As a professional a garden coach, designer and maintainer, I am frequently asked to identify plants that have ‘just appeared’ on a property. When unsure of an identity I grab a couple of photos and head for two websites, The Connecticut Botanical Society and Go Botany. I have yet to come away without a positive ID.
The most recent ‘mystery’ plant needing identification turned out to be Jimsonweed – aka thorn-apple – botanical name Datura stramonium, a herbaceous perennial considered invasive in Connecticut. I’ve seen this Datura, aka Jimsonweed, in two separate cultivated perennial gardens this year where it had never been spotted before.
With photos downloaded to the computer, it’s easy to compare the mystery plant to website photos. The Connecticut Botanical Society has a handy ‘by flower color’ search option in the Wildflower section. For this identification I looked through the pink and blue/purple selections. Among the pink flower colors I noted the native wildflower, Swamp Rose-mallow (Hibiscus moscheutos or H. palustris) with somewhat similar flower structure but with very different leaves. There were no like flowers in the blue/purple section.
Further inquiry took me to Go Botany, a relatively new plant ID search feature of the New England Wild Flower Society. To ID plants click on Get Started in the Simple ID Key section, where your next choice is to look under Woody plants, Aquatic plants , Grass-like plants, Orchids and related plants, Ferns, or All other flowering non-woody plants. I followed All other flowering non-woody plants then Other herbaceous flowering plants with alternate leaves.
Once individual plant photos upload simply scroll through the photos to find your plant, or narrow the selections down by answering questions about the New England state in which the plant was seen and then scroll through photos or further narrow the choices by answering questions regarding leaf type, flower petal color, leaf arrangement, and so forth.
Click on the name of your mystery plant for more information, then click on Go To Species Page for more in depth facts. My search took me here: https://gobotany.newenglandwild.org/species/datura/stramonium/?pile=alternate-remaining-non-monocots. Datura is native to tropical America but has colonized north to New England states. It is an annual, has night-opening flowers pollinated by Sphinx moths, and is poisonous. Fruit capsules have thorn-like defensive structures and split open to disperse ripened seeds.
Had each property owner not taken the time to ask for a positive identification the two Jimsonweeds could have flowered and set seed, further adding to the plant’s invasiveness. In our age of global commerce, plants are transported all over the world. Some become invasive in regions that have no natural predators or controls. Climate change is also contributing to regional shifts in plant growth.
Not all mystery plants end up being invasive. I recently used similar steps to identify the ‘just appeared’ woolsedge (Scirpus cyperinus) growing along the woodland edge of my yard. Because woolsedge is native to Connecticut I will let it set seed and, hopefully, will see more of it growing next year.
The seed of both the woolsedge and the jimsonweed may have come in via bird droppings or with the winds of Superstorm Sandy. I’ve often noticed mystery plants, insects and diseases show up the growing season following strong wind storms. Have you?