Groundsel Tree, Beach Botany

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Groundsel Tree, Baccharis halimifolia, a wetland member of the Asteraceae family. A multibranched evergreen shrub up to 12’ in both height and width. Leaves are simple and alternate on the branches. Leaf shape ovate to obovate. Margins are widely serrated with coarse teeth. Leaf color greenish. Length 1 1/2” to 3” and 1” to 1/1/2” wide.  Leaves are leathery.

Halimifolia is dioecious. Male and female flowers are on different trees. These tiny flowers are borne in thousands of tiny flower heads. Flower structures are not similar to sunflower structures of disk and ray florets. The male flower is borne in flower heads. Its structure is spherical. About 1/8” in diameter. Several yellow stamens with pollen laden anthers cover the flower. Color is yellow. Female flowers are in erect flower heads about 1/8” long with several flowers per head. Color is snow white. Both male and female flowers bloom at the end of branches. The inflorescence is terminal. Fruit occurs with female flowers. Fruit is an achene seed pod that is attached to tuffs of cotton like bristle. Female flowers are wind pollinated and its seeds are dispersed by wind. The bristles pull out the seeds and goes with the wind.

Halimifolia is disbursed in every county of the State. This plant has a tendency to colonize. Often the male tree is right next to the female. This shrub grows in Matanzas Pass Preserve. Monarch butterflies on their flight to Mexico will rest on the trees and enjoy the nectar. The photo shows two female flowers covered in bristles. Each flower is about 1/18” wide.