Species of the Week
Number 10 -- August 7, 2006

In the Species of the Week feature of the Wildwood Web we took a close look at one of the species that lives in Wildwood.  To see the earlier featured species check the Species of the Week archives.

Nodding Onion Allium cernuum There are a lot of onions in the world.  The genus Allium, the wild and cultivated onions, has between 550 and 700 species worldwide, mostly in the northern hemisphere.  There are 96 in North America, which, while a quite respectable number, is trivial compared to the number in the Old World.  Many familiar kitchen staples are in this genus, onions of all colors, chives, shallots, leeks, scallions, and garlic.  The genus name, Allium, in fact, is Latin for "garlic."  A number of other species are grown for the ornamental flowers. Onions used to be in the Liliaceae, the Lily Family.  This family, however, has long been recognized as containing too many plants not clearly related to each other.  No one could come up with a way to divide the family up, however, that was satisfactory to all botanists.  Recently the techniques of molecular biology have been used to study the evolutionary relationships of the members of this family.  By studying the similarities and differences of the genes in the DNA of the various plants, scientists were able to show how the plants were related.  The result, which is gaining increasing acceptance among botanists, is that the family has been divided into about a dozen smaller families.  The onions are now in the Onion Family, the Alliaceae.

Nodding onion is unusual among the onions in that most of the flowers nod or hang downwards on the flower stalk, as is easily seen in the picture above. The species name, in fact, means "nodding."  The flowers, which are bell shaped with six lobes, are white, pink or rose.   The leaves are typical onion leaves, like the leaves of scallions.  Like all onions, it grows from an underground bulb.  Bulb and leaves smell of onion.

Nodding onion grows on rocky banks, in dry woods and on prairies.  It has an interesting distribution.  It likes mountains and cool places, and is found in the three separate areas.  In the west it follows the Rockies from British Columbia and Alberta south to Arizona and New Mexico and into Mexico.  In the East it follows the Appalachians from New York south to Tennessee and North Carolina, and extends west to Indiana, northern Illinois and southeastern Wisconsin.  In between it can also be found in the Ozarks of Arkansas and Missouri.

In Wildwood it favors open areas, especially the rocky banks under the power lines along Wildwood Drive where it is currently putting on quite a show.  Look for its beautiful nodding blossoms as you hike along the road.

GGC