The Gymnosperm Database

photo

Sapling on the path to Pico Turquino, elevation ca. 1400-1500 m, just before Pico Cuba [Réjean Drouin, 2010].

map

Approximate distribution of J. saxicola.

 

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Conservation status

Juniperus saxicola

Britton et P. Wilson 1923

Common names

Taxonomic notes

Synonymy:

Type specimen León 10798 (NY) from Sierra Maestra, Oriente, Granma Province (Adams 1995).

This is one of about 40 species in Juniperus section Sabina, and one of four closely related species of Caribbean junipers (the others are J. barbadensis, J. bermudiana, and J. gracilior). Both terpene data and nuclear ribosomal DNA data tie J. saxicola most closely to J. barbadensis var. barbadensis and J. barbadensis var. lucayana, the former species found in St. Lucia, the latter in Bahamas and western Cuba (Adams 2008). The relationship is close enough that this taxon could reasonably be treated at the subspecies rank, but is not as close as the relationship between the varieties of J. barbadensis. Also, since J. saxicola does not develop scale-leaved foliage, it is very different in appearance from the other Caribbean junipers.

Description

Tree or shrub 3-8 m tall. Leaves always needle-like, decurrent, spreading, 5-7 mm long and ca. 1 mm wide, scale leaves never present on adult trees (see Remarks). Seed cones dark blue with bloom, subglobose to reniform, 5 mm long, 3-4 mm diameter, 2 seeds per cone (Adams 1995).

Distribution and Ecology

Cuba: Granma Province: on the rocky crests of the Sierra Maestra and Pico Turquino (Adams 1995). Farjon (2005) calls this habitat a xeromorphic variant of cloud forest, and says that the juniper prevails where rocky terrain precludes dominance of co-occurring species such as Cleyera ekmannii, Clusia tetrastigma, Haenianthus salicifolius, Lyonnia turquini, and Ternstroemia microcalyx.

Big tree

Oldest

Dendrochronology

No use has been recorded.

Ethnobotany

No use has been recorded.

Observations

Representative specimens have been collected at the Cueva del Aura on Sierra Maestra, and on Pico Turquino (20° N, 17°50' W) at 1600-1700 m elevation on the steep rocks of Loma Regiona (the Pico's north spur) and on the summit of the Pico (Adams 1995). Pico Turquino is the highest point in Cuba, and the area has been preserved in Parque Nacional Turquino.

Remarks

In Juniperus section Sabina, only young (up to 4 or 5 years) junipers have solely juvenile (needle- or awn-shaped, decurrent) leaves. Scale-like leaves are then produced as the only adult foliage, except that juvenile foliage may occasionally appear at branch tips or in response to damage. Five species constitute exceptions to this rule: J. coxii, J. recurva, J. morrisonicola and J. squamata in the eastern hemisphere, and J. saxicola in the western. These species are neotenic: they have apparently reverted to the primitive condition of having only one type of foliage, which is the juvenile form (Adams 2008).

Adams (2008) proposes that the four Caribbean juniper species arose from long distance bird dispersal of Juniperus virginiana seeds from North America, first to the Bahamas, and then to Bermuda, Cuba, Jamaica, and Hispaniola. J. saxicola likely evolved from Cuban populations of J. barbadensis var. lucayana, with the neotenic state likely originating from founder's effect or genetic drift, both of which would have been associated with a very small population size, consistent with the modern very limited distribution of this species. Based on our knowledge of sea level and geologic change in the Caribbean, all of this likely happened during Pleistocene time (the past 1.8 million years).

Citations

Adams, Robert P. 1995. Revisionary study of Caribbean species of Juniperus (Cupressaceae). Phytologia 78: 134-150.

Adams, Robert P. 2008. Junipers of the World: The Genus Juniperus. Second edition. Trafford Publishing. Brief versions of the descriptions are available online at Adam's website, www.juniperus.org.

Britton, N. L. and P. Wilson. 1923. Bulletin of the Torrey Botanical Club 50:35.

See also

The species account at Threatened Conifers of the World.

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

Last Modified 2017-12-29