This is the pistillate flower of Black Ash, Fraxinus nigra, (Keeler, 1915).

Black Ash Flower

This is the pistillate flower of Black Ash, Fraxinus nigra, (Keeler, 1915).

This is the fruit, or samara, of Black Ash, Fraxinus nigra, (Keeler, 1915).

Black Ash Fruit

This is the fruit, or samara, of Black Ash, Fraxinus nigra, (Keeler, 1915).

This is the fruit, or drupe, of Fringe-tree, Chionanthus virginica, (Keeler, 1915).

Fringe-tree Fruit

This is the fruit, or drupe, of Fringe-tree, Chionanthus virginica, (Keeler, 1915).

This is the fruit of the Sassafras,(Keeler, 1915).

Sassafras Fruit

This is the fruit of the Sassafras,(Keeler, 1915).

This is the flowering spray of White Elm, Ulmus americana, (Keeler, 1915).

White Elm Flowers

This is the flowering spray of White Elm, Ulmus americana, (Keeler, 1915).

These are the unfolding leaves of White Elm, Ulmus americana, (Keeler, 1915).

White Elm Leaves

These are the unfolding leaves of White Elm, Ulmus americana, (Keeler, 1915).

These are the fruit, or samara, of White Elm, Ulmus americana, (Keeler, 1915).

White Elm Fruit

These are the fruit, or samara, of White Elm, Ulmus americana, (Keeler, 1915).

These are the fruit, or samara, of Slippery Elm, Ulmus pubescens, (Keeler, 1915).

Slippery Elm Fruit

These are the fruit, or samara, of Slippery Elm, Ulmus pubescens, (Keeler, 1915).

These are the fruit, or samara, of Cork Elm, Ulmus racemosa, (Keeler, 1915).

Cork Elm Fruit

These are the fruit, or samara, of Cork Elm, Ulmus racemosa, (Keeler, 1915).

These are the fruit, or samara, of Winged Elm, Ulmus alata, (Keeler, 1915).

Winged Elm Fruit

These are the fruit, or samara, of Winged Elm, Ulmus alata, (Keeler, 1915).

These are the fruit of Red Mulberry, Morus rubra, (Keeler, 1915).

Red Mulberry Fruit

These are the fruit of Red Mulberry, Morus rubra, (Keeler, 1915).

These are the fruit of Sycamore, Platanus occidentalis, (Keeler, 1915).

Sycamore Fruit

These are the fruit of Sycamore, Platanus occidentalis, (Keeler, 1915).

These are the staminate flowers of Shellbark Hickory, Hicoria ovata, (Keeler, 1915).

Shellbark Hickory Flower

These are the staminate flowers of Shellbark Hickory, Hicoria ovata, (Keeler, 1915).

This is the fruit of Bitternut, Hicoria minima, (Keeler, 1915).

Bitternut Fruit

This is the fruit of Bitternut, Hicoria minima, (Keeler, 1915).

This is the fruit of Mockernut, Hicoria alba, (Keeler, 1915).

Mockernut Fruit

This is the fruit of Mockernut, Hicoria alba, (Keeler, 1915).

This is the branch of Red Birch, Betula nigra, showing the staminate aments as they appear in winter, (Keeler, 1915).

Red Birch

This is the branch of Red Birch, Betula nigra, showing the staminate aments as they appear in winter,…

This shows the four staminate and one pistillate ament of Sweet Birch, Betula lenta, (Keeler, 1915).

Sweet Birch Branch

This shows the four staminate and one pistillate ament of Sweet Birch, Betula lenta, (Keeler, 1915).

This shows the pendulous strobiles, or fruit, of the White Birch, Betula populifolia, (Keeler, 1915).

White Birch Fruit

This shows the pendulous strobiles, or fruit, of the White Birch, Betula populifolia, (Keeler, 1915).

This shows the pendulous strobiles, or fruit, of the Paper Birch, Betula papyrifera, (Keeler, 1915).

Paper Birch Fruit

This shows the pendulous strobiles, or fruit, of the Paper Birch, Betula papyrifera, (Keeler, 1915).

This shows the erect strobile, or fruit, of the Red Birch, Betula nigra, (Keeler, 1915).

