Picea alcoquiana belongs to Clade III of Ran et al. (2006), indicating that it is sister to a clade containing P. abies and most of the other northeast Asian spruces. It is the most anomalous species in the northeast Asian group, sister to a clade containing P. mariana, P. rubens, and P. omorika (note, however, that genetic material for this species was sampled from a single tree in a Swiss botanic garden).
Synonymy for the type variety (Farjon 1998):
Synonymy for variety acicularis (Farjon 1998):
Synonymy for variety reflexa: Picea bicolor (Maxim.) Mayr var. reflexa Shirasawa 1913 (Farjon 1998).
Monoecious. Evergreen tree to 30 m tall and 100 cm dbh, with a straight round trunk and long, slender, spreading branches. Bark purple-brown, soon scaly on young trees, maturing to gray-brown, fissured and peeling off in thick scales. Branchlets slender, red-brown, smooth, ridged and grooved, glabrous, with small pulvini 0.5-0.6 mm long diverging at 50-80° from shoot axis. Leaf buds 3-5 mm long, resinous, with triangular, brown, persistent scales. Leaves coriaceous, linear, quadrangular, 10-15 mm long, 1.5 mm across, acutely pointed on young trees, slightly pointed on mature trees, deep green, with 1-3 stomatal lines on ventral, and 3-6 on dorsal surfaces; resin canals two, marginal. Flowers May to June, solitary, terminal on previous year's shoots. Pollen cones 10-15 mm long, red turning yellow, with numerous stamens. Seed cones cones pendant, very short pedunculate, ovoid, red-purple before maturity, ripening in October to red-brown or pale brown, oblong or cylindric, (5-)7-9(-12) cm long, (2.5-)3(-5.5) cm across when open, scales loosely overlapping before maturity. Scales thinly woody, orbicular-ovate, narrowing upward, cuneate to base, 13-16 mm long and wide, denticulate on margin. Bracts very small, obovate, acute, slightly laciniate on margin, 3-4 mm long, 2 mm wide. Seeds oblong-obovate, blackish brown, ca. 4 mm long, 2 mm wide; wings brown, obovate or oblong-obovate, 7-10 mm long, 4-5 mm wide (Farjon 1990, Iwatsuki et al. 1995).
Variety acicularis is distinguished by having strongly curved, 1.3-2.5 cm long leaves and 6-15 cm long cones with a narrowed apex. It is in some ways intermediate between the type variety and Picea koyamae, with which it grows (Farjon 1990).
Variety reflexa is distinguished by having shorter leaves and smaller (4-7.5 cm long) cones with entire, apically narrowed and reflexed seed scales (Farjon 1990).
Japan: on the Pacific Ocean side of C Honshu, at 1500-2000 m elevation in subalpine forests (Iwatsuki et al. 1995). The climate is cool, with snowy winters and 1000-2500 m annual precipitation. Soils are volcanic. Typically grows in mixed conifer forests with Picea jezoensis ssp. hondoensis, Tsuga diversifolia, Larix kaempferi. In some areas it is found with Pinus parviflora and Abies veitchii, and it grows at high elevations with Abies mariesii. Common angiosperm trees in these forests include Betula ermanii, Betula grossa, Sorbus commixta, Quercus mongolica var. grosseserrata, Alnus hirsuta var. siberica and Prunus maximowiczii (Farjon 1990). Hardy to Zone 5 (cold hardiness limit between -28.8°C and -23.3°C) (Bannister and Neuner 2001).
The distribution of the type variety is mainly in the Kanto Mountains and the Chubu Mountains; of var. acicularis, in the Yatsugadake Mountains; and of var. reflexa, in the Akaishi Range (Farjon 1990).
Var. acicularis provides a useful timber (World Conservation Monitoring Centre - Trees).
Picea alcoquiana var. reflexa is on the WCMC Red List: vulnerable, population stable, known from fewer than five localities. "A few (<5) small populations in scattered locations are confined to the volcanic Akaishi range of central Honshu. They occur in mixed montane forest" (World Conservation Monitoring Centre - Trees).
Picea alcoquiana var. acicularis is also on the WCMC Red List: vulnerable, population stable, known from fewer than five localities. "Endemic to the Yatsugadake Mts. this variety is restricted to a small area (<100km2) of montane forest, most of it being state forest" (World Conservation Monitoring Centre - Trees).
Beissner, L. and J. Fitschen. 1930. Handbuch der Nadelholzkunde. 3. Aufl. Berlin.
Farjon, Aljos. 1990. Pinaceae: drawings and descriptions of the genera Abies, Cedrus, Pseudolarix, Keteleeria, Nothotsuga, Tsuga, Cathaya, Pseudotsuga, Larix and Picea. Königstein: Koeltz Scientific Books.
The species account at Threatened Conifers of the World.
Farjon (1990) provides good pen-and-ink drawings of horticultural specimens of each variety.
Last Modified 2017-12-29