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An order of flowering plants, division Magnoliophyta (Angiospermae), subclass Commelinidae of the class Liliopsida (monocotyledons). The order consists of the single family Eriocaulaceae, with about 1200 species. The Eriocaulales are Commelinidae…

Volatile, fragrant oils obtained from plants. Essential oils are distinguished from those known as fixed oils, which are mainly triglycerides of fatty acids. Essential oils have been obtained from thousands of plants (Fig. 1) and are designated and…

The study of utilization of fungi by common people, as food or medicine, or in crafts, stories, or rituals. Ethnomycology is a subfield of ethnobotany (although, strictly speaking, fungi are not plants) or ethnobiology. Originally, emphasis was on…

A phytohormone (plant hormone) that is an important signaling molecule involved in many plant processes, including, but not limited to, abscission (the physiological process promoted by abscisic acid whereby plants shed a part), leaf and flower…

A large and important Australian forest tree, including about 700 species in the family Myrtaceae. Eucalyptus trees (eucalypts; genus Eucalyptus) occur throughout Australia and are particularly prevalent in eastern areas of the continent. However,…

An order of flowering plants, division Magnoliophyta (Angiospermae), in the subclass Hamamelidae of the class Magnoliopsida (dicotyledons). The order consists of a single family, genus, and species, Eucommia ulmoides, of China. It is a simple-leaved…

One of the two major types of flowering plants (angiosperms), characterized by possession of three apertures in their pollen; the other major type is magnoliids. Although this difference in pollen development and form has been known for a long time,…

An informal set of flowering plant orders that contains Laurales, Magnoliales, Piperales, and Winterales, plus the monocotyledons, and in total contains roughly one-third of angiosperm species. Formerly, many have equated this group (minus the…

An order of flowering plants, division Magnoliophyta (Angiospermae), in the subclass Rosidae of the class Magnoliopsida (dicotyledons). The order consists of the large family Euphorbiaceae (about 7500 species) and 3 small satellite families which…

A small class of nonmotile, photosynthetic, unicellular algae, segregated from the class Xanthophyceae (Tribophyceae) on the basis of cytological, ultrastructural, and biochemical features of the vegetative cell and zoospore. Because of their lack…

Plants that retain their green foliage throughout the year. Popularly, needle-leaved trees (pine, fir, juniper, spruce) and certain broad-leaved shrubs (rhododendron, laurel) are called evergreens. In warm regions many broad-leaved trees (magnolia,…

An order of flowering plants, division Magnoliophyta (Angiospermae), in the subclass Rosidae of the class Magnoliopsida (dicotyledons). The order consists of three closely related families (Mimosaceae, Caesalpiniaceae, Fabaceae) collectively called…

An order of flowering plants, division Magnoliophyta (Angiospermae), in the superorder Rosanae (eudicotyledons). The order Fagales consists of 8 families: Betulaceae, Casuarinaceae, Fagaceae, Juglandaceae, Myricaceae, Nothofagaceae, Rhoipteleaceae,…

Foeniculum vulgare, a culinary herb of the parsley family (Apiaceae). Fennel is grown for the dried, ripe fruits or seeds, which are used as a spice in breads, pickles, liqueurs, and meat sauces and dishes. Although similar in odor to anise, fennel…

A process in many plants resulting in the fusion of a female gamete and a male gamete to form a single cell, the zygote. Both vegetative (asexual) reproduction and sexual reproduction occur in plants. Reproduction by gamete fusion is very different…

Plants grown for their fibrous material, which is used for many commercial purposes and for home industry. Many plants are grown as fiber crops because of their content or yield of fibrous material, which is used in the manufacture of textiles,…

A species of deciduous tree, Ficus carica, of the mulberry family (Moraceae). The fig tree is of southwest Asian origin and is now cultivated in the subtropical regions of the world for its edible fruit, especially in Asia, Africa, Europe, and the…

Any tree of the genus Abies, of the pine family, characterized by erect cones, the absence of resin canals in the wood but with many in the bark, and flattened needlelike leaves that lack definite stalks. Fir leaves usually have two white lines on…

An order of the true mosses (subclass Bryidae) consisting of a single family, the Fissidentaceae, and about 800 species in the genus Fissidens plus a few others distributed in four or five segregate genera. Fissidens is the largest genus of…

A large category of natural plant products that derive from γ-pyrone (1). All flavonoid compounds, which are derived from either 2-phenylbenzopyrone (2) or 3-phenylbenzopyrone (3), can be classified into 10 groups (Fig. 1): chalcones,…

A hormone-like protein that controls when a plant will flower in response to the changes in day length associated with the different seasons. Florigen is produced in leaves, where changes in day length are perceived, and migrates through the phloem…

A higher plant's sexual apparatus in the aggregate, including the parts that produce sex cells and closely associated attractive and protective parts (Fig. 1). “Flower” has been used broadly enough by some botanists to include the reproductive…

The application of plant science for purposes of civil or criminal law. Forensic botany has opened aspects of the field of botany to novel avenues within criminal investigations. Today, several subdisciplines of plant science are being applied…

The organic remains, traces, or imprint of seeds and fruits. Seeds, ovules containing a fertilized egg and ready to be shed from the plant, are reproductive organs characteristic of both gymnospermous and angiospermous plants. In angiosperms…

A matured carpel or group of carpels (the basic units of the gynoecium or female part of the flower) with or without seeds, and with or without other floral or shoot parts (accessory structures) united to the carpel or carpels. Carpology is the…

