Redbud Tree in Bottom Land, Red River Gorge, Kentucky, April 17, 1968

Lava Tongues, Craters of the Moon [National Monument], Idaho, July 2, 1975

Lupin and Grass, Craters of the Moon [National Monument], Idaho, July 3, 1975

Mossy Boulder and Rhododendron, Red River Gorge, Kentucky, April 17, 1968

Polypody Ferns in Sandstone, Gray's Arch Trail, Red River Gorge, Kentucky, April 18, 1968

Dogwood and Oak Forest, Daniel Boone National Forest, Red River Gorge, Kentucky, April 18, 1968

Rock Bridge, Swift Camp Creek, Red River Gorge, Kentucky, April 19, 1968

Sandstone Cliff, Detail, Double Arch Trail, Red River Gorge, Kentucky, April 18, 1968

Cobweb and Moss, Maine, August 1942

Trailing Arbutus, Swift Camp Creek, Red River Gorge, Kentucky, April 19, 1968

Stern of Boat and Flowers, Great Spruce Head Island, Maine, August 8, 1954

Stern of Boat and Flowers, Great Spruce Head Island, Maine, August 8, 1954

Fungus on Log, Great Spruce Head Island, Maine, July 25, 1949

Hot Spring, Mývatn, Iceland, July 23, 1972

Violets on Moss-covered Boulder, Red River Gorge, Kentucky, April 17, 1968

Violets on Moss-covered Boulder, Red River Gorge, Kentucky, April 17, 1968

Pine Cones and Lava, Craters of the Moon [National Monument], Idaho, July 2, 1975

Dwarf Eriogonum and Lava, Craters of the Moon [National Monument], Idaho, July 3, 1975

Waterfall, Lake Hagavatn, Iceland, August 11, 1972

Dew on Spider Web, Great Spruce Head Island, Maine, July 31, 1954