Pictured Rocks National Lakeshore abounds with rich and healthy plant communities, including upland forests, swampy lowlands, bogs and fens, vegetated dunes, successional fields, inland lakes, and riparian groves. Over 600 plant species have been identified.
The park's proximity to the moderating effect of Lake Superior results in many micro-habitats that shield plants normally ranging further south and north. Rare arctic disjuncts such as dwarf raspberry and arctic crowberry, which normally live far to the north in Canada, find a home in cooler, sheltered pockets of Upper Peninsula forests like those at Pictured Rocks.
The lakeshore's upland forests are dominated by sugar and red maple, beech, yellow birch, and hemlock. Wetland soils that have developed since the most recent glacial recession give rise to spruce, tamarack, alder, and white cedar communities. Streams and lakes are ringed with balsam and striped maple. The Grand Sable Dunes contain a rare collection of habitats with jack pine pockets, willow, the federally threatened Pitcher’s thistle, Lake Huron tansy and several state threatened species of fern.
Larger submerged aquatic plants and those that are emergent from the water surface provide habitat for algae, protozoa, invertebrates, and fish. There are 76 plants generally categorized as aquatic in the park’s waters. The smallest plants of Pictured Rocks National Lakeshore include hundreds of taxa of algae including dinoflagellates, green algae, yellow-brown algae, and diatoms.