Photo Ken Hill
The Cycad Pages
Cycas balansae

Cycas balansae Warb., Monsunia 1: 179 (1900).
"TYPE: Vietnam, ""Tonkin"", Hanoi, Mar 1889, B. Balansa 4084 (lecto G; isolecto G, K, LE, P)."

Etymology: Honouring French naturalist and botanical explorer Benedict Balansa (1825-1892), who collected extensively for the Museum of Natural History in Paris, and spent the years 1885 to 1892 collecting in Tonkin (North Vietnam), where he died.

Illustrations: Wang 1996 (as C. shiwandashanica)

Historical notes: Described by German botanist Otto Warburg in 1900. A single collection was cited as `Im Herbarium Barbey finde ich von Balansa sub Nr. 4084 gesammelte ♂ Zapfen aus Tongking, nahe Hanoi aus einem Tempelhof stammend ...'. The Barbey-Boissier herbarium and types are in G. Balansa collections are also in P. Warburg types were mostly held by B, and Schuster (1932) cited a specimen probably from B which would probably have been the type: `Tongking: Village du papier bei Hanoi, im Hof einer Pagode (B. Balansa IV. 1889, n. 4084).' This specimen was destroyed in WW2. The specimens in G were not annotated by Warburg or Schuster, and may not have been seen by either. Three sheets exist, two in the Barbey-Boissier herbarium and one in the DC herbarium. All are of male cones and sporophylls only, and the specimen in the De Candolle herbarium is here designated the lectotype This specimen is annotated `B. Balansa - Pl. du Tonkin - 1885-1889/Nr. 4084/Dioique. Frone de deux metres de hauteur/Tongking: Village du papier près de Hanoi, dans la/cour d'une pagode/Avril 1889' [Dioecious. Fronds 2 m high. Paper village near Hanoi, in the garden of a pagoda].

Distinguishing features: This species is one of the complex of closely related mostly acaulescent taxa that is distributed through northern Vietnam, Laos, northern Thailand and Yunnan and Guangxi in southern China (Section Stangerioides). It is distinguished by the few long leaves with long petioles bearing long slender spines and a deep purple-brown tomentum that is often persistent. Male cones are intermediate in size, as are megasporophylls, these with a few, long and slender divisions on the lamina. Seeds are small.

Distribution and habitat: Locally frequent although not in dense stands, in more sheltered sites in deep shade in tall closed evergreen forests, mainly in the mountainous region north-east of Hanoi, and in south-eastern Guangxi province of China (the Shi Wan Da Shan). On loamy soils over schists or granites.

Conservation status: Although some populations have been depleted in recent decades, large populations remain essentially undisturbed in mountainous areas, some of which are in conservation areas. Not considered to be at risk, IUCN (1994) status LR, nt.
Photo Ken Hill
Photo Ken Hill


Stems acaulescent, 12-20 cm diam. at narrowest point; 4-9 leaves in crown.

Leaves deep green, highly glossy to semiglossy, 120-260 cm long, slightly keeled to flat (not keeled) in section (opposing leaflets inserted at 160-180° on rachis), with 90-160 leaflets, with brown tomentum shedding as leaf expands or persistent above and below; rachis consistently terminated by paired leaflets. Petiole 40-160 cm long (30-40% of total leaf), petiole pubescent, spinescent for 90-100% of length. Basal leaflets not gradually reducing to spines, 90-210 mm long.

Median leaflets simple, strongly discolorous, 220-300 mm long, 10-15 mm wide, inserted at 75-85° to rachis, decurrent for 5-8 mm, narrowed to 3-4 mm at base (to 25-35% of maximum width), 11-21 mm apart on rachis; median leaflets section flat; margins flat, or slightly recurved; apex softly acuminate, not spinescent; midrib raised above, flat below.

Cataphylls narrowly triangular, soft, pilose, 60-70 mm long, articulated.

Pollen cones fusiform, yellow, 20-25 cm long, 4-7 cm diam.; microsporophyll lamina soft, not dorsiventrally thickened, 16-30 mm long, 11-14 mm wide, fertile zone 14-28 mm long, sterile apex 2-4 mm long, level, apical spine absent.

Megasporophylls 8-12 cm long, brown-tomentose; ovules 2-4, glabrous; lamina ovate, 40-60 mm long, 30-55 mm wide, deeply pectinate, with 14-24 soft lateral spines 25-40 mm long, 2-3 mm wide, apical spine not distinct from lateral spines.

Seeds ovoid, 25-27 mm long, 20 mm wide; sarcotesta yellow, not pruinose, 2 mm thick; fibrous layer absent; sclerotesta verrucose. Spongy endocarp absent.

The Cycad Pages

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Written and maintained by Ken Hill 1998-2010
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