Picea retroflexa

Masters 1906

Common names

Green dragon spruce, 鳞皮云杉 [Chinese].

Taxonomic notes

Syn: P. gemmata Rehder et Wilson 1914; P. asperata var. retroflexa (Masters) Cheng 1937; P. aurantiaca var. retroflexa (Masters) C.T. Kuan et L.J. Zhou 1983 (Farjon 1998). Type locality near Kangding, Sichuan (Masters 1906).

The analysis by Ran et al. (2006), using both molecular markers and character states, placed P. retroflexa in a clade with P. abies and a number of other quadrangular-leaved Asian spruces including P. asperata, P. crassifolia, P. koraiensis, P. koyamae, P. meyeri, and P. obovata.

Description

Trees to 45 m tall and 150 cm dbh with a single straight, round trunk and a conical to columnar crown of numerous short, straight, horizontal primary branches. Bark rough and scaly, comprised of small, flaky plates. Twigs short, thick, light- or orange-brown, strongly ridged and grooved with conspicuous pulvini 1-2 × 1-1.5 mm. Foliage buds broad-conical, resinous, 5-10 × 5-10 mm, closely surrounded by curved leaves, with keeled, appressed, orange-brown bud scales that persist for several years at the base of the shoot. Leaves light- to glaucous-green, radially spreading, curved forward, 12-18 × 1.5-2 mm, linear, quadrangular with prominent ribs, apex sharply pointed, with stomata in paired bands of 2-3 lines on upper surfaces and 4-6 lines on lower surfaces. Pollen cones axillary, 3-5 cm long, ripening reddish yellow. Seed cones terminal, erect becoming pendulous, sessile, oval-oblong to cylindric-conical/obtuse, 8-13 × 2-4 cm when fully open; purple-red when immature, maturing purple-brown. Seed scales obovate, 15-20 × 12-15 mm at mid-cone, lower surface striated and shiny, outer margin slightly erose or denticulate, straight to reflexed when open. Bracts 5-6 mm long, included. Seeds ovoid-oblong, 3-4 mm long, dark brown, with a 10-15 × 5-7 mm pale brown obovate wing (Farjon 2010).

Distribution and Ecology

China: W Sichuan, SE Xizang (Farjon and Page 1999). Occurs in the subalpine zone at 3000-4000(-4700) m elevation, mostly on northern aspects with acid soils. Climate continental, relatively dry. Common associates at lower elevations include P. likiangensis var. rubescens, P. aurantiaca, Abies chensiensis, Tsuga chinensis, and Betula albo-sinensis; at higher elevations it commonly grows with Abies squamata (Farjon 2010). Due to its limited range and ongoing exploitation of the lower subalpine forest in this range, it has been classified by the IUCN as "vulnerable", but there are data quality problems owing to the history of debate (which is ongoing) regarding the systematics of Picea in western Sichuan; briefly, many published accounts of the forests of this region are unreliable regarding identification of Picea (or Abies for that matter) species, and thus the species' precise distribution must be inferred from a rather limited collection of herbarium specimens.

Remarkable Specimens

Ethnobotany

Observations

Remarks

Masters (1906) states that pulvini on the shoots are bent back along the shoot axis (patenti-reflexi); this may be the origin of the epithet retroflexa. His description also states "very remarkable in its sharply decurved cone-scales", so the epithet may also allude to that character.

Citations

M. T. Masters. 1906. On the conifers of China. Journal of the Linnaean Society, Botany 37(262):410-424. Available: biodiversitylibrary.org/page/230356, accessed 2014.11.28.

See also

The species account at Threatened Conifers of the World.