MIKE, I knew you were good for one good post here!!!!!!!!
Duckweed is actually a non native plant
Landoltia punctata is a small, non-native, floating plant which can grow into dense masses in stagnant water bodies. Landoltia punctata usually has two leaves attached together. The leaves are shoe-shaped, which makes it resemble a large Lemna species. Landoltia punctata has 2-5 roots descending from each leaf.
This plant is easily confused with the native plant, giant duckweed, Spirodela polyrhiza. Landoltia duckweed is smaller than Spirodela polyrhiza, is more shoe-shaped, does not have a red dot on top, usually has only up to 4 roots, and sometimes has a red margin on the underneath of the leaves. The native giant duckweed is larger, has rounder leaves, some have a red dot on the top, has up to 9 and more roots, and is dark red underneath the leaves.
http://plants.ifas.ufl.edu/node/222
The plant is edible, blended in soups usually by foragers. The chinese use it to treat flatulence and acute kidney infections. It is hydroponic, the tiny root hairs siphon nutrients from the water. I have studied Florida edible plants for a while but still learning, and have never seen it in P1.
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