Families

Acanthaceae

The Acanthaceae is a family consisting about 250 genera and about 2500 species mainly of tropical shrubs, but include some temperate species.  The leaves are opposite and decussate, simple without stipules, and often have cystoliths which show up as streaks on the lamina.  The flowers are bisexual, usually irregular or two-lipped, solitary or arranged in cymes or racemes.  The ovary ripens into a capsule in which the seeds are usually bourne on small hook-like outgrowths.  The seeds have no endosperm and usually large embryos. 

Alangiaceae

This is a small, woody family of obscure affinities comprised of 2 genera and about 23 species. The leaves are simple and without stipules.  The flowers are regular, bisexual and borne in bracteolate, joined pedicels in axillary cymes.  The fruit is a drupe with a hard endocarp and usually crowned with the persistent calyx.  The seed has a fleshy endosperm. 

Anacardiaceae

This is the sumac family of flowering plants in the order Sapindales, with about 70 genera and 650 species of evergreen or deciduous trees, shrubs, and woody vines. It is native to tropical and subtropical areas of the world, but a few species occur in temperate regions. Members of the family have resin ducts in the bark, leaves usually composed of leaflets in various arrangements, flowers often with only male or female parts, and usually fleshy fruits. 

Annonaceae

The custard-apple, or annona, family, the largest family of the magnolia order (Magnoliales). According to some authorities, it contains 120 genera and 2000 species. Many species are valuable for their large, pulpy fruits, some are useful for their timber, and others are prized as ornamentals. The family consists of trees, shrubs, and woody climbers found mainly in the tropics, although a few species extend into temperate regions.  Leaves and wood are often fragrant. Leaves are simple, with smooth margins, and alternately arranged in two rows along the stems. The radially symmetrical flowers are usually bisexual. In some species, flowers are borne directly on large branches or on the trunk.  The fruit is a berry.  

Apocynaceae

The dogbane family of flowering plants of the gentian order (Gentianales), composed of more than 150 genera and about 1000 species of trees, shrubs, woody vines, and herbs, distributed primarily in tropical and subtropical areas of the world. Members of the family have milky, often poisonous juice; smooth-margined leaves; and flowers in clusters (rarely solitary). The fruit may be berrylike or fleshy but usually is a dry pod (follicle) that splits open at maturity, releasing many winged or tufted seeds.

Aquifoilaceae

This family of trees and shrubs comprises about 3 genera and 400 species.  The family is widely distributed in both temperate and tropical regions.  The leaves are leathery, sometimes evergreen and usually alternate; stipules are present but may fall soon after enlargement of the leaf.  The inconspicuous, greenish-white flowers are bisexual or unisexual.  The fruit is a berry and the seeds have copious endosperm.

Araceae

The Araceae (the aroids) is a large family of mostly herbaceous plants, with great variety in vegetative habit composed of about 110 genera and 2000 species.  The leaves are simple or compound, basal or produced on the ariel stems.  The flowers are bisexual or unisexual (with both sexes bourne on the same sapdix with the male higher than the female flowers.  On most the species, the fruit is a berry, sometimes leathery, with one to many seeds which are usually endospermic with a straight embryo.

Araliaceae

The ginseng family of flowering plants, in the order Apiales, comprises approximately 55 genera and 700 species. Most members are shrubs or trees, though there are a number of climbers and a few herbs. The family has large, usually alternate, compound leaves, five-parted flowers arranged in compound umbels (flat-topped clusters), and a berry or (rarely) a drupe (a one-seeded fruit). Several members of the family are economically important.

Aristolochiaceae

The Aristolochiaceae is a family of shrubs, lianas or herbs comprised of 400 species in 7 genera.  Leaves are alternate; spiral; flat; herbaceous, or herbaceous and membranous; petiolate; sheathing to non-sheathing; gland-dotted (pellucid punctate), or not gland-dotted; aromatic; simple.  Flowers are solitary, or aggregated in inflorescences; in cymes, or in racemes, or in spikes.  Fruit non-fleshy (usually), or fleshy (sometimes with a fleshy endocarp); dehiscent (usually), or indehiscent (rarely), or a schizocarp (Saruma).  Seeds have a straight embryo and oily endosperm.

Asclepiadaceae

The Asclepiadaceae is a fairly large family of perennial herbs, shrubs, woody climbers or trees.  It comprises about 250 genera and 1800-2000 species.  The leaves are usually opposite or whorled, rarely alternate, simple and generally entire; in some succulent taxa they are caducous or vestigial.  Minute stipules are normally present.  The flowers are regular and bisexual.  The fruit consists of a pair of follicles.  The seeds are usually flattened, ovate to oblong and bear a coma of long, silky hairs; endosperm is present and the embryo is straight.

Asteraceae (Compositae)

The Asteraceae is one of the largest families of flowering plants, with about 1100 currently accepted genera and 25000 species.  Most of its members are evergreen shrubs or sub-shrubs or perennial rhizomatous herbs, but tap-rooted or tuberous-rooted perennials and biennial trees are infrequent, as are epiphytes, and true aquatics are rare.  The leaves are alternate or opposite, rarely whorled, and without stipules.  Anatomically, Asteraceae are characterized by the presence of resin canals or latex ducts.  The fruit is one-seeded, indehiscent, nearly always dry, and is termed a cypsela.  It may be angular, rounded, variously compressed, or curved, ornamented or winged in various ways; rarely it is a drupe, with fleshy endocarp.  The seed has no endosperm and a straight embryo.

Avicenniaceae

The Avicenniaceae is a helophytic family of small mangrove trees and shrubs. It contains about 11 species in a single genus, Avicennia.  The leaves are opposite, simple and ex-stipulate. The Flowers aggregated in inflorescences; in cymes, in panicles, and in umbels. They are bracteate, small, regular, cyclic and tetracyclic. The Fruit is non-fleshy, dehiscent and a capsule.