Flora of North America species comparison

Considerable variation in depth of lobing occurs in the leaves of Quercus alba (M. J. Baranski 1975; J. W. Hardin 1975); the species is easily distinguished from others, however, by the light gray-green, glabrous mature leaves and cuneate leaf bases.

In the past Quercus alba was considered to be the source of the finest and most durable oak lumber in America for furniture and shipbuilding. Now it has been replaced almost entirely in commerce by various species of eastern red oak (e.g., Q. rubra, Q. velutina, and Q. falcata) that are more common and have faster growth and greater yields. These red oaks also lack tyloses and therefore are more suited to pressure treating with preservatives, even though they are less decay-resistant without treatment.

Medicinally, Quercus alba was used by Native Americans to treat diarrhea, indigestion, chronic dysentery, mouth sores, chapped skin, asthma, milky urine, rheumatism, coughs, sore throat, consumption, bleeding piles, and muscle aches, as an antiseptic, and emetic, and a wash for chills and fevers, to bring up phlegm, as a witchcraft medicine, and as a psychological aid (D. E. Moerman 1986).

Numerous hybrids between Quercus alba and other species of white oak have been reported, and some have been named. J. W. Hardin (1975) reviewed the hybrids of Quercus alba. Nothospecies names based on putative hybrids involving Q. alba include: Q. ×beadlei Trelease (= Q. alba × prinus), Q. ×bebbiana Schneider (= Q. alba × macrocarpa), Q. ×bimundorum E. J. Palmer (= Q. alba × robur), Q. ×deami Trelease (= Q. alba × muhlenbergii), Q. ×faxoni Trelease (= Q. alba × prinoides), Q. ×jackiana Schneider (= Q. alba × bicolor), and Q. ×saulei Schneider (= Q. alba × montana).

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

The name Quercus prinus Linnaeus is often applied to this species, particularly in the forestry literature, and in many regional floras. In a number of works, however, Q. prinus has been applied to the species here treated as Q. michauxii. Following the recommendations of J. W. Hardin (1979), because of the persistent confusion in the application of the name Q. prinus and uncertainty regarding the identity of the Linnean type materials, the names Q. montana and Q. michauxii should be used for the two species that have been variously called Q. prinus. Quercus prinus under this interpretation is a name of uncertain position.

The four species of the chestnut oak group in eastern North America (Quercus montana, Q. michauxii, Q. muhlenbergii, and Q. prinoides) are somewhat difficult to distinguish unless careful attention is paid to features of leaf vestiture and fruit and cup morphology. Attempts to identify these species mostly or solely on basis of leaf shape and dentition (as in many other oak species complexes) have resulted in a plethora of misidentified material in herbaria and erroneous reports in the literature. The closely appressed, asymmetric trichomes on the abaxial surface of the mature leaf, in combination with longer simple hairs along the midvein, are unique to Q. montana among North American species of Quercus. Immature leaves and densely shaded leaves sometimes exhibit a more erect trichome that could be confused with the longer, felty hairs of Q. michauxii, so it is important to evaluate mature sun leaves when possible.

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