Any edible fruit borne on a tree. Tree fruits include temperate, subtropical, and tropical zone species. Most temperate-zone fruit trees are deciduous, that is, they lose their leaves in the autumn. They are grown principally in regions protected…

A large and diverse order of conspicuous brown algae (class Phaeophyceae), including such well-known seaweeds as Fucus and Sargassum. Definitive features of members of the Fucales include apical growth, production of sex organs in cavities, and a…

An order of the true mosses (subclass Bryidae). The Funariales, often annuals or biennials and sometimes ephemeral, are for the most part characterized by a uniformity of gametophytic structure in contrast to a variability of sporophytic characters…

The application of biotechnological techniques utilizing fungi for agricultural purposes. Fungal biotechnology is applied in agriculture to promote plant vigor, to increase yields, and to reduce impacts of plant diseases, weeds, or invertebrate…

The study of the entire genetic content of fungal organisms. Fungal genomics is a discipline that developed out of advances in automated nucleic acid sequencing and computer technology. In the case of fungal genomics, the objective of the DNA…

The classification of Fungi based on phylogenetic (evolutionary) relationships. Fungi constitute one of the major branches of the tree of life. There are about 100,000 described species in the Fungi, but it has been estimated that there are as many…

An order of flowering plants (angiosperms) in the euasterid I group of the asterid eudicotyledons. The order consists of five families and approximately 17,500 species. The circumscription of Gentianales has been widened to include Rubiaceae,…

An order of flowering plants, division Magnoliophyta (Angiospermae), in the superorder Rosanae (eudicotyledons). The order Geraniales consists of 6 families (Francoaceae, Geraniaceae, Greyiaceae, Ledocarpaceae, Melianthaceae, and Vivianiaceae), 15…

Members of a family of diterpenoid carboxylic acids, most of which possess the ent-gibberellane or ent-20-norgibberellane skeletons. Gibberellins occur in some fungal and bacterial species and in all higher plants, in which certain members function…

An order of gymnosperms in the class Ginkgoopsida with only one extant species, Ginkgo biloba (the maidenhair tree). Ginkgo biloba (Fig. 1), also referred to as the ginkgo tree, is native to China. It is cultivated as a shade tree in cities around…

A class of largely extinct gymnosperms. The class Ginkgoopsida contains one order of seed plants: Ginkgoales. Representatives of the Ginkgoales lived predominantly from the Triassic into the Cretaceous, with one species, Ginkgo biloba, persisting to…

The common name for plants of the genus Vitis characterized by climbing stems and grown for the edible, pulpy berries. The common grapevine Vitis vinifera (Fig. 1) has intermittent forked tendrils, a bark that sheds, a diaphragm at the node, and…

Citrus paradisi, an evergreen tree belonging to the order Sapindales and having a well-rounded top cultivated for its edible citrus fruit, which is large, globose, and characterized by a yellow rind and white, pink, or red pulp. The grapefruit…

Members of the family Poaceae (Gramineae) cultivated as forage and grain for consumption. The grasses are the most useful of all the plants that cover the Earth. The cereal grass crops [wheat (Fig. 1), rice, corn (maize), rye, barley, oats, sorghum,…

A glass- or plastic-enclosed structure that is used to grow plants under protected conditions. Greenhouses (also known as glasshouses) are transparent, enclosed, climate-controlled structures (Fig. 1) in which young, tender, or out-of-season plants…

Morphologically distinct cells that are found in the epidermis of terrestrial plant shoots and that function in regulating stoma size. Each pair of specialized guard cells circumscribes and defines a microscopic hole called a stoma (the plural form…

A genus of marine, benthic, green algae (division Chlorophyta) belonging to the family Halimedaceae in the order Bryopsidales. Halimeda plants are attached by a holdfast, generally several centimeters high, and consist of calcareous segments…

A small subclass of the class Magnoliopsida (dicotyledons) in the division Magnoliophyta (Angiospermae), the flowering plants, consisting of 11 orders (Trochodendrales, Hamamelidales, Daphniphyllales, Didymelales, Eucommiales, Urticales,…

A small order of flowering plants [subclass Hamamelidae, class Magnoliopsida (dicotyledons), division Magnoliophyta (Angiospermae)], but whose members are now more typically redistributed across various plant orders. The order Hamamelidales has been…

The genus Tsuga of the pine family, characterized by flattened needles with two white lines beneath the needlelike leaves, which have distinct short stalks. The cones of hemlock are small and pendent (see illustration). Eastern hemlock (Tsuga…

An agave plant, Agave fourcroydes, and the fiber obtained from its leaves. Henequen is produced only in Mexico, Cuba, and El Salvador. It is a hard plant fiber and is used to make rope, twine, and cord. Henequen is sometimes incorrectly called…

A class of lower green plants called liverworts that belong to the division Bryophyta. The class is divided into approximately 225 genera and 8500 species. Although there is a great diversity of external form, most of the gametophytes…

A collection of pressed and dried plant specimens, and a description of when, where, and by whom they were collected, arranged in a systematic manner, and serving as a permanent physical record of the occurrence of an individual plant at a specific…

Any species of the genus Carya, formerly known botanically as Hicoria. Hickories are mostly tall forest trees characterized by strong, terminal, scaly winter buds; pinnately compound leaves (see illustration); solid piths (not chambered); and fruit…

Any species of the genus Ilex. The American species of holly (Ilex opaca) attains a maximum height of 40–50 ft (12–15 m) and has evergreen leaves. American holly grows naturally in the eastern and southeastern United States, close to the Atlantic…