Aquatic plants live in, under, or on water and include a wide variety of species from different plant families with varying habits. Those that live fully submerged may float in the water, as in hornwort (Ceratophyllum), or be rooted to the bottom, as in eelgrass (Vallisneria). In some cases, rooted aquatics have leaves that float on the surface, as in water lilies (Nymphaea), while free-floating plants can also live primarily on the surface, as with duckweed (Lemna). On the bank, plants that live with their roots and the lower parts of their stems submerged are known as marginals, and cattail (Typha) is a good example. Last but not least, bog plants in general live fully above the water, but the soil they are rooted in is wet to moist, with moisture guaranteed year-round. Skunk cabbage (Lysichiton) can tolerate some submersion, especially in winter, but generally grows as a bog plant.

Photos 1 - 4: Drosera rotundifolia, Lysichiton americanus, Nymphaea lotus, Sarracenia purpurea.

Bogs offer several challenges to the plants that live in them. The wet soil is often anaerobic, with little oxygen for the roots. Bog soils are also poor in essential nutrients, plus water levels fluctuate over the seasons, drying out in summer and flooding in winter. To tackle the low-oxygen soils, many bog and aquatic plants develop aerenchyma or air channels, allowing gas exchange between the roots below the water and the leaves above. Insufficient nutrient availability can be tackled via carnivory, with dead insects supplementing the diet. Bog plants such as sundews (Drosera), pitcherplants (Sarracenia), and false asphodels (Triantha) extract nitrogen from their prey. An evergreen habit, as in bog-laurel (Kalmia microphylla) and heather (Calluna vulgaris), and underground storage structure (bulbs, rhizomes) also reduce nutrient wastage.

Skunk cabbage is a member of the Arum family (Araceae) native from Alaska south to California. American (or yellow) skunk cabbage (Lysichiton americanus) is not closely related to the skunk cabbage (Symplocarpus foetidus) of eastern North America, but rather to a species from eastern Asia (Lysichiton camtschatcensis). Like all arums, its flowers are tiny and clustered together on a thick spike called a spadix, surrounded by a leathery bract called a spathe. The spadix releases a pungent fragrance that attracts pollinating flies and beetles. Mature seeds drop into the bog to germinate or are carried elsewhere by flowing water. Skunk cabbage grows from a rhizome resting deep in the soil, within which it can store nutrients that are otherwise difficult to access in the boggy soil.