Scientific name: Cupressus arizonica Greene 1882

Synonyms: Cupressus arizonica var. arizonica, Callitropsis arizonica (Greene) D.P.Little, Hesperocyparis arizonica (Greene) Bartel, Hesperocyparis revealiana (Silba) Silba, Neocupressus arizonica (Greene) de Laub.

Common names: Arizona cypress

Description

Tree to 28 m tall, with trunk to 2 m in diameter. Bark ridged and furrowed or smooth and peeling in flakes. Crown dense, conical, broadening with age. Branchlets four-sided, 1.3-2.3 mm in diameter, branching from all four rows of leaves. Scale leaves on branchlets 1-2 mm long, dark green or gray-green with wax, the edges minutely toothed, the back usually with a conspicuous drop of dried resin in an open gland. Pollen cones 2-5 mm long, about 2 mm wide, with (4-)5-8(-10) pairs of pollen scales, each with (three or) four to six pollen sacs. Seed cones spherical or a little elongated, (1.5-)2-3 cm long, gray or brown at maturity, often waxy before this, with three or four (to six) pairs of seed scales, each usually with a strong conical point on the face, especially on the upper scales, the surface otherwise smooth or warty. Seeds (5-)8-15(-20) per scale, (3-)4-6(-8) mm long, light to dark brown, sometimes with a thin to dense waxy coating or with resin pockets, or both. Cotyledons three to five (or six).

Southwestern North America from south-central California to northern Zacatecas (Mexico). Dry to moist woodlands and scrublands on slopes and in valleys; 750-2,400(-2,825) m. The climate is characterized by warm to hot, dry summers and winter rainfall.

Conservation Status

Red List Category & Criteria: Least Concern

Despite the threatened status of several of its varieties, which have disjunct and limited ranges, the species as a whole occurs over a huge area in the SW of North America. The nominate variety has an almost similar range (does not occur in California) and is Least Concern like the species as a whole. In montane coniferous forest, mixed broad-leaf-coniferous woodland, Pinyon-Juniper woodland, sclerophyllous scrubland ('chaparral'), and valley scrub-grassland. The altitudinal range is between 750 m and 2700 m a.s.l. Associated species in these vegetation types are Pseudotsuga menziesii, Abies concolor, Calocedrus decurrens, Pinus ponderosa, Pinus jeffreyi, Pinus arizonica, Pinus leiophylla, Pinus lambertiana, Pinus sabiniana, Pinus coulteri, Pinus cembroides, Pinus edulis, Pinus monophylla, Juniperus deppeana var. pachyphlaea, Juniperus californica, Fraxinus velutina, Quercus spp., Garrya sp., Cercocarpus sp., Platanus sp., Populus tremuloides, Salix sp. (along creeks), Rhus ovata, Fremontia californica, Yucca whippleyi, Adenostoma fasciculatum, Arctostaphylos glandulosa, Ceanothus spp., and Rhamnus sp. It is usually 'gregarious' and occurs on ridges, slopes and in canyons, sometimes in creek beds, in rocky terrain in yellow or red-brown loam, sand or gravel, or among boulders over limestone, sandstone, slate or granite. Fire hazards are the main threat, especially affecting several of the varieties with a limited distribution and/or a small and fragmented subpopulations. The species, in particular var. glabra from Arizona, has for a considerable time been cultivated in gardens and parks in Europe and the USA as an ornamental. Young trees have a naturally conical habit and several cultivars have been selected to enhance this shape; other cultivars emphasize juvenile leaf type and extreme glaucousness of foliage. This species is tolerant of draught and grows well on chalk in full sun. More protected areas should be established that contain this species, so that proper fire management can be more successfully implemented or enforced.

References

Farjon, A. (2010). A Handbook of the World's Conifers. Koninklijke Brill, Leiden.
Eckenwalder, J.E. (2009) Conifers of the World: The Complete Reference. Timber Press, Portland.
IUCN Red List of Threatened Species, International Union for Conservation of Nature and Natural Resources. Cambridge, UK /Gland, Switzerland