Vascular Flora of the Southeastern United States
Hardin, Massey, Radford, Thieret, eds.
Copyright - James W. Hardin, Ph. D., 1998, 1999. All Rights Reserved.
3. CUPRESSACEAE THE CYPRESS FAMILY
Evergreen or deciduous, monoecious or dioecious, aromatic, resinous trees or shrubs. Leaves alternate, opposite and decussate or in whorls of 3 or 4, subulate (awn-shaped) and spreading, or scale-like and divergent or appressed and imbricate, and often with a resinous gland on the abaxial (exposed) surface below the apex. Pollen cones small, oblong, ovoid, or cylindrical, either solitary, in clusters of 2-5, or numerous in terminal racemes or panicles. Seed cones woody, leathery, or semi-fleshy, composed of fused scale-bract complexes, each thin and flattened and imbricate or peltate and connate; seeds laterally winged or wingless.
The Taxodiaceae (Redwood Family) and Cupressaceae s. str. (Cypress Family) have long been recognized as distinct. Recent studies, however, have shown that the monophylitic Cupressaceae s. str. are derived from within the old Taxodiaceae. Therefore, a much more realistic phylogenetic classification combines them into the Cupressaceae s. lat.
- 1. Leaves alternate; leafy branches annually deciduous; pollen cones many in drooping racemes or panicles.....1. Taxodium.
- 1. Leaves opposite or whorled; evergreen; pollen cones solitary or in clusters of 2-5.
- 2 Branchlets and leafy twigs more or less flattened into one plane, forming flat sprays or fronds.
- 3 Branchlets and twigs obviously flattened, twigs with leaves dark green when fresh, 2-3 mm wide the facial and lateral leaves different; seed cones oblong, cone bracts thin, flattened and imbricate..... 2. Thuja.
- 3 Branchlets and twigs slightly flattened, twigs with leaves usually glaucous when fresh, 2 mm or less wide, the facial and lateral leaves similar; seed cones globose, cone scale-bracts peltate, valvate..... 3. Chamaecyparis.
- 2 Branchlets and leafy twigs oriented in various planes, not flattened into sprays.
- 4 Scale leaves in whorls of 3; seed cones woody; seeds winged..... 4. Callitris.
- 4 Scale leaves opposite and decussate or lacking; seed cone semi-fleshy and berry-like; seeds wingless..... 5. Juniperus.