While working on a jobsite today in the Slaughterhouse Branch forested steam valley in Baltimore, Leslie and I observed a plant species in bloom that neither of us have seen before.
I knew the plant was a loosestrife (Lysimachia), but which one of the 16 species native to Maryland, I did not know. Out came the diagnostic taxonomy books and phone apps.
The plant turns out to be Fringed Loosestrife (Lysimachia ciiata), and called “fringed” due to the conspicuous hairs on its petioles (leaf stalks), but not on the main stem. I’ve added an arrow to show the hairs, which only the fringed (hairy) loosestrife has, and is therefore the primary diagnostic.
The yellow flowers have five petals, and droop from the stalks, which arise from the axils of the opposite leaves. The sepals on the back of the flowers are usually streaked, which does not show well in this picture.
The star-shaped flowers taper to slender pointed tips.
The plant (FACW) is typically found along the borders of streams, as was our case, and is a perennial native throughout the USA.
The plant usually flowers in July in Maryland. We observed 10 plants in a loose aggregate of a 30-foot radius, along the active floodplain of the rocky, perennial stream.