The Cycad Pages
Cycas ferruginea

Cycas ferruginea F.N. Wei, Guihaia 14: 300 (1994).
"TYPE: cultivated, Guilin Botanical Garden, introduced from Longzhou County, Guanxi, China, F.N. Wei 2220, 31 Aug. 1994 (holo IBK)."

Etymology: Latin ferruginea rusty red, from the abundant deep red tomentum on new growth and persisting to some extent on the older leaves.

Historical notes: Described by Chinese botanist Wei Fan-Nan in 1995, from a single plant in cultivation in Guilin. The wild source was not known at the time, making the origin something of a mystery. Field studies in Vietnam in 1997 discovered large populations of a cycad that appears to match the type plant in Lang Son province. More recently, additional wild populations have been discovered in south-western Guangxi Province in China

Distinguishing features: Closely allied to C. sexseminifera, but immediately distinguished by the dense dark ferruginous tomentum on new growth, the longer leaves and the longer often falcate leaflets with recurved margins. It also differs in the generally larger proportions in all respects, and the larger and broader megasporophyll lamina with a distinct, broad apical spine.

Distribution and habitat: A restricted species, known from a belt of limestone bluffs in Lang Son province. This species shows the same habitat preference as C. sexseminifera and C. tropophylla, growing on bare limestone faces on steep limestone bluffs, with no visible soil at the roots.

Conservation status: Not considered to be at risk. IUCN (1994) Red List status LR nt.
Photo Ken Hill


Stems arborescent or acaulescent, to 1.2 m tall, 12-18 cm diam. at narrowest point; 10-25 leaves in crown.

Leaves deep green or grey-green, highly glossy or semiglossy, 130-210 cm long, slightly keeled or flat (not keeled) in section (opposing leaflets inserted at 150-180° on rachis), with 120-200 leaflets, with white, orange or brown tomentum shedding as leaf expands or persistent below; rachis usually terminated by paired leaflets. Petiole 35-80 cm long (25-40% of total leaf), petiole glabrous or pubescent, spinescent for 30-100% of length. Basal leaflets not gradually reducing to spines, 80-190 mm long.

Median leaflets simple (often falcate), strongly discolorous, 190-380 mm long, 8-13 mm wide, inserted at 70-90° to rachis, decurrent for 4-8 mm, narrowed to 2.5-4 mm at base (to 25-40% of maximum width), 10-19 mm apart on rachis; median leaflets section slightly keeled; margins recurved; apex acute, spinescent; midrib raised above, flat below.

Cataphylls narrowly triangular, pungent, pilose, 90-120 mm long, persistent.

Pollen cones fusiform, orange, 25-45 cm long, 4-6 cm diam.; microsporophyll lamina soft, not dorsiventrally thickened, 16-20 mm long, 9-13 mm wide, fertile zone 15-18 mm long, sterile apex 3-5 mm long, raised, apical spine rudimentary or absent, sharply upturned, 0-3 mm long.

Megasporophylls 11-19 cm long, brown-tomentose; ovules 2-6, glabrous; lamina orbicular, 70-110 mm long, 50-80 mm wide, deeply pectinate, with 28-42 soft lateral spines 18-40 mm long, 1-3 mm wide, apical spine distinct from lateral spines, 15-50 mm long, 3-8 mm wide at base.

Seeds ovoid, 19-24 mm long, 15-21 mm wide; sarcotesta yellow, not pruinose, 1-2 mm thick; fibrous layer absent; sclerotesta verrucose. Spongy endocarp absent.

The Cycad Pages

© 1998-2012 Royal Botanic Gardens Sydney
Written and maintained by Ken Hill 1998-2010
Maintained by Leonie Stanberg and Dennis Stevenson 2010-2012
This site is currently not being maintained