Benghal dayflower, Commelina benghalensis
Commelina benghalensis, commonly called Benghal dayflower or tropical spiderwort, is an invasive noxious weed native to tropical Asia and Africa. In 1983, Benghal dayflower was classified as a federal noxious weed by the USDA. Benghal dayflower will compete with field and forage crops for resources. The weed is a menace to more than 20 crops, including cotton and soybeans. Once established in an agricultural area, it can seriously reduce crop yields. This invader is tolerant of glyphophosate and many other pre- and post-emergence herbicides. Herbicide efficacy decreases as seedling size increases. In October 2013, Benghal dayflower was first detected in South Carolina. Clemson-DPI is actively working to eradicate this noxious weed before it becomes established in our state and causes damage to native ecology and agriculture.
There are several common species of dayflower in South Carolina that look a lot like the regulated species. Benghal dayflower can be found spreading out of flower beds, but it is usually more erect than its native relatives. The invasive species has rounder, more egg-shaped leaves than other dayflowers and has characteristic red hairs on the leaf sheath. Further more, Benghal dayflower is the only Commelina species with below ground flowers. These subterranean, self-pollinated flowers produce two different types of seed in addition to the two types of seed the above ground flowers produce. All four types of seed have varying requirements for germination, making treatment more difficult. Not only does this weed reproduce via seed, but any plant material containing a node will reproduce vegetatively. If you suspect you have Benghal dayflower on your property, avoid disturbing the area as much as possible. If you must enter the area, be sure to clean all equipment, including your shoes, before leaving the infested area.
If you think you have found Benghal dayflower, please contact DPI at firstname.lastname@example.org or 864.646.2140.