Cupressaceae Gray

Trees or shrubs evergreen (usually deciduous in Taxodium ), generally resinous and aromatic, monoecious (usually dioecious in Juniperus ). Bark fibrous and furrowed (smooth or exfoliating in plates in some Cupressus and Juniperus species). Lateral branches well developed, similar to leading shoots, twigs terete, angled, or flattened dorsiventrally (with structurally distinct lower and upper surfaces; Thuja , Calocedrus ), densely clothed by scalelike leaves or by decurrent leaf bases; longest internodes to 1 cm; buds undifferentiated and inconspicuous (except in Sequoia ). Roots fibrous to woody (bearing aboveground "knees" in Taxodium ). Leaves simple, usually persisting 3--5 years and shed with lateral shoots (cladoptosic) (shed annually in Taxodium ), alternate and spirally arranged but sometimes twisted so as to appear 2-ranked, or opposite in 4 ranks, or whorled, deltate-scalelike to linear, decurrent, sessile or petioled; adult leaves appressed or spreading, often differing between lateral and leading shoots (twigs heterophyllous), sometimes strongly dimorphic on each twig ( Thuja , Calocedrus ) with lateral scale-leaf pairs conspicuously keeled; juvenile leaves linear, flattened, spreading; often with solitary abaxial resin gland; resin canal present. Pollen cones maturing and shed annually, solitary, terminal (rarely in clusters of 2--5, axillary in Juniperus communis ; usually in terminal panicles in Taxodium ), simple, spheric to oblong; sporophylls overlapping, bearing 2--10 abaxial microsporangia (pollen sacs); pollen spheric, not winged. Seed cones maturing in 1--2 seasons, shed with short shoots or persisting indefinitely on long-lived axes (shattering at maturity in Taxodium ), compound, solitary, terminal (rarely in clusters of 2--5, axillary in Juniperus communis ); scales overlapping or abutting, fused to subtending bracts with only bract apex sometimes free; each scale-bract complex peltate, oblong or cuneate, at maturity woody or fleshy, with 1--20 erect (inverted with age in Sequoia and Sequoiadendron ), adaxial ovules. Seeds 1--20 per scale, not winged or with 2--3 symmetric or asymmetric wings; aril lacking; cotyledons 2--9.