cuyamaca cypress

Hesperocyparis stephensonii is a tree that can attain heights of 10 to 16 m (33 to 52 ft). It usually forms a spreading tree with a central leader, only slightly taller than it is wide. The tree's female cones are about 10 mm in diameter, while cone scales are normally 6–8 mm. Often, but not always, they have conspicuous umbos 3–4 mm, which are high and conical. There are normally 100-125 seeds per cone, not at all glaucous. 3-4 cotyledons are usually present. It is the only western cypress species in California to release pollen in the summertime.

The Cuyamaca Cypress only verifiably exists in the headwaters area of King Creek in the Cuyamaca Mountains of the Peninsular Ranges system, south of Cuyamaca Peak within San Diego County in extreme Southern California. Trees were reported growing as low as 3,000 feet (910 m) in elevation in 1998, but the presence of these individuals today has not been verified. Most individual trees occur at 4,500–5,100 feet (1,400–1,600 m) within the Pacific Southwest Research Station's King Creek Research Natural Area, in the Cleveland National Forest.

Conservation. It is an IUCN Red List Critically Endangered species, and a California Native Plant Society Inventory of Rare and Endangered Plants listed Seriously endangered species. The entire native (world) population of the tree was reduced down to thirty to forty individual trees by the 2003 Cedar Fire.