"Bixa orellana. 1. a pistil and two stamens; 2. a cross section of the ovary; 3. a ripe fruit. 4. a cross section of a seed." -Lindley, 1853

Achiote

"Bixa orellana. 1. a pistil and two stamens; 2. a cross section of the ovary; 3. a ripe fruit. 4. a…

An illustration of an acorn.

Acorn

An illustration of an acorn.

A squirrel sitting on a branch of a tree looking upon various addition problems.

Addition Tree

A squirrel sitting on a branch of a tree looking upon various addition problems.

"Æsculus Hippocastanum (a, flower; b, seed; c, seed cut longitudinally."-Whitney, 1902

Aesculus

"Æsculus Hippocastanum (a, flower; b, seed; c, seed cut longitudinally."-Whitney, 1902

An illustration of an Agathis branch. The genus Agathis, commonly known as kauri or dammar, is a relatively small genus of 21 species of evergreen trees in the very ancient Araucariaceae family of conifers. While initially widespread during the Jurassic period they are now found only in small areas of the southern hemisphere. The trees have characteristically very large trunks and little or no branching for some way up. Young trees are normally conical in shape, only upon maturity does the crown become more rounded or irregularly shaped.

Agathis Branch

An illustration of an Agathis branch. The genus Agathis, commonly known as kauri or dammar, is a relatively…

Marlea begonifolia or Alangium chinense is an evergreen tree native in China used for its medicinal purposes.

Alangium

Marlea begonifolia or Alangium chinense is an evergreen tree native in China used for its medicinal…

Also known as Salix alaxensis. The branch of an Alaska Willow tree, a species of willow.

Branch of Alaska Willow

Also known as Salix alaxensis. The branch of an Alaska Willow tree, a species of willow.

An illustration of an alder branch.

Alder Branch

An illustration of an alder branch.

Also known as Castanea pumila. The branch of an Allegheny Chinkapin tree, native to the eastern United States.

Branch of Allegheny Chinkapin

Also known as Castanea pumila. The branch of an Allegheny Chinkapin tree, native to the eastern United…

The fruit of the small, deciduous almond tree.

Almond

The fruit of the small, deciduous almond tree.

"A genus of the natural orer Rosaceae, sub-order Amygdaleae or Drupaceae, consisting of trees or shrubs, distinguished by the coarsely furrowed and wrinkled shell of the drupe, and by the young leaves being conduplicate, or having their sides folded together." — Chambers' Encyclopedia, 1875

Almond Tree

"A genus of the natural orer Rosaceae, sub-order Amygdaleae or Drupaceae, consisting of trees or shrubs,…

The almond is native to Iran, from northwestern Saudi Arabia, north through western Jordan, Israel, Lebanon, western Syria, to southern Turkey. It is a small deciduous tree, growing to between 4 and 10 meters in height, with a trunk of up to 30 centimeters in diameter. The young shoots are green at first, becoming purplish where exposed to sunlight, then grey in their second year. The leaves are 1 cm long and 1.2–4 cm broad, with a serrated margin and a 2.5 cm petiole. The flowers are white or pale pink, 3–5 cm diameter with five petals, produced singly or in pairs before the leaves in early spring. The fruit is a drupe 3.5–6 cm long, with a downy outer coat. The outer covering or exocarp, (fleshy in other members of Prunus such as the plum and cherry), is instead a leathery grey-green coating called the hull, which contains inside a hard shell, and the edible seed, commonly called a nut in culinary terms. Generally, one seed is present, but occasionally there are two. In botanical terms, an almond is not a true nut. The reticulated hard woody shell (like the outside of a peach pit) surrounding the edible seed is called the endocarp. The fruit is mature in the autumn, 7–8 months after flowering.

Almond Tree and Fruit

The almond is native to Iran, from northwestern Saudi Arabia, north through western Jordan, Israel,…

The branch of an Alnus oregona, a species of alder tree.

Branch of Alnus Oregona

The branch of an Alnus oregona, a species of alder tree.

The branch of an Alnus sitchensis, a species of Alder tree.

Branch of Alnus Sitchensis

The branch of an Alnus sitchensis, a species of Alder tree.

Also known as Larix lyallii. A species of larch native to northwestern North America.

Alpine Larch Pine Cone

Also known as Larix lyallii. A species of larch native to northwestern North America.

Amelanchier, also known as shadbush, serviceberry, sarvisberry, juneberry, Saskatoon, shadblow, shadwood, sugarplum, and wild-plum, is a genus of about 20 species of shrubs and small deciduous trees in the Rosaceae (Rose family). The genus is native to temperate regions of the Northern Hemisphere, growing primarily in early successional habitats. It is most diverse taxonomically in North America, especially in the northern United States and southern Canada, and is native to every state of the United States except Hawaii. Two species also occur in Asia, and one in Europe. These plants are valued horticulturally, and their fruits are important to wildlife.

Amelanchier

Amelanchier, also known as shadbush, serviceberry, sarvisberry, juneberry, Saskatoon, shadblow, shadwood,…

The branch of an Amelanchier obovalis tree, native to North America.