Red Birch Fruit

This shows the erect strobile, or fruit, of the Red Birch, Betula nigra, (Keeler, 1915).

This shows the erect strobile, or fruit, of the Yellow Birch, Betula lutea (Keeler, 1915).

Yellow Birch Fruit

This shows the erect strobile, or fruit, of the Yellow Birch, Betula lutea (Keeler, 1915).

This shows the erect strobile, or fruit, of the Sweet Birch, Betula lenta (Keeler, 1915).

Sweet Birch Fruit

This shows the erect strobile, or fruit, of the Sweet Birch, Betula lenta (Keeler, 1915).

This shows the branch of Hop Hornbeam, Ostrya virginiana, showing the staminate aments as they appear in winter,(Keeler, 1915).

Hop Hornbeam Branch

This shows the branch of Hop Hornbeam, Ostrya virginiana, showing the staminate aments as they appear…

This shows the pistillate and staminate aments of Hop Hornbeam, Ostrya virginiana, (Keeler, 1915).

Hop Hornbeam Flowers

This shows the pistillate and staminate aments of Hop Hornbeam, Ostrya virginiana, (Keeler, 1915).

This shows the pistillate and staminate aments of Hornbeam, Carpinus caroliniana, (Keeler, 1915).

Hornbeam Flowers

This shows the pistillate and staminate aments of Hornbeam, Carpinus caroliniana, (Keeler, 1915).

This shows a sprouting acorn (Keeler, 1915).

Acorn

This shows a sprouting acorn (Keeler, 1915).

This shows the staminate flower of Scarlet Oak, Quercus coccinea, (Keeler, 1915).

Scarlet Oak Flowers

This shows the staminate flower of Scarlet Oak, Quercus coccinea, (Keeler, 1915).

This shows the pistillate flower of Scarlet Oak, Quercus coccinea, (Keeler, 1915).

Scarlet Oak Flowers

This shows the pistillate flower of Scarlet Oak, Quercus coccinea, (Keeler, 1915).

This shows the acorn of Post Oak, Quercus minor, (Keeler, 1915).

Post Oak Acorn

This shows the acorn of Post Oak, Quercus minor, (Keeler, 1915).

This shows the acorn of Bur Oak, Quercus macrocarpa, (Keeler, 1915).

Bur Oak Acorn

This shows the acorn of Bur Oak, Quercus macrocarpa, (Keeler, 1915).

This shows the acorn of chestnut Oak, Quercus prinus, (Keeler, 1915).

Chestnut Oak Acorn

This shows the acorn of chestnut Oak, Quercus prinus, (Keeler, 1915).

This shows the acorn of Yellow Oak, Quercus acuminata, (Keeler, 1915).

Yellow Oak Acorn

This shows the acorn of Yellow Oak, Quercus acuminata, (Keeler, 1915).

This shows the acorn of Chinquapin Oak, Quercus prinoides, (Keeler, 1915).

Chinquapin Oak Acorn

This shows the acorn of Chinquapin Oak, Quercus prinoides, (Keeler, 1915).

This shows the acorn of Swamp White Oak, Quercus platanoides, (Keeler, 1915).

Swamp Oak Acorn

This shows the acorn of Swamp White Oak, Quercus platanoides, (Keeler, 1915).

This shows the acorn of Red Oak, Quercus rubra, (Keeler, 1915).

Red Oak Acorn

This shows the acorn of Red Oak, Quercus rubra, (Keeler, 1915).

This shows the acorn of Scarlet Oak, Quercus coccinea, (Keeler, 1915).

Scarlet Oak Acorn

This shows the acorn of Scarlet Oak, Quercus coccinea, (Keeler, 1915).

This shows two leaves of Spanish Oak, Quercus digitata, (Keeler, 1915).

Spanish Oak Leaves

This shows two leaves of Spanish Oak, Quercus digitata, (Keeler, 1915).

This shows acorns of Spanish Oak, Quercus digitata, (Keeler, 1915).

Spanish Oak Acorn

This shows acorns of Spanish Oak, Quercus digitata, (Keeler, 1915).

This shows the acorn of Pin Oak, Quercus palustris, (Keeler, 1915).

Pin Oak Acorn

This shows the acorn of Pin Oak, Quercus palustris, (Keeler, 1915).

