Of the Composite family (Compositae), the rough hawkweed (Hieracium scabrum).

Rough Hawkweed

Of the Composite family (Compositae), the rough hawkweed (Hieracium scabrum).

Of the Composite family (Compositae), the Allegheny hawkweed (Hieracium paniculatum).

Allegheny Hawkweed

Of the Composite family (Compositae), the Allegheny hawkweed (Hieracium paniculatum).

Of the Composite family (Compositae), the lion's-foot (Prenanthes serpentaria).

Lion's-Foot

Of the Composite family (Compositae), the lion's-foot (Prenanthes serpentaria).

Of the Composite family (Compositae), the common dandelion (Taraxicum officinale).

Common Dandelion

Of the Composite family (Compositae), the common dandelion (Taraxicum officinale).

Of the Composite family (Compositae), the sow thistle (Sonchus oleraceus).

Sow Thistle

Of the Composite family (Compositae), the sow thistle (Sonchus oleraceus).

Of the arrowhead family (Sagittaria), the narrow-leaved arrowhead (Sagittaria subulata).

Narrow-Leaved Arrowhead

Of the arrowhead family (Sagittaria), the narrow-leaved arrowhead (Sagittaria subulata).

Of the arrowhead family (Sagittaria), Sagittaria heterophylla.

Sagittaria heterophylla

Of the arrowhead family (Sagittaria), Sagittaria heterophylla.

Of the arrowhead family (Sagittaria), the delta arrowhead (Sagittaria platyphylla).

Delta Arrowhead

Of the arrowhead family (Sagittaria), the delta arrowhead (Sagittaria platyphylla).

Of the arrowhead family (Sagittaria), the grassy arrowhead (Sagittaria graminea).

Grassy Arrowhead

Of the arrowhead family (Sagittaria), the grassy arrowhead (Sagittaria graminea).

Of the arrowhead family (Sagittaria), the slender arrowhead (Sagittaria teres).

Slender Arrowhead

Of the arrowhead family (Sagittaria), the slender arrowhead (Sagittaria teres).

Of the spiderwort family (Tradescantia), clockwise from top: T. bracteata, T. pilosa, T. montana, T. brevicaulis, T. occidentalis, T. reflexa.

Spiderwort

Of the spiderwort family (Tradescantia), clockwise from top: T. bracteata, T. pilosa, T. montana, T.…

Of the bead lily family (Clintonia), the white clintonia (Clintonia umbellulata).

White Clintonia

Of the bead lily family (Clintonia), the white clintonia (Clintonia umbellulata).

Featherbells or Stenanthium gramineum.

Featherbells

Featherbells or Stenanthium gramineum.

The Siberian geranium or Geranium sibiricum.

Siberian Geranium

The Siberian geranium or Geranium sibiricum.

The small geranium or Geranium pusillum.

Small Geranium

The small geranium or Geranium pusillum.

The awnless geranium or Geranium molle.

Awnless Geranium

The awnless geranium or Geranium molle.

Of the pink family (Caryophyllaceae), the larger mouse-ear chickweed (Cerastium vulgatum).

Larger Mouse-Ear Chickweed

Of the pink family (Caryophyllaceae), the larger mouse-ear chickweed (Cerastium vulgatum).

Of the pink family (Caryophyllaceae), the night-flowering catchfly (Silene noctiflora).

Night-Flowering Catchfly

Of the pink family (Caryophyllaceae), the night-flowering catchfly (Silene noctiflora).

Of the pink family (Caryophyllaceae), the wild pink (Silene Pennsylvanica).

Wild Pink

Of the pink family (Caryophyllaceae), the wild pink (Silene Pennsylvanica).

The grasslike starwort or Stellaria graminea.

Grasslike Starwort

The grasslike starwort or Stellaria graminea.

Of the pink family (Caryophyllaceae), the sleepy catchfly (Silene Antirrhina).

Sleepy Catchfly

Of the pink family (Caryophyllaceae), the sleepy catchfly (Silene Antirrhina).

Of the false mermaid family (Limnanthaceae), the false mermaid (Floerkea prosperpinacoides).

False Mermaid

Of the false mermaid family (Limnanthaceae), the false mermaid (Floerkea prosperpinacoides).

Of the mint family (Labiatae), the hedge nettle (Stachys palustris).

Hedge Nettle

Of the mint family (Labiatae), the hedge nettle (Stachys palustris).

Of the mint family (Labiatae), the false dragon-head (Physostegia Virginiana).

