Dioecious, more rarely monoecious, evergreen shrubs or small to large trees of very varying individual form, with leaves spreading when young, but adult individuals often with predominantly acicular or cupressoid foliage persisting for many years. The seed-bearing organs are multi-scaled cones whose cone scales become concrescent and fleshy at maturity. Shoots and fruits have a characteristic, often slightly pungent resinous, terpenoid or aromatic smell.

Monoecious, medium-sized evergreen trees of strongly columnar habit, the crown much-branched, the macronodes marking annual growth increments giving rise to strong annual whorls of branchlet systems arising typically in whorls of five. The simple linear foliage is of markedly yew-like form and remains similar throughout the tree.

Low-creeping, much-branched evergreen shrubs, with opposite and decussate pairs of small scale leaves on shoots of tetragonal sectional shape. Linearly ranked minute leaves are arrayed along shoots which have a tendency to produce markedly spear-shaped branchlet clusters. Female cones at maturity are conspicuously red and fleshy, their external aspects finely puckered, resembling the exterior of a small, mature strawberry.

Mostly dioecious (occasionally monoecious), evergreen, slow-growing, resiniferous woody shrubs or slender bushy trees, attaining moderate size and age, but with occasional members forming larger, much older and stouter trees. Of monopodial habit when young and throughout much of their life, or becoming of more or less irregular habit with maturity. The females bear scattered clusters of pendulous large fleshy-covered seeds in autumn, which are long-retained on the parent plant.

Small to scarcely medium-sized microphyllous evergreen shrub or occasionally small tree, with a rounded to irregular crown. The branch systems are short and irregular, and often adopt a sprawling drooping-tipped habit. The shoots are tightly clothed throughout exclusively with minute scale-like foliage, giving them a neatly terete appearance. The plants bear scattered and solitary few-scaled dry (i.e. non-succulent) seed cones, with scales opening widely at maturity.

Monoecious or dioecious, moderate-sized to large trees, with leaves strongly ranked in flattened, frond-like evergreen sprays of regularly pectinate and regimented arrangement on all main lateral shoots and branchlets.

Tall to extremely tall and ultimately highly majestic mostly tropical lowland rainforest trees, to 30–60+ m when mature, usually eventually with an unbranched, typically straight and clear trunk for two-thirds of more of the height of the tree. They bear a large to sometimes massive evergreen crown, typically emergent high above surrounding broadleaf rainforest canopies. The presence of fallen large, leathery, stalked multi-veined leaves, elongate–cylindrical red–brown male cones and free, winged seeds fallen from dismembering female cones, all typically shed whole to the forest floor from high tree canopies, confirms the presence of Agathis, and distinguishes Agathis from other resinifera and from surrounding broadleaves.

Moderate to tall, monoecious evergreen trees, with either densely crowded imbricate scale leaves, 2–4 mm long, in opposite and decussate pairs, or with this foliar type mixed with shoots reverting irregularly to more juvenile foliage growth.

Monoecious, evergreen, cone-bearing, small trees or shrubs with pale green to grey–green foliage, of specifically somewhat variable form. The typically much-branched slender foliage shoots give each shoot a grooved-triangular form with cylindrical joints and often rather casuarinoid appearance. The tree has a somewhat conical, tapering crown composed of multiple slender often ascending branchlets. It bears female cones of multiple generations, usually persisting conspicuously on many thicker parts of tree branchlet systems.

A small, stout, shrub-like, erect, root-parasitic miniature woody tree of meagre size, with branches clustered near the top and ascending irregularly. The whole plant is hoary. The young shoots are brilliant crimson turning wine-red to purple with age.

Medium-sized to slender and tall tropical evergreen trees, especially characterised by being one of a few resiniferous genera whose leaves are wide and ovate, with multiple sub-parallel and fine longitudinal veins. Each leaf terminates in a distinctive drip-tip.

Dioecious, evergreen, slow-growing, resiniferous woody slender trees, attaining moderate size, of monopodial habit when young but becoming of more or less gracefully irregular habit with maturity, with spreading to pendulous large sickle-shaped leaves which are conspicuously white-banded beneath. It differs from the much more common Cephalotaxus vegetatively in its larger and broader more horizontally held leaves, and reproductively in its simpler seed-bearing structures but more complexly structured male ones.

Monoecious or occasionally dioecious evergreen trees, with a typically conical, narrowly to broadly tapering crown. The bright yellow–green typically cupressoid foliage of moderately large scale leaves is held in mostly radially vertical sprays.

Medium to moderately tall, monoecious, semi-deciduous trees of imposing mature appearance in the wild, with a typically conical, tapering crown when young, becoming billowing, multi-domed and relatively open but remaining well furnished with age. The foliage is soft, blue–green and mostly winter-deciduous. The trunk bases are flared and surrounded by low but vertically ascending round-topped ascending aerophore root groupings.

Fairly fast-growing monoecious trees of fully winter-deciduous habit. When young they have a typically conical, tapering crown, long remaining symmetric and spire-like, with slender, level branches bearing masses of small, flattened, soft-textured and highly flexible bright-yellow–green leaves set oppositely in two flattened sub-pinnate ranks.

Tall to extremely tall, large to typically eventually massive, monoecious evergreen trees. The tree crowns in younger trees (for the first many centuries) are symmetric, fairly dense and well-furnished. The crowns are conical, becoming clean-trunked with age, generating thick, spongy, red–brown bark. The specimens eventually grow into the most massive known tree, of particularly substantial and imposing mature appearance in the wild.