Willis Linn Jepson:

California Botanist, Ecologist & Biogeographer

Robert 'Roy' J. van de Hoek
May 26, 2001
Malibu, California

Willis Linn Jepson (1867-1946) was 25 years old in 1892, when together with John Muir and Warren Olney, at an attorney's office in San Francisco, formed the Sierra Club. During his lifetime, Jepson wrote at least 11 books, two of which were on Califoria's trees. He was a Professor of Botany at the University of California for four decades. Jepson traveled widely in California, on foot, by automobile, but he even took a steamship to Catalina Island in 1908 and a rowboat down the Colorado River in 1912, all in the search of plants and wild nature. Jepson published numerous articles, in Madrono, Erythea, and the Sierra Club Bulletin. He formed the California Botanical Society and the Save the Redwoods League.

Jepson coined the word alien plant in California in 1893. He was the first one to refer to a tree as a weed, Ailanthus altissima, but known to many people as the tree from hell. In Indonesia, where it is native, it is known as Aylanto. Whatever the name of this alien tree, it is one of the most toxic and poisonous plants found in California today. It is spreading through all the major cities of the United States, with an estimated population of over 1.7 million trees. I have noted it as particularly abundant in Omaha, Reno, and Los Angeles, but there are over 100 cities with this pernicious weed tree invading as an alien species.

I keep my Jepson books together on the same shelf; Trees of California is next to Flora of California, which is next to the Jepson Manual (1925), which is next to the new Jepson Manual (1993). I am partial to Jepson, if for no other reason than that he explored Catalina, allowing a woman named Blanche Trask to be his guide, then praised her profusely in his monumental Silva of California published shortly thereafter. He attended her funeral service in 1916 with Alice Eastwood also present. He wrote about the Blanche Trask Service in his field book for 1916. Jepson noted that two endemic Catalina Island plants were brought to the Service by Alice Eastwood.

1893: Alien Plants in California. Erythea 1:141-143.
1893. The Riparian Botany of the Lower Sacramento. Erythea 1:239-246.
1893. On A Variety of the Western Sumach. Erythea 1:140-141.
Willis Linn Jepson (1867-1946). By L.Constance, 1947, Science 105:614.
Rowboat Botanizing on the Colorado River, 1912. By R.Beidleman, 2001, Fremontia 28:3-12.
Catalina Botanical Journey, 1908. By R.van de Hoek, 1998, 12p.