False Dragon-Head

Of the mint family (Labiatae), the false dragon-head (Physostegia Virginiana).

Of the mint family (Labiatae), the horehound (Marrubium vulgare).

Horehound

Of the mint family (Labiatae), the horehound (Marrubium vulgare).

Of the figwort family (Scrophulariaceae), the small snapdragon (Antirrhinum Orontium).

Small Snapdragon

Of the figwort family (Scrophulariaceae), the small snapdragon (Antirrhinum Orontium).

Of the figwort family (Scrophulariaceae), the figwort (Scrophularia marilandica).

Figwort

Of the figwort family (Scrophulariaceae), the figwort (Scrophularia marilandica).

"Rootstock of Cotton-Grass (Eriophorum)." -Bergen, 1896

Cottongrass

"Rootstock of Cotton-Grass (Eriophorum)." -Bergen, 1896

"Fruit-bud of pear, showing its development. A, opening in spring; B, later, developing flowers and leaves; C, later still; only one flower has produced a fruit, the rest having fallen off. Below it is a lateral bud which will continue the spur next year." -Bergen, 1896

Pear Fruit-Bud

"Fruit-bud of pear, showing its development. A, opening in spring; B, later, developing flowers and…

"Leaves standing nearly vertical in compass-plant. (Silphium laciniatum). A, view from east or west; B, from north or south." -Bergen, 1896

Compass Plant

"Leaves standing nearly vertical in compass-plant. (Silphium laciniatum). A, view from east or west;…

The Venus Flytrap.

Venus Flytrap

The Venus Flytrap.

"Flowers of willow. A, staminate flower; B, pistillate flower." -Bergen, 1896

Willow Flowers

"Flowers of willow. A, staminate flower; B, pistillate flower." -Bergen, 1896

"Transition from bracts to sepals in a cactus flower." -Bergen, 1896

Bracts to Sepals

"Transition from bracts to sepals in a cactus flower." -Bergen, 1896

"Bees visiting flowers. At the left, a bumblebee on the flower of the dead nettle; below, a similar bee in the flower of the horse-chestnut; above, a honey-bee in the flower of a violet." -Bergen, 1896

Bees Visiting Flowers

"Bees visiting flowers. At the left, a bumblebee on the flower of the dead nettle; below, a similar…

"Two flowers of common sage, one of them visited by a bee." -Bergen, 1896

Common Sage

"Two flowers of common sage, one of them visited by a bee." -Bergen, 1896

"Dimorphous flowers of the primrose. I, a long-styled flower; II, a short-styled one." -Bergen, 1896

Primrose Flowers

"Dimorphous flowers of the primrose. I, a long-styled flower; II, a short-styled one." -Bergen, 1896

"A violet with cleistogamous flowers. The objects which look like flower-buds are cleistogamous flowers in various stages of development. The pods are the fruit of similar flowers. The plant is represented as it appears in late July or August, after the ordinary flowers have disappeared." -Bergen, 1896

Violet

"A violet with cleistogamous flowers. The objects which look like flower-buds are cleistogamous flowers…

"Axillary and solitary flowers of pimpernel." -Bergen, 1896

Pimpernel Flowers

"Axillary and solitary flowers of pimpernel." -Bergen, 1896

"Raceme of common red currant. p, peduncle; p', pedicel; br, bract." -Bergen, 1896

Redcurrant Raceme

"Raceme of common red currant. p, peduncle; p', pedicel; br, bract." -Bergen, 1896

"Simple umbel of cherry." -Bergen, 1896

Cherry Umbel

"Simple umbel of cherry." -Bergen, 1896

"Catkins of willow. A, staminate flowers; B, pistillate flowers." -Bergen, 1896

Willow Catkin

"Catkins of willow. A, staminate flowers; B, pistillate flowers." -Bergen, 1896

"Spike of plantain." -Bergen, 1896

Plantain Spike

"Spike of plantain." -Bergen, 1896

"Head of yarrow. A, top view; B, lengthwise section. re, receptacle; i, involucre; r, ray-flowers; d, disk-flowers; c, corolla; s, stigma; ch, chaff, or bracts of receptacle." -Bergen, 1896

Yarrow

"Head of yarrow. A, top view; B, lengthwise section. re, receptacle; i, involucre; r, ray-flowers; d,…

"Panicle of oat." -Bergen, 1896

Oat Panicle

"Panicle of oat." -Bergen, 1896

"Diagrams of inflorescence. A, panicle; B, raceme; C, spike; D, head; E, umbel." -Bergen, 1896

