Hesperocyparis guadalupensis

(S.Watson) Bartel 2009

Common names

Taxonomic notes

Synonymy: see POWO (accessed 2023.12.16). See Hesperocyparis for a discussion of the relationship between this and other, closely related Hesperocyparis taxa in northwest Mexico and the adjacent Southwest U.S. Also see H. forbesii.

Description

Trees 12-20 m tall and up to 50 cm dbh at maturity, usually smaller in habitat, with an irregular, spreading crown. Bark exfoliating in thin plates. Branchlets slender. Leaves scale-like, opposite in 4 rows, about 1.5-2 mm long, bright green, usually lacking a glandular dot or whitish resin. Seed cones globose, 3-3.5 cm in diameter, dull brown or gray at maturity, composed of 6-10 scales with a prominent pointed tip. Seeds about 10 to a cone, dark brown and slightly bluish pruinose (Vidakovic 1991, Nearctica 2000). See García Esteban et al. (2004) for a detailed characterization of the wood anatomy.

Seeds of H. guadalupensis and H. forbesii are the same color, but seeds of C. guadalupensis have a glaucous bloom and those of C. forbesii are shiny (Wolf and Wagener 1948 in Bonner [no date]).

There are about 55,000 seeds/kg, which makes them 2-7 times as heavy as seeds of other North American species of Cupressus (Bonner [no date]).

Distribution and Ecology

Mexico: Baja California Norte: endemic to Guadalupe Island, which it shares with one other conifer, the equally rare and endangered Pinus radiata var. binata. The island is a desert with moisture chiefly provided by fogs, which limit the species' distribution on the island (Instituto Nacional de Ecología 2002). For many years the species was further and more severely limited by the grazing of goats, which reduced its population to about 3300 individuals on about 160 ha, with negligible regeneration. However, in 2005, under the leadership of Dr. Alfonso Aguirre Muñoz, the Grupo de Ecología y Conservación de Islas, A.C. succeeded in completely eradicating the goats from this large island and the trees and vegetation are now recovering (email, Aguirre Muñoz, 2012.03.01). This is an uncommon bit of good news in the generally depressing landscape of rare conifer conservation.

Data from USGS (1999).

Zone 9 (cold hardiness limit between -6.6°C and -1.1°C) (Bannister and Neuner 2001). See also Thompson et al. (1999).

Remarkable Specimens

The largest known is the Fresno, California tree pictured here; it is 21 m tall and 163 cm dbh. It is probably larger than any tree in the species' native habitat.

Ethnobotany

The species has been in cultivation since about 1879 but is not frost tolerant and does not set seed outside of habitat (Bonner [no date]), thus it is rarely used as an ornamental.

Observations

The type variety can only be seen on Guadalupe Island. I do not know of any travel restrictions, but you will probably have to have or hire a boat to get there. Information on its distribution and habitat on the island are provided by Instituto Nacional de Ecología (2002).

Remarks

This species is also listed as endangered by the Mexican government (NOM-ECOL-059-94).

Collected by Dr. E. Palmer (Watson 1879).

Citations

Bartel 2009 is in Adams, R.P., J.A. Bartel and R.A. Price. 2009. A new genus, Hesperocyparis, for the cypresses of the western hemisphere. Phytologia 91(1):160-185.

Bonner, F.T. (tech. ed.). [no date]. Woody plant seed manual. U.S.D.A.; http://wpsm.net/Introduction.htm, accessed 2003.05.04, now defunct.

California Registry of Big Trees. 2003. http://www.ufei.org/bigtrees/bigtreelist.lasso, accessed 2003.05.04, now defunct.

IUCN 2002. 2002 IUCN Red List of Threatened Species. http://www.redlist.org/search/details.php?species=34080, accessed 2007.01.01.

Nearctica. 2000. Nearctica - Native Conifers of North America - Cupressus guadalupensis. http://www.nearctica.com/trees/conifer/cupress/Cguada.htm, accessed 2007.01.01, now defunct.

Watson, Sereno. 1879. Contributions to American botany. II. Descriptions of some new species of North American plants. Proceedings of the American Academy of Arts and Sciences 14:288-303 (p. 300).

See also

The species account at Threatened Conifers of the World.

Aguirre-Muñoz, A., A. Samaniego-Herrera, L. Luna-Mendoza, A. Ortiz-Alcaraz, M. Rodríguez-Malagón, M. Félix-Lizárraga, F. Méndez-Sánchez, R. González-Gómez, F. Torres-García, J.C. Hernández-Montoya, J.M. Barredo-Barberena, and M. Latofski-Robles. 2011. Eradications of invasive mammals on islands in México: the roles of history and the collaboration between government agencies, local communities and a non-government organization. Island Invasives: Eradication and Management. Proceedings of the International Conference on Island Invasives. Gland, Switzerland: IUCN and Auckland, New Zealand: CBB. xii + 542pp. Available: issg.org.

Oberbauer, Thomas A., Luciana Luna Mendoza, Nadia Citlali Olivares, Lucía Barbosa Deveze, Isabel Granillo Duarte, and Scott A. Morrison. 2009. Fire on Guadalupe Island reveals some old wounds, and new opportunity. Fremontia 37(3):2-11. Available cnps.org/wp-content/uploads/2018/03/Fremontia_Vol37-No3.pdf, accessed 2023.12.17.

Farjon (2005) and Wolf (1948) provide detailed accounts, with illustrations.

Moran, R. 1996. The flora of Guadalupe Island, Mexico. San Francisco: California Academy of Sciences.