Of interest this week at Beal...

Moth mullein Verbascum blattaria Family: the Figwort family, Scrophulariaceae Also called Spurious mullein and Slippery mullein W. J. Beal Botanical Garden The moth mullein, Verbascum blattaria, is a common weed of fields and lawns across Eurasia, where it is native, as well as most of temperate North America where it was introduced along the East Coast. It is recorded from Pennsylvania in 1818 and Michi- gan in 1840.

This species is comprised of populations with yellow, pinkish white, or mixed flower colors. In central Michigan, the yellow examples seem to predominate. Moth mullein is a biennial, forming a rosette in its first year or growth. It is upholstered with prominent glandular hairs (photo below, far left) that adorn its 3 to 5 ft (1 to 1.5 meter) flowering stalk in its second year.

An abstract rendition of the Moth mullein flower is the iconic image at the core of the W. J. Beal Botanical Garden logo (above left). Its presence there pays homage to the founder, William James Beal, as well as to one of his most famous science experiments.

In order to explore how long buried plant seeds could survive, Beal started what has become known as the “Beal Seed Viability Experiment” in the fall of 1879. This effort is still ongoing, and comprises the longest continuously running science experiment known anywhere.

Beal buried 20 bottles of seeds, with each bottle containing 21 species of mostly weed species. (For details, see http://www.cpa.msu.edu/beal/research/research_frames.htm) During the first 40 years, a bottle was scheduled to be unearthed every 5 years. In 1920, Beal’s successor in the experiment, Dr. H. T. Darlington, increased the inter- val for recovering successive bottles to 10 years. In the 100th year of the experiment (1980) Dr. R. S. Bandursky lengthened the interval again to 20 years.

After 120 years, Moth mullein is the only species that has been successfully germinated during every trial, although there was a single germination of a common mallow, Malva The centers of Moth mullein flowers,Verbascum blattaria, dis- play many fine purple and white hairs, although the word ‘hairs’ doesn’t seem to do justice to the spun-glass appearance they ex- hibit under magnification. Some have suggested they resemble moth antennae; a possible origin for the common name.

neglecta, that germinated after a cold treatment of the seeds from the latest (2000) bottle recovered. (See Telewski and Zeevaart 2000, Vol 89, American Journal of Botany.)

Even in folk medicine, Moth mullein did not acquire a wide selection of uses, in contrast to its relative Velvet mullein, Verbascum thapsus. However, Supavarn et. al, in 1974, reported that a methanol extract of Moth mullein killed at least 53 percent of the exposed Aedes aegypti mosquito larvae when tested at a concentration of 1000 parts per million.