Juniperus standleyi

Steyerm. ex Standl. & Steyer. 1943

Common names

Huitó, huitum, cipres (Farjon 2005).

Taxonomic notes

No synonyms. Type: Guatemala, San Marcos, Volcan de Tacana, J.A. Steyermark 36137 (holotype F!). Earlier analyses agreed in assigning it a close association with J. durangensis and J. monticola on morphological and chemosystematic grounds (Martinez 1963, Zanoni and Adams 1976). The most recent genetic analyses place it within an entirely Central American clade of Section Sabina, closest to J. monticola (another subalpine species) but also sister to J. flaccida, J. jaliscana, and J. poblana; divergence from J. monticola is estimated to have occurred about 7 million years ago (Uckele et al. 2021).

Description

Dioecious evergreen shrubs and trees to 15 m tall, often with a contorted main stem, and an irregular crown of spreading and ascending branches. Bark comprised of longitudinal strips. Twigs reddish-brown, ultimate twigs branching at 40-50°. Whip leaves decurrent, otherwise scale-like; scale leaves yellow-green to dark green, opposite to ternate, ovate to broad-ovate, 1.5-2.0 mm long, bearing a basal resin gland; margins finely toothed, tips appressed, rounded or obtuse. Pollen cones fertile November to January. Seed cones on short, curved peduncles, ovoid to irregular, 7-9 mm diameter, when ripe glaucous dark blue with soft fleshy pulp, bearing 3-5 seeds that are 4-5 × 2.5-3.7 mm, subconic, grooved, dark brown (Adams 2014).

Distribution and Ecology

Guatemala highlands; Mexico: Chiapas, Volcan Tacana. Occurs at elevations of 3000-4250 m in open Pinus woodland, or sometimes in pure stands, often on rocky edges and talus slopes of mesas, or on limestone ridges. Typical associates include a variety of shrubs, grasses, and forbs, and it is sometimes on land under Agave cultivation. At its upper elevation limit it occurs with Pinus hartwegii, and it can be found above timberline on the Chiapas side of Volcan Tacana (Adams 2014, Farjon 2013).

The IUCN assesses this species as "Endangered" due to a limited distribution and a steep population decline since it was first described. Official permission is needed to cut the trees (shrubs are not used) but the local inhabitants largely ignore this rule. In the rainy season there is extensive sheep grazing on the altiplano, which prevents successful regeneration. The most recent assessment determined that "This species is in urgent need of protection. Rules and regulations that cannot be enforced are not helpful" (Farjon 2013).

Hardy to Zone 8 (cold hardiness limit between -12.1°C and -6.7°C) (Bannister and Neuner 2001).

Remarkable Specimens

No data as of 2023.03.03.

Ethnobotany

The local Todosanteros Indians use the wood for fence posts and shingles, and smaller wood may serve as firewood (Farjon 2013).

Observations

Remarks

The epithet honors American botanist Paul C. Standley (1884-1963), Steyermark's co-author in the publication of this species.

Citations

Adams, Robert P. 2000. The serrate leaf margined Juniperus (Section Sabina) of the western hemisphere: systematics and evolution based on leaf essential oils and Random Amplified Polymorphic DNAs (RAPDs). Biochemical Systematics and Ecology 28: 975-989.

Adams, Robert P. 2014. Junipers of the World: The Genus Juniperus. Fourth edition. Trafford Publishing. Brief versions of the descriptions are available online at Adam's website, www.juniperus.org.

Farhat, P., O. Hidalgo, T. Robert, S. Siljak-Yakovlev, I. J. Leitch, R. P. Adams, and M. Bou Dagher-Kharrat. 2019. Polyploidy in the Conifer Genus Juniperus: An Unexpectedly High Rate. Frontiers in Plant Science 10, doi: 10.3389/fpls.2019.00676.

Farjon, A. 2013. Juniperus standleyi. The IUCN Red List of Threatened Species 2013: e.T32501A2820961. https://dx.doi.org/10.2305/IUCN.UK.2013-1.RLTS.T32501A2820961.en, accessed 2022.12.27.

Martinez, M. 1963. La pinaceas mexicanas. Tercera edicion. Mexico City: Universidad Nacional Autonoma de Mexico.

Standley, P. C. and J. A. Steyermark. 1943. Studies of Central American Plants III. Publ. Field Mus. Nat. Hist. Bot. Ser. 23(1):3. Available: Biodiversity Heritage Library, accessed 2022.12.27.

Uckele, Kathryn A., Robert P. Adams, Andrea E. Schwarzbach, and Thomas L. Parchman. 2021. Genome-wide RAD sequencing resolves the evolutionary history of serrate leaf Juniperus and reveals discordance with chloroplast phylogeny." Molecular Phylogenetics and Evolution 156:107022.

Zanoni, T.A. and R.P. Adams. 1976. The genus Juniperus (Cupressaceae) in Mexico and Guatemala: numerical and chemosystematic analysis. Biochemical Systematics and Ecology 4: 147-158.

See also

The species account at Threatened Conifers of the World.

Adams, R. P., Zanoni, T. A., and Hogge, L. 1985. The volatile leaf oils of Juniperus comitana, J. gamboana, and J. standleyi. J. Nat. Prod. 48:678-681.

Adams, R. P., M. Socorro González-Elizondo, Martha González-Elizondo, and Andrea E. Schwarzbach. 2018. The Juniperus flaccida-J. poblana complex revisited: insights from molecular and oil analysis. Phytologia 100(1):19-26.

Farjon (2005) provides a detailed account, with illustrations.

Islebe, G. A., and Ai Velázquez. 1994. Affinity among mountain ranges in Megamexico: A phytogeographical scenario. Vegetatio 115(1):1-9.

Islebe, G. A., A. Velázquez, and A. M. Cleef. 1995. High elevation coniferous vegetation of Guatemala. Vegetatio 116(1):7-23.