form), 28m in height with a trunk diameter of 1.4m, is recorded from Union County, Arkansas (American Forestry Association 1994).

The Houma and Rappahannock tribes used decoctions of leaves, twigs, and bark of Magnolia virginiana to treat colds and chills, to warm the blood, and as a hallucinogen (D.E. Moerman 1986).

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