Leavenworth’s Tickseed, Coreopsis leavenworthii, a member of the Asteraceae family, is found in almost every county in Florida. Pine Flatwoods, marshes, disturbed sites, and swales are home to this species.
A single erect main stem grows from a tap root with fibrous roots to height between 11/2 and 3 feet. The main stem is rounded and extremely narrow, around 1/8” in diameter. Leaves are opposite and widely spaced on the stem. Leaf shape is also about 1/8” wide and up to five or six inches in length.
Secondary stems grow parallel to the main stem from the leaf axils. Flower head stalks also occur in the leaf axils. Flower structure is the typical Aster Sunflower with yellow ray florets surrounding a black disc made up of perhaps 100 tiny tubular disc florets. There are eight ray florets each with three fused petals. Flower diameter is around 1”. As many as two dozen flowers may be in bloom at the same time. Seeds are distributed by the wind.
There are 13 species of Coreopsis in Florida with two being non-native. Tickseed is also the State native flower. I have seen Tickseed growing at Bowditch Point Park. It also sometimes appears alongside Estero Blvd. I found the specimen in the picture five years ago in a field somewhere in Hendry County.