Plants of Isle Royale National Park

Flora of a Lake Superior Archipelago

Isle Royale National Park (Michigan) hosts a boreal forest flora shaped by Lake Superior's moderating climate, glacial history, and isolation.

Conifers (Dominant Canopy)

• Balsam Fir (Abies balsamea) – Most abundant; shade-tolerant.
• Eastern White Pine (Pinus strobus) – Tall emergent; historic logging target.
• Jack Pine (Pinus banksiana) – Fire-adapted; serotinous cones.
• Red Pine (Pinus resinosa) – Sandy soils; long-lived.
• White Spruce (Picea glauca) – Cool, moist sites.
• Black Spruce (Picea mariana) – Bogs, wetlands.
• Northern White Cedar (Thuja occidentalis) – Calcareous shores.
• Tamarack (Larix laricina) – Deciduous conifer; wetlands.

Hardwoods

• Sugar Maple (Acer saccharum) – Rich soils; fall color.
• Red Maple (Acer rubrum) – Wide tolerance.
• American Beech (Fagus grandifolia) – Mesic forests.
• Yellow Birch (Betula alleghaniensis) – Cool, moist.
• Paper Birch (Betula papyrifera) – Pioneer, fire-follower.
• Quaking Aspen (Populus tremuloides) – Clonal; post-fire.
• Balsam Poplar (Populus balsamifera) – Floodplains.

Shrubs

• Mountain Maple (Acer spicatum), Speckled Alder (Alnus incana), Common Juniper (Juniperus communis), Dwarf Blueberry (Vaccinium cespitosum), Highbush Cranberry (Viburnum trilobum), Beaked Hazelnut (Corylus cornuta), Bush Honeysuckle (Diervilla lonicera).

Wildflowers (Spring–Summer)

• Canada Anemone, Large-flowered Trillium, Bluebead Lily, Wood Lily, Yellow Trout Lily, Starflower, Bunchberry, Lady's Slipper (Cypripedium), Wild Sarsaparilla.

Ferns & Allies

• Bracken, Lady Fern, Maidenhair Fern, Oak Fern, Interrupted Fern, Clubmosses (Lycopodium), Horsetails.

Bryophytes & Lichens

• Sphagnum moss (bogs), Feather Moss, Haircap Moss, Reindeer Lichen (Cladonia), Beard Lichen (Usnea), Lungwort (Lobaria).

Notable Absences

No native oak, hickory, pine marten, porcupine, black bear (extirpated), wolf (recolonizing via ice bridge).

The park's flora reflects its boreal character and island biogeography.