Branch of Amelanchier Obovalis

The branch of an Amelanchier obovalis tree, native to North America.

Also known as Castanea dentata. The branch of an American Chestnut tree, native to eastern North America.

Branch of American Chestnut

Also known as Castanea dentata. The branch of an American Chestnut tree, native to eastern North America.

Also known as Ulmus americana. The branch of the American Elm, native to eastern North America.

Branch of American Elm

Also known as Ulmus americana. The branch of the American Elm, native to eastern North America.

Also known as Ostrya virginiana. The branch of an American Hophornbeam, a species of Ostrya native to eastern North America.

Branch of American Hophornbeam

Also known as Ostrya virginiana. The branch of an American Hophornbeam, a species of Ostrya native to…

Also known as Carpinus caroliniana. The branch of an American Hornbeam, native to eastern North America.

Branch of American Hornbeam

Also known as Carpinus caroliniana. The branch of an American Hornbeam, native to eastern North America.

American linden, showing wire guard.

American linden, showing wire guard.

American linden, showing wire guard.

Also known as Sorbus americana. The branch of an American Mountain-Ash tree, native to northeastern North America.

Branch of American Mountain-Ash

Also known as Sorbus americana. The branch of an American Mountain-Ash tree, native to northeastern…

Also known as Liquidambar styraciflua. The branch of an American Sweetgum tree, native to eastern North America.

Branch of American Sweetgum

Also known as Liquidambar styraciflua. The branch of an American Sweetgum tree, native to eastern North…

Also known as Platanus occidentalis. The branch of an American Sycamore tree, native throughout the central and eastern parts of the United States.

Branch of American Sycamore

Also known as Platanus occidentalis. The branch of an American Sycamore tree, native throughout the…

Also known as Salix discolor. The branch of an American Willow, native throughout North America.

Branch of America Willow

Also known as Salix discolor. The branch of an American Willow, native throughout North America.

The image depicts the flower and portion of a leaf of the Pitcairnia andreana. The petals are yellow at the tip with red at the bottom.

Pitcairnia Andreana

The image depicts the flower and portion of a leaf of the Pitcairnia andreana. The petals are yellow…

A mammal on a tree branch.

Animal in tree

A mammal on a tree branch.

The apple is a fruit tree of the Rosaceae family.

Apple

The apple is a fruit tree of the Rosaceae family.

The blossom of the well-known apple tree.

Apple-blossom

The blossom of the well-known apple tree.

Aqueduct through a wooded area.

Aqueduct Near the Battle-Field of Chapultepec

Aqueduct through a wooded area.

"Aquilaria Agallochum. 1. a flower; 2. the same split open; 3. a section of the ovary." -Lindley, 1853

Aquilaria

"Aquilaria Agallochum. 1. a flower; 2. the same split open; 3. a section of the ovary." -Lindley, 1853

A group of trees or shrubs native to North America and Europe.

Ar'butus

A group of trees or shrubs native to North America and Europe.

The araucaria excelsa is commonly known as the Norfolk Island Pine. The leaves are sharply pointed, also known as awl-shaped. The leaves are bright green and densely pakced.

Araucaria Excelsa Tree

The araucaria excelsa is commonly known as the Norfolk Island Pine. The leaves are sharply pointed,…

Araucaria Imbricata is commonly known as the Monkey Puzzle. This tree grows between fifty and one hundred feet tall.

Araucaria Imbricata Tree

Araucaria Imbricata is commonly known as the Monkey Puzzle. This tree grows between fifty and one hundred…

"A genus of plants of the natural order Coniferae, allied to the cypress, and consisting of evergreen trees and shrubs with compressed or flattened branchlets-small, scale-like, imbricated leaves-and monaecious flowers, which have 4-celled anthers, and the scales of the strobiles with two upright ovules." — Chambers' Encyclopedia, 1875

Arbor Vitae

"A genus of plants of the natural order Coniferae, allied to the cypress, and consisting of evergreen…

Also known as Alnus oblongifolia. The branch of an Arizona Alder tree, native to southwestern United States and Mexico.

Branch of Arizona Alder

Also known as Alnus oblongifolia. The branch of an Arizona Alder tree, native to southwestern United…

Also known as Cupressus arizonica. A species of cypress found in the southwest of North America.

Branch of Arizona Cypress

Also known as Cupressus arizonica. A species of cypress found in the southwest of North America.

Also known as Pinus arizonica. The pine cone of an Arizona Pine tree.

Pine Cone of Arizona Pine

Also known as Pinus arizonica. The pine cone of an Arizona Pine tree.

Also known as Vauquelinia californica. The branch of an Arizona Rosewood tree, native to the southwestern United States.

Branch of Arizona Rosewood

Also known as Vauquelinia californica. The branch of an Arizona Rosewood tree, native to the southwestern…

Also known as Platanus wrightii. The branch of an Arizona Sycamore, native to Arizona and New Mexico.

Branch of Arizona Sycamore

Also known as Platanus wrightii. The branch of an Arizona Sycamore, native to Arizona and New Mexico.

Also known as Quercus arizonica. The branch of an Arizona White Oak, native to the southwest United States.

