Cycas taitungensis Image
Cycas taitungensis
Copyright © Phil Markey

Cycas taitungensis

Family: Cycadae    Cycad

Common Name: Emperor Sago

Scientific Synonymy:
Cycas taiwaniana

Common Synonymy:
Prince sago

Cold Hardiness Zone: 9b     View the UK and US zone maps

Identification:
Stems arborescent, to 6 m tall, 25-30 cm diam. Leaves deep green, glabrous, 100-180 cm long, slightly keeled (opposing leaflets inserted at 120-170 on rachis), with 150-170 leaflets, with orange tomentum shedding as leaf expands; rachis usually terminated by a spine. Petiole 15-20 cm long (15-20% of total leaf), petiole glabrous, spinescent for 50-90% of length. Basal leaflets gradually reducing to spines, 30 mm long. Median leaflets simple, strongly discolourous, 120-170 mm long, 6-8 mm wide, inserted at 45-60 to rachis, decurrent for 2.5-4.5 mm, narrowed to 2-2.5 mm at base (to 30-45% of maximum width), 4.5-6 mm apart on rachis; median leaflets section slightly keeled; margins recurved; apex acute, spinescent; midrib flat above, raised below. Cataphylls linear, pungent, densely floccose, persistent. Pollen cones fusiform, yellow, 35-50 cm long, 8.5-10 cm diam.; microsporophyll lamina waxy, not dorsiventrally thickened, 35-40 mm long, 11.5-15 mm wide, fertile zone 25-30 mm long, sterile apex 4.5-10 mm long, apical spine absent, apex deflexed, 6 mm long. Megasporophylls 21-26 cm long, brown-tomentose; ovules 2-6, pubescent; lamina orbicular, 100-130 mm long, 80-100 mm wide, deeply pectinate, with 28-36 soft lateral spines 35-45 mm long, 1.5-3 mm wide, apical spine not distinct from lateral spines. Seeds oblong, 40-45 mm long, 25-30 mm wide; sarcotesta red, slightly pruinose, 1.5-3 mm thick; fibrous layer absent; sclerotesta longitudinally grooved. Spongy endocarp absent.

General Information:
Although not described until 1994, this species was widely known previously under the misapplied name C. taiwaniana. Very closely related to C. revoluta, this species is readily distinguished by the longer, flatter leaves with longer, broader and flatter leaflets. Female cones also tend to be more tightly imbricate and cabbage-like, and seeds are darker in colour. Cycas taitungensis is now under serious threat from the invasive Cycad Aulacaspis Scale, which first reached the wild populations in 2004.

Distribution:

Native to, Taiwan

Known only from 2 locations on steep, south facing slopes between 300 m alt., and 950 m alt.

Location: Taiwan (22.866816°N, 120.999214°E)

Observations
Map may not represent the complete natural distribution. (Markers display observation data).


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