Juniperus komarovii

Florin 1927

Common names

枝圆柏 ta zhi yuan bai [Chinese] (Fu et al. 1999).

Taxonomic notes

This is one of the central Asian turbinate-cone junipers, a taxonomically complex group subdivided mainly on the basis of molecular studies that have almost all been performed by R. P. Adams and coworkers; the principal such studies were by Adams and Schwarzbach (2012, 2013); see the cladogram of Juniperus for a summary of relationships in the group. J. komarovii is sister to J. convallium in independent molecular analyses by both Adams and Schwarzbach (2013) and Leslie et al. (2012).

Syn.: Juniperus glaucescens Florin; Sabina komarovii (Florin) W. C. Cheng et W. T. Wang (Fu et al. 1999).

Description

Monoecious trees up to 20 m tall with a straight, usually single trunk and open, irregular crown, with drooping or pendulous branches. Bark brownish gray or, more often, bleached to gray. Branchlet systems tapering and gradually becoming shorter from base to apex of system; branchlets loosely arranged, ascending, straight or slightly curved, terete or 4-angled, thick, ultimate ones 1.2-1.5 mm in diameter. Leaves decussate, occasionally in whorls of 3 on leading branches, scale-like, ovate-triangular or triangular-lanceolate, 1.5-3.5(-6) mm, without cuticular wax, with an abaxial gland near base, ovate or elliptic, leaf apex acute, slightly incurved but free. Pollen cones ovoid or globose, 2-3 mm; microsporophylls usually 10, each with 2 or 3 pollen sacs. Seed cones erect, purple-black or black when ripe, slightly glaucous, ovoid or subglobose, 8-10(-12) mm, 1-seeded. Seeds ovoid, rarely obovoid, 6-8.5 mm, obtusely ridged, narrowed by resin pits toward base (Fu et al. 1999), field observations 1988.04.

Distribution and Ecology

China: S Qinghai and NW Sichuan (Fu et al. 1999) and Russia (local in S Ussuriland) (Vladimir Dinets e-mail, 1998.01.12). Typically in forests at 3,000-4,000 m elevation (Fu et al. 1999). Hardy to Zone 6 (cold hardiness limit between -23.2°C and -17.8°C) (Bannister and Neuner 2001).

I have seen it in forests on the W side of Gongga Shan in the Daxue Shan of Sichuan, where it grows on dry steep S slopes forming a woodland of erect trees 10-20 m tall; the corresponding N slopes support forests of Picea likiangensis, or on slightly drier sites, Quercus aquifolioides. The understory contains a variety of shrubs well adapted to cold dry climate and grazing by goats, notably Juniperus squamata var. wilsonii.

Remarkable Specimens

I collected a tree-ring chronology (unpublished) in 1989 from Liu Ba (China: Sichuan). One sample, LIU-9A, had a 1559-1989 ring count, giving a minimum age of 430 yrs. Many other sampled trees approached this age. Circuit uniformity in this species is good and many trees were over 300 years old, but I found very low correlation between trees due to intensive human disturbance, chiefly the cutting of juniper boughs to be burned as incense at nearby Buddhist monasteries. Populations not exploited by cutting or pruning might be dendroclimatically useful.

Ethnobotany

No data as of 2023.03.03.

Observations

No data as of 2023.03.03.

Remarks

The epithet honors Russian botanist Vladimir Leontyevich Komarov (1869-1945), who explored extensively in the Russian Far East and described many conifer taxa.

Citations

Adams, R. P., and A. E. Schwarzbach. 2012. Taxonomy of the turbinate shaped seed cone taxa of Juniperus, section Sabina: sequence analysis of nrDNA and four cpDNA regions. Phytologia 94(3):388-403.

Adams, R. P., and A. E. Schwarzbach. 2013. Taxonomy of the turbinate shaped seed cone taxa of Juniperus, section Sabina: Revisited. Phytologia 95:122–124.

Leslie, A. B., J. M. Beaulieu, H. S. Rai, P. R. Crane, M. J. Donoghue, and S. Mathews. 2012. Hemisphere-scale differences in conifer evolutionary dynamics. Proceedings of the National Academy of Sciences 109(40):16217–16221. Note that the cladistic analysis of Juniperus appears only in the Supplement.

See also

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