Proserpinaca pectinata Lam.
Habitat: Sandy bogs of the coastal plain [Open wetland, not coastal nor rivershore (non-forested, wetland)]
Range: Nova Scotia south to Florida, west to Texas.
Aids to Identification: Mermaid-weed is an emergent aquatic perennial plant, sometimes growing out of water and creeping along the substrate. Mermaid-weed appears very similar to some milfoils (genus Myriophyllum) in Maine, with highly dissected foliage and small axillary flowers. Mermaid-weed differs from these milfoils in having only alternate leaves, perfect flowers (as opposed to monecious in milfoils), and 4 separate carpels (3 united carpels in milfoils).
Ecological characteristics: Often found submerged in shallow water or in open wetlands.
Phenology: Flowering and fruiting July through September.
Synonyms: None noted.
Known Distribution in Maine: This rare plant has been documented from a total of 4 towns in the following counties: Cumberland , Hancock, Oxford.
Reason(s) for rarity: Approaching northern limit of range. Not rare southward.
Conservation considerations: Invasive aquatic plants could pose a threat to populations.