The nightshade family, Solanacae, includes many economically important plants, some very invasive exotic pest plants, and some plants that are pretty weedy. American black nightshade (Solanum americanum) is an agricultural weed and likely native to Florida, though there is some controversy about its origin. It grows throughout the southern U.S.
After Hurricane Jeanne broke open the canopy of live oaks (Quercus virginiana) at the Oslo Riverfront Conservation Area in 2004, one of the first plants to flourish in response to the disturbance and to the dramatically increased sunlight was American black nightshade. Unfortunately, I do not have photos from that time when this plant tried to fill in the trails. A few black American nightshades were seen growing in shaded hammock trails at Treasure Shores Park on our 6/3/2017 field trip and are the source of the photos in this post.
Black nightshade (the botanical name once was Solanum nigrum), common nightshade, garden nightshade, glossy nightshade, small flowered nightshade, and ink-berry (which is used for far too many different plants) are other common names for this plant. Black or nigrum refers to its very glossy black fruits, which, reportedly, are edible when completely ripe (but there does seem to be some controversy about this matter, as well).
Green fruits and the leaves of this annual plant are toxic, though the leaves can be boiled and re-boiled in clean water multiple times like the leaves of American pokeweed (Phytolacca americana), to remove the toxins. The alternate leaves are ovate (egg-shaped) or lanceolate (lance-shaped) with scalloped or delicately toothed leaves margins (edges) and are held on a rough, erect central stem.
Flowering in Florida occurs throughout the entire year. The white bell-shaped flowers have 5 fused petals and 5 yellow anthers that form a cone around the pistil (the female part of the flower that contains the ovary). Bees are its primary pollinator.
Flowering and fruiting often occurs at the same time. Each berry contains from 50 – 100 seeds. 90% of the seeds germinate and can survive in the soil for more than 6 years.
The fruits are eaten and spread by a variety of birds as diverse as the Northern Cardinal, Gray Catbird, Robin, Eastern Meadowlark, Eastern Bluebird, Wood Duck, and Wild Turkey. If you are intentionally growing this easy-to-propagate annual in your yard or cultivating a volunteer plant (likely a bird-gift), American black nightshade is bird-feed. If it compromising the yield of your cultivated crop, it is a weed. Beauty (and weediness) is in the eye of the beholder.