Free Republic

Japanese knotweed evolved in one of the harshest environments on Earth – now scientists are desperately trying to find a way to destroy it. Where it does produce seeds, Japanese knotweed is prolific. At one research site in Philadelphia, the plants were found to produce up to 150,000 seeds each year per stem – most of which were found to be viable. This two-part system, with above-ground and below-ground body parts, means it's extremely difficult to control Japanese knotweed with chemicals. The most effective is glyphosate, which works by inhibiting an enzyme plants need to produce amino acids, and the...

Writing in the Journal of Ethnobiology, Natalie Muellert, assistant professor of archaeology in Arts & Sciences, describes how she painstakingly grew and calculated yield estimates for two annual plants that were cultivated in eastern North America for thousands of years—and then abandoned. Growing goosefoot (Chenopodium, sp.) and erect knotweed (Polygonum erectum) together is more productive than growing either one alone, Mueller discovered. Planted in tandem, along with the other known lost crops, they could have fed thousands. Archaeologists found the first evidence of the lost crops in rock shelters in Kentucky and Arkansas in the 1930s. Seed caches and dried...