Thursday, July 24, 2008

Black walnut

What do walnuts, Wales, Walloon, Welsh, Walsh, Wallace, and Cornwall have in common? The words all indicate foreignness.

Walnuts are foreign nuts, and the "wal-" in their name indicates that fact. Foreign to whom? To the English. The American Heritage Dictionary explains the history nicely: "Although Celtic-speaking peoples were living in Britain before the arrival of the invaders...whose languages would eventually develop into English, it was the Celts and not the invaders who came to be called 'strangers' in English. Our words for one of the descendants of the Celtish peoples, Welsh, and for their homeland, Wales, come from the Old English word wealh, meaning 'stranger'.... Old English...walhhnutu [exists] in a document from around 1050.... This eventually became walnut in English...literally the 'foreign nut.' The nut was 'foreign' because it was native to Roman Gaul and Italy."(1)

Black walnut (Juglans nigra) is an American native closely related to the Persian walnut (Juglans regia) of Europe and Asia. It grows wild in the eastern United States except for parts of New York and New England.(2) The tree is highly valued for its wood and for its nuts. The wood is so valuable that black walnuts are at risk of being felled and stolen by "walnut rustlers." For that reason, I won't specify the locations of the pictured Plainfield trees. Walnuts have been prized since ancient times. The Romans esteemed them highly enough to call them Jupiter's nut (Jovis glans) from which the scientific name Juglans derives.(3)

Walnuts have pinnately compound leaves (with leaflets arranged like a feather), each leaf a foot or two in length and made up of as many as 23 leaflets. The leaflets are serrated, and the leaflet at the tip of the leaf is often undersized or missing, a useful feature in identification. The leaves emit a spicy odor when crushed. They turn yellow in the autumn and are among the earliest leaves to fall.

The bark is dark gray-brown and deeply furrowed, forming diamond shapes.

The nuts fall around the same time as the leaves and are covered by a fleshy green hull that will stain your hands black if you try to remove it. Breeders have produced over 500 varieties of black walnut, trying to create nuts with a thinner shell and a less convoluted inner structure so that the kernel is easier to extract.

Almost as well-known as its delicious nuts and its beautiful wood is walnut's toxic effect on neighboring plants. This effect has been known for millennia. Pliny the Elder wrote in the first century AD that, "the shadow of walnut trees is poison to all plants within its compass." Juglone, the toxin that the tree produces to keep the rest of the natural world at bay, is present in leaves, branches, bark, roots, and nuts. The chemical is toxic to a variety of other plants. Don't, for example, plant tomatoes near a walnut tree. The toxin's victims are not limited to plants. Bruised walnut leaves and branches have been put into water by fishermen to stun fishes.

(1) The American Heritage Dictionary of the English Language, Houghton Mifflin Company 2000. See the entry for Wales.

(2) Edward Goodell, Walnuts for the Northeast, Arnoldia 44: 1-19, 1984.

(3) The Romans' walnut was Juglans regia, Persian walnut. It is also called English walnut. But, as discussed above, there really is no such thing as an English walnut.

Copyright Gregory Palermo

Thursday, July 3, 2008

Sweetbay magnolia

I have fragrant roses in my garden, but I can never detect their scent unless I put my nose right down into a bloom. The difficulty isn't an insensitive sense of smell. It is, rather, that I have a sweetbay magnolia in bloom at the same time. The fragrance of the magnolia is so potent that it overwhelms the scent of the roses.

Sweetbay magnolia (Magnolia virginiana) blooms over about six weeks from May into early July. Its flowers are small and never make a big visual impact. They bloom a few at a time, each flower lasting only a few days. Their fragrance is huge. To my nose their scent is rose-like, but much more intense.

There is a very handsome sweetbay magnolia in front of 500 Stelle Avenue.

The flowers are followed by shiny, bright red, clustered fruits(1) that ripen in August and September. The fruit is a favorite food of catbirds and mockingbirds. The photograph below shows unripe fruits on July 1.

Sweetbay magnolias are closely enough related to southern magnolias to have been hybridized with them. Unlike southern magnolias, sweetbays are mostly deciduous in this climate. Sweetbay flowers are much smaller and much more fragrant than southern magnolia flowers. Sweetbay leaves are duller and have a silvery gray underside that displays itself very attractively in a breeze.

Another feature that helps with identification is the rather smooth, light gray bark.

Sweetbays grow into large trees in the southern United States. In New Jersey a height of 25 to 30 feet is typical.

I have grown one of the hybrids of sweetbay and southern magnolias, 'Timeless Beauty'. The flowers of the hybrid resembled southern magnolia flowers. The foliage was less attractive than that of either southern or sweetbay magnolia. Worse, the hybrid's foliage suffered winter burn in winters that left pure southern magnolias unscathed. All in all, a disappointing plant.

Sweetbay magnolias are underutilized. Any garden can benefit from having their fragrance for six weeks in late spring and early summer. Very adaptable plants, they are tolerant of both wet soil and shade. A peculiarity of sweetbay magnolias is that they make a dense network of roots just beneath the soil surface. Mulch your beds heavily and the roots will grow right into the mulch. When the mulch dwindles with time, you are left with "aerial" roots. A drawback to this beautiful New Jersey native is that deer eat the leaves and stems.

Sweetbays were the first magnolias imported into Europe from the Americas. The genus was named by Linnaeus after Pierre Magnol, pioneering botanist and physician to the court of Louis XIV.

(1) The fruits are aggregates of follicles.
Copyright Gregory Palermo