This shows the acorn of Bear Oak, Quercus ilicifolia, (Keeler, 1915).

Bear Oak Acorn

This shows the acorn of Bear Oak, Quercus ilicifolia, (Keeler, 1915).

This shows the acorn of Black Jack Oak, Quercus marilandica, (Keeler, 1915).

Black Jack Oak Acorn

This shows the acorn of Black Jack Oak, Quercus marilandica, (Keeler, 1915).

This shows the acorn of Shingle Oak, Quercus imbricaria, (Keeler, 1915).

Shingle Oak Acorn

This shows the acorn of Shingle Oak, Quercus imbricaria, (Keeler, 1915).

This shows the acorn of Willow Oak, Quercus phellos, (Keeler, 1915).

Willow Oak Acorn

This shows the acorn of Willow Oak, Quercus phellos, (Keeler, 1915).

This shows the unfolding leaves of the Beech branch, (Keeler, 1915).

Beech Branch

This shows the unfolding leaves of the Beech branch, (Keeler, 1915).

This shows the staminate flower of the Beech, (Keeler, 1915).

Beech Flower

This shows the staminate flower of the Beech, (Keeler, 1915).

This shows the pistillate flower of the Beech, (Keeler, 1915).

Beech Flower

This shows the pistillate flower of the Beech, (Keeler, 1915).

This shows the staminate and pistillate flower cluster of the Beech, (Keeler, 1915).

Beech Flower

This shows the staminate and pistillate flower cluster of the Beech, (Keeler, 1915).

This shows the staminate flower of the Willow, (Keeler, 1915).

Willow Flower

This shows the staminate flower of the Willow, (Keeler, 1915).

This shows the pistillate flower of the Willow, (Keeler, 1915).

Willow Flower

This shows the pistillate flower of the Willow, (Keeler, 1915).

This shows the staminate flower of the Black Willow, Salix nigra, (Keeler, 1915).

Black Willow Flower

This shows the staminate flower of the Black Willow, Salix nigra, (Keeler, 1915).

This shows the pistillate flower of the Black Willow, Salix nigra, (Keeler, 1915).

Black Willow Flower

This shows the pistillate flower of the Black Willow, Salix nigra, (Keeler, 1915).

This shows the leaf of the Almondleaf Willow, Salix amygdaloides, (Keeler, 1915).

Almondleaf Willow Leaf

This shows the leaf of the Almondleaf Willow, Salix amygdaloides, (Keeler, 1915).

This shows the leaf of the Longleaf Willow, Salix fluviatilis, (Keeler, 1915).

Longleaf Willow Leaf

This shows the leaf of the Longleaf Willow, Salix fluviatilis, (Keeler, 1915).

This shows the staminate aments of the cottonwood, Populus deltoides (Keeler, 1915).

Cottonwood Flowers

This shows the staminate aments of the cottonwood, Populus deltoides (Keeler, 1915).

This shows the pistillate aments of the cottonwood, Populus deltoides (Keeler, 1915).

Cottonwood Flowers

This shows the pistillate aments of the cottonwood, Populus deltoides (Keeler, 1915).

This shows the fruiting ament of Large-toothed Aspen, Populus grandidentata, (Keeler, 1915).

Large-Toothed Aspen Flowers

This shows the fruiting ament of Large-toothed Aspen, Populus grandidentata, (Keeler, 1915).

This shows the leaf of the Swamp Cottonwood, Populus heterophylla, (Keeler, 1915).

Swamp Cottonwood Leaf

This shows the leaf of the Swamp Cottonwood, Populus heterophylla, (Keeler, 1915).

This shows part of the fruiting ament of the Swamp Cottonwood, Populus heterophylla, (Keeler, 1915).

Swamp Cottonwood Fruit

This shows part of the fruiting ament of the Swamp Cottonwood, Populus heterophylla, (Keeler, 1915).

This shows the staminate flower of the Balsam, Populus balsamifera, (Keeler, 1915).

Balsam Flower

This shows the staminate flower of the Balsam, Populus balsamifera, (Keeler, 1915).

This shows the pistillate flower of the Balsam, Populus balsamifera, (Keeler, 1915).

Balsam Flower

This shows the pistillate flower of the Balsam, Populus balsamifera, (Keeler, 1915).