Branch of Arizona White Oak

Also known as Quercus arizonica. The branch of an Arizona White Oak, native to the southwest United…

Also known as Salix lasiolepis. The branch of an Arroyo Willow tree, native to western and southwestern North America.

Branch of Arroyo Willow

Also known as Salix lasiolepis. The branch of an Arroyo Willow tree, native to western and southwestern…

"A tree which grows plentifully in Europe and in Siberia. It is a native of Britain, and is frequent in Scotland, where it is found even at an elevation of 1500 feet above the sea. It has recieved the specific name tremula, from the readiness with which its leaves are thrown into a tremulous motion by the slightest breath of wind. a, a portion of a branch with catkins; b, do., with leaves." — Chambers' Encyclopedia, 1875

Aspen

"A tree which grows plentifully in Europe and in Siberia. It is a native of Britain, and is frequent…

The female flowers of a catkin from the Common Aspen (Populus tremula).

Common Aspen

The female flowers of a catkin from the Common Aspen (Populus tremula).

Also known as Populus tremula. A medium-sized tree growing up to 10-25 meters tall.

Aspen

Also known as Populus tremula. A medium-sized tree growing up to 10-25 meters tall.

"A genus of Palms, of which about sixeen species are known, natives of tropical America, remarkable for the abundance of acute and formidable spines, in some cases, a foot long, with which almost every part- stem, leaves, spathe, and fruit-stalk-is armed." — Chambers' Encyclopedia, 1875

Astrocaryum

"A genus of Palms, of which about sixeen species are known, natives of tropical America, remarkable…

Also known as Chamaecyparis thyoides. Native to the eastern part of the United States.

Branch of Atlantic White Cypress

Also known as Chamaecyparis thyoides. Native to the eastern part of the United States.

An image of a bald cypress, in pyramidal cultivated form. It is otherwise known as taxodium distichum, and is native to the southeastern United States.

Bald Cypress in Cultivated Form

An image of a bald cypress, in pyramidal cultivated form. It is otherwise known as taxodium distichum,…

An image of a bald cypress in swamp form, with aerating roots, or knees. It is otherwise known as taxodium distichum, and is native to the southeastern United States.

Bald Cypress in Swamp Form

An image of a bald cypress in swamp form, with aerating roots, or knees. It is otherwise known as taxodium…

Also known as Taxodium distichum. A species of conifer native to the southeastern United States.

Pine Cone of Bald Cypress

Also known as Taxodium distichum. A species of conifer native to the southeastern United States.

Also known as Abies balsamea. A North American fir, generally found in most of the eastern and central areas of the United States and Canada.

Pine Cone of Balsam Fir

Also known as Abies balsamea. A North American fir, generally found in most of the eastern and central…

"A genus of grasses, of which most of the species attain a great size, many of them 20 or 30 feet, some 70 or 100 feet in height. The species are numerous, and are found in tropical and subtropical regions, both of the eastern and western hemispheres. They are of great importance to the inhabitants of the countries in which they grow." — Chambers' Encyclopedia, 1875

Bamboo

"A genus of grasses, of which most of the species attain a great size, many of them 20 or 30 feet, some…

The typical representation of banana on a topographical map.

Banana

The typical representation of banana on a topographical map.

An illustration of a large banana plant. Banana is the common name for a fruit and also the herbaceous plants of the genus Musa which produce this commonly eaten fruit. They are native to the tropical region of Southeast Asia. Bananas are likely to have been first domesticated in Papua New Guinea. Today, they are cultivated throughout the tropics.

Banana Plant

An illustration of a large banana plant. Banana is the common name for a fruit and also the herbaceous…

"The Banyan Tree is a species of the genus ficus. It is regarded as a sacred tree by the Hindus. Its branches produce long shoots, or aerial roots, which descend to the ground and penetrate the soil; so that, in course of time, a single tree becomes a vast umbrageous tent, supported by numerous columns."—(Charles Leonard-Stuart, 1911)

Banyan Tree

"The Banyan Tree is a species of the genus ficus. It is regarded as a sacred tree by the Hindus. Its…

"This tree, a native of India, is remarkable for its vast branches. It is a species of fig; has ovate, heart-shaped, entire leaves, about five or six inches long, and produces a fruit of a rich scarlet, not larger than a cherry, growing in pairs from the axils of the leaves." -Lupton

Banyan Tree

"This tree, a native of India, is remarkable for its vast branches. It is a species of fig; has ovate,…

The outside covering of a tree; the rind.

Bark

The outside covering of a tree; the rind.

It is a slow-growing long-lived tree, hard to transplant because of its long taproot, and subject to insect damage.

Shell-Bark Hickory

It is a slow-growing long-lived tree, hard to transplant because of its long taproot, and subject to…

"The bark lies immediately beneath the epidermis. It consists of several layers. In the early state it is cellular, and is exactly like the pith with which it is in contact; but by the production of vessels and woody fiber, they are separated and become very different in appearance and constitution. The bark consists of two portions, the cellular and vascular, the latter of which is called liber, and the inner portion of the bark."—Darby, 1855

The Bark

"The bark lies immediately beneath the epidermis. It consists of several layers. In the early state…