Kudzu (Pueraria montana) - NONNATIVE INVASINE in the U.S.
by Leo Shapiro, EOL
Although native to Asia, Kudzu (Pueraria montana var. lobata) is among the most widespread and abundant invasive weeds in the eastern United States. Although its stronghold in North America is in the southeastern United States, its range extends into the northeastern and northcentral United States as well.
The deciduous vines arise from massive perennial starchy root crowns, which can reach down to 4 m deep in the soil and weigh up to 136 kg. These massive roots provide energy for rapid initial growth in spring. Kudzu dies back to the ground after a hard freeze, but maximal growth rate in spring has been reported to be around 0.3 m per day and a plant may grow 20 to 30 m in a growing season. The fragrant purple flowers typically appear only on vines that are growing vertically on some support. Flowers occur on pseudoracemes, unusual inflorescences in which multiple flowers emerge from each bract axil.
Before Kudzu’s invasive potential was recognized, it was repeatedly introduced into the southeastern United States for use as an ornamental and forage crop and for erosion control (Mitich 2000). Its subsequent rapid spread occurred despite conspicuously low seed set. Plants rarely flower before their third year and in some North American populations flowering is rarely if ever observed. In other areas, vines produce many flowers, but these often yield low numbers of seed pods or seed pods containing few seeds. In North America, many Kudzu populations sustain heavy losses to seed predators…
(read more: EOL)
(images: T - Jan Carroll; BL - Gerritt Davidse, MIssouri Botanical Garden; BC - Barry Rice; BR - Steve Hurst, USDA - NRCS Plants Database)