Leaf structure helps determine the differences between the Jamaican porterweed (S. jamai-censis) plant, left, and the Blue porterweed (S. cayennensis) plant, right. UF/IFAS PHOTO

Did you know? Stachytarpheta jamaicensis, or Jamaican porterweed, is the only porterweed native to Florida, a good point to keep in mind when searching for the plant to add to your landscape.

While this may be hard to believe, there are times when garden centers mislabel plants, either intentionally or unintentionally. So, how can you ensure you are getting S. jamaicensis, and not its non-native, Category II invasive counterpart, S. cayennensis? Especially since both are commonly sold as Blue porterweed.

You can begin by putting on your investigator cap. After checking the label, observe the plant’s leaf structure. If you note a rather smooth surface, with leaf margin “teeth” pointed toward the tip, you are viewing the native plant. The leaves of the non-native porterweed have a raised, quilted surface and more finely toothed margins than those of the native.

Although perhaps not as easily recognizable when observed in their growing containers, another tell can be the sprawling appearance of the native plant versus the upright growing habit of the non-native.

The native S. Jamaicensis enjoys full sun to partial shade and does well in a range of soil types. Growing to a height of 2 feet, the plant spreads horizontally 2-3 feet and is drought tolerant once established. Lovely, delicate lavender-blue flowers, each opening up for a day, grace 12-inch spikes.

Jamaican porterweed is host plant to the Tropical Buckeye butterfly, and is a nectar source for a variety of butterflies, including among others, Gulf fritillary (Agraulis vanillae), Julia (Dryas iulia) and clouded skipper (Lerema accius). In addition to butterflies, you may notice a variety of other pollinators, such as bees, in the vicinity enjoying the flavorful nectar. Propagation can be by seed or cuttings.

Not only can our wild friends benefit from having our native porterweed in the garden, but we can too! If you like the taste of mushrooms, you may wish to sample the plant’s flowers, which can be eaten raw. Take care though if you know that pesticides are being used in the area. You wouldn’t want to take in unwanted chemicals along with the tasty treat, that’s for sure! Another part of the plant that can serve our culinary tastes are the spikes. These can be used as you would bay leaves, to spice up a variety of dishes from soups to stews. And, as an extra bonus, dried leaves can be used in the making of tea.

The non-native S. cayennensis, also known as nettle-leaf porterweed, is an upright-growing woody shrub growing to 5 feet and spreading rapidly. Of most concern regarding the plant is its invasive nature. As a Category II invasive, S. cayennensis has become more abundant but has yet to change native plant communities to the extent that Category I invasive species have. However, it has been known to hybridze with our native porterweed when existing in close proximity, not a good sign when looking to maintain the distinctive nature of the native species.

Now that you have an understanding of what to look for, you will be better ensured of selecting just the right porterweed for your landscape, our beautiful native S. jamaicensis! Until next time…

Happy Gardening!

Janetta Fox is a Lee County Master Gardener and member of the Garden Club of Cape Coral. Visit us at gardenclubofcapecoral.com.