4. Cupressus Linnaeus, Sp. Pl. 2: 1002. 1753; Gen. Pl. ed. 5, 435, 1754.
Cypress [Latin name of C . sempervirens ]
James E. Eckenwalder
Trees or large shrubs evergreen. Branchlets terete or quadrangular, in decussate arrays (or partially comblike in Cupressus macnabiana ). Leaves opposite in 4 ranks. Adult leaves appressed to divergent, scalelike, rhomboid, free portion of long-shoot leaves to 4 mm; abaxial gland present or absent. Pollen cones with 4--10 pairs of sporophylls, each sporophyll with 3--10 pollen sacs. Seed cones maturing in 1--2 years, generally persisting closed many years or until opened by fire, globose or oblong, 1--4 cm; scales persistent, 3--6 pairs, valvate, peltate, thick and woody. Seeds 5--20 per scale, lenticular or faceted, narrowly 2-winged; cotyledons 2--5. x = 11.
Species 10--26 (7 in the flora): warm north temperate regions.
The genus Cupressus in North America consists mainly of small, disjunct, relictual populations, many differing from related populations in color and size of leaves and seeds, activity of leaf glands, glaucousness of various parts, form of growth, and characteristics of bark. Disagreements on the number and rank of taxa reflect these variations. This treatment, with seven taxa, approaches the more conservative end of a spectrum; anywhere from 6 to 15 taxa---species, subspecies, and varieties---might be accepted in the flora. The taxonomy of the genus would benefit from detailed studies of variation in and among populations (cf. J. F. Goggans and C. E. Posey 1968).
The Mediterranean Cupressus sempervirens Linnaeus, usually with a fastigiate habit, is commonly cultivated in California, often away from dwellings, but it does not appear to have become naturalized. Other introduced Eurasian and Mexican species are clearly associated with cultivated landscapes.
SELECTED REFERENCES
Goggans, J. F. and C. E. Posey. 1968. Variation in seeds and ovulate cones of some species and varieties of Cupressus. Circ. Agric. Exp. Sta., Alabama 160: 1--23. Little, E. L. Jr. 1966. Varietal transfers in Cupressus and Chamaecyparis. Madroño 18: 161--167. Little, E. L. Jr. 1970. Names of New World cypresses (Cupressus). Phytologia 20: 429--445. Silba, J. 1981. Revision of Cupressus L. (Cupressaceae). Phytologia 49: 390--399. Wolf, C. B. 1948. Taxonomic and distributional studies of the New World cypresses. Aliso 1: 1--250.
