Nature Bulletin No. 753   April 25, 1964
Forest Preserve District of Cook County
Seymour Simon, President
Roberts Mann, Conservation Editor

****:THE LOMBARDY POPLAR

Some of us who soldiered in France during World War I remember 
highways and canals lined on both sides, for miles, with tall trees so 
straight and narrow that they resembled Grecian columns -- columns 
such as those which now surround the Lincoln Memorial in 
Washington. They were called "Lombardy Poplars". Younger men 
who soldiered in northern Italy during World War II may recall seeing 
such trees along the Po and other rivers where some of them are as 
much as six feet in diameter and 150 feet tall.

The Lombardy, like all its ilk -- black poplars, white poplars, balsam 
poplars, cottonwoods and aspens -- grows rapidly. In America our 
native cottonwoods frequently became huge and very tall, but the 
Lombardy does not live long enough to attain such size. In the 
midwest we rarely see one that is more than 10 inches in diameter and 
50 feet tall. In eastern states they may become somewhat larger.

With age, because of the nearly vertical growth of its many branches 
and the numerous sprouts that spring up around its base, a Lombardy 
becomes a most striking and picturesque tree. Ever since it originated, 
accidentally, on the plains of Lombardy during the early 1700's, it has 
been extensively planted in Europe and England as a landscape 
feature.

There was a time when this poplar was widely used for that purpose 
here in Chicagoland. We recall long rows of them lining the entrance 
drives on country estates, and clumps of them in rolling meadows or 
on the crests of ridges. Many suburban home owners had a few along 
the rear of their lots. Even today, some people try to grow them in 
ignorance or in defiance of the fact that virtually all earlier plantings 
gradually died and have disappeared.

In America the Lombardy commonly becomes infected with a canker 
disease that eats into the trunk and eventually kills the tree. It is also a 
favorite target for destructive attacks by the "poplar borer", a native 
beetle distributed generally over the northern United States, Canada, 
and southward to Texas.

The adult beetles, from 1 to 1-1/2 inches in length, are a light gray 
with yellowish spots and the whole body is sprinkled with tiny black 
dots. In autumn a female deposits her eggs in cracks on a poplar's 
bark. After a few days they hatch into small grubs which feed at first 
on the outer bark and then chew their way into the sapwood. They 
start feeding again as soon as the weather becomes warm in spring and 
continue until late autumn, cutting out galleries as much as an inch in 
diameter. At least 2 years are required for them to become about 2 
inches long, pupate, and emerge as adult beetles in July or September.

On infested trees, many of those burrows are noticeable on the bark of 
the trunk and larger branches. The entrances are usually packed with 
excelsior-like wood fibers and discharge sap which discolors the bark. 
On the ground there may be accumulations of sawdust. Eventually the 
tree dies or is so weakened that its trunk breaks off during a high 
wind.

All true species of poplars, cottonwoods and aspens are diocecious: the 
staminate (male) and pistillate (female) flowers are borne on separate 
trees. The Lombardy poplar, however, is not a true species. Apparently 
it originated as a "sport" -- a mutation of the black poplar in Italy -- 
one of those quirks of nature that have occurred from time to time. It 
exists only as a male tree, produces no seed, and must be propagated 
by cuttings.

The Lombardy is so common in and characteristic of the older 
Mormon settlements in Utah and other western states that out there. it 
is commonly known as "the Mormon tree".