Inflorescence

"Diagrams of inflorescence. A, panicle; B, raceme; C, spike; D, head; E, umbel." -Bergen, 1896

"Compound cyme of mouse-ear chickweed. t, the terminal (oldest) flower." -Bergen, 1896

Mouse-Ear Chickweed

"Compound cyme of mouse-ear chickweed. t, the terminal (oldest) flower." -Bergen, 1896

"Diagram of inflorescence of a grass. g, sterile glumes; P1, a flowering glume; P2, a scaly bract (palea); e, transparent scales (lodicules) at the base of the flower; B, the flower." -Bergen, 1896

Grass Inflorescence

"Diagram of inflorescence of a grass. g, sterile glumes; P1, a flowering glume; P2, a scaly bract (palea);…

"Inflorescence, flower, and seed, of a sedge. (Great Bulrush, Scirpus lacustris.) A, magnified flower, surrounded by perianth of hypogynous bristles; B, the seed; C, section of the seed, showing the small embryo enclosed in the base of the endosperm." -Bergen, 1896

Sedge

"Inflorescence, flower, and seed, of a sedge. (Great Bulrush, Scirpus lacustris.) A, magnified flower,…

"Alnus glutinosa. A, a flowering twig; s, staminate catkins; p, pistillate catkins; B, a group of staminate flowers, enlarged; C, two pistillate flowers, enlarged." -Bergen, 1896

Alder Flowers

"Alnus glutinosa. A, a flowering twig; s, staminate catkins; p, pistillate catkins; B, a group of staminate…

"Ulmus campestris. A, a flowering twig; B, a flower; C, longitudinal section of a flower; D, a fruit." -Bergen, 1896

Elm Flowers

"Ulmus campestris. A, a flowering twig; B, a flower; C, longitudinal section of a flower; D, a fruit."…

"Euphorbia corollata. A, flower-cluster with involucre, the whole appearing like a single flower; B, a single staminate flower; C, immature fertile flower, as seen after the removal of the sterile flowers; i, involucre; s, stigmas." -Bergen, 1896

Flowering Spurge

"Euphorbia corollata. A, flower-cluster with involucre, the whole appearing like a single flower; B,…

"Begonia Flowers. A, staminate flower; B, pistillate flower; C, twisted stigmas, enlarged; D, cross-section of ovary; o, ovary; s, sepals; p, petals." -Bergen, 1896

Begonia

"Begonia Flowers. A, staminate flower; B, pistillate flower; C, twisted stigmas, enlarged; D, cross-section…

"Flower and fruit of Umbelliferae. A, flower of Foeniculum; B, fruit of Heracleum; C, fruit of Heracleum, cross-section; o (in A), ovary; d, disk; sg, stigma; s, stamens; o (in B, and C), oil-tubes; r, ribs. A, B, and C all enlarged." -Bergen, 1896

Umbelliferae

"Flower and fruit of Umbelliferae. A, flower of Foeniculum; B, fruit of Heracleum; C, fruit of Heracleum,…

"Flowers of plantain (Plantago), enlarged. A, earlier stage, pistil mature, stamens not yet appearing outside the corolla. B, later stage, pistil withered, stamens mature." -Bergen, 1896

Plantain Flowers

"Flowers of plantain (Plantago), enlarged. A, earlier stage, pistil mature, stamens not yet appearing…

"Flower-cluster of bachelor's button (Centaurea Cyanus)." -Bergen, 1896

Cornflower

"Flower-cluster of bachelor's button (Centaurea Cyanus)." -Bergen, 1896

"Flower-cluster of yarrow (Achillea Millefolium). A, head seen from above; B, longitudinal section; re, receptacle; ch, chaff; i, involucre; r, ray-flowers; d, disk-flowers; c, corolla; s, stigma." -Bergen, 1896

Yarrow

"Flower-cluster of yarrow (Achillea Millefolium). A, head seen from above; B, longitudinal section;…

The carnivorous plant, the butterwort, of the genus Pinguicula.

Butterwort

The carnivorous plant, the butterwort, of the genus Pinguicula.

Camellia, a flowering plant of the Theaceae family.

Camellia

Camellia, a flowering plant of the Theaceae family.

A branch of the camphor tree, Cinnamomum camphora.

Camphor Tree Branch

A branch of the camphor tree, Cinnamomum camphora.

The carnation flower (Dianthus caryophyllus).

Carnation

The carnation flower (Dianthus caryophyllus).