Hesperocyparis guadalupensis Guadalupe cypress

Guadalupe cypress, Kingscote Gardens. Sairus Patel, 22 Oct 2024

Guadalupe cypress, Kingscote Gardens. Sairus Patel, 21 May 2021

An endangered species from Guadalupe Island, off the coast of Baja California, where it was nearly driven to extinction by feral goats. Once the Mexican government eradicated the ruminants in 2006, the cypress began regenerating in the wild. It has performed spectacularly at Stanford for decades. Its smooth bark, patterned with chocolatey patches – both milk and dark – and hints of cherry, peels away in small strips that remain curled against the trunk like buff-colored cinnamon sticks. The airy bluish foliage forms a soft cloud around the trunk, the branchlets markedly finer than those of Arizona cypress.

Just south of the pond at Kingscote Gardens, a narrowly columnar tree soars upward at lawn’s edge. Another, untended and unwatered, grows north of the Arizona Garden at a path junction. Near the ground its trunk leans sharply, then straightens, allowing low branches to develop into perfectly upright trunks in their own right, perched upon the mother stem. The age of our pair is uncertain; oddly, there is neither a planting record nor any recollection of the arrival of either tree.

In a remarkable Stanford experiment in the 1930s, plant pathologist Willis Wagener tested 17 species of the cypress family, planting hundreds of trees. Among them, the 20 Guadalupe cypresses grew almost as rapidly as Monterey cypress in both height and trunk diameter and proved the most free of pests and diseases. They were not at all susceptible to the dreaded cypress canker fungus – first detected at Stanford a decade earlier and formally described by Wagener himself. He concluded that Guadalupe cypress deserved wider use.

Given Wagener’s findings on growth rate, our two specimens are likely to be of 1990s or early 2000s vintage, and not remnants of his trials. At 1146 Waverley Street in Palo Alto, one of a former pair of ‘Greenlee’s Blue Rocket’ – an upright bluish selection similar to the one at Kingscote Gardens – can be seen just inside the gate. Since Guadalupe Island lies within the California Floristic Province, it is easy to imagine ‘Greenlee’s Blue Rocket’ and other narrow cultivars as a distinctly Californian answer to the Italian cypress.