The Cycad Pages
Cycas canalis

Cycas canalis K.D. Hill, "Telopea 5(4): 698-700, fig. 4a -4d" (1994). H—NSW
"TYPE: Australia, Northern Territory, 31.4 km from Labelle Downs homestead on track to Channel Point, K.D. Hill 4034 & L. Stanberg, 8 Sep 1991 (holo NSW; iso CANB, DNA)."[NSW]

Etymology: From the Latin canalis, a canal or channel, in reference to the occurrence of this species at Channel Point

Distinguishing features: distinguished by the strongly glaucous new growth, the long leaflets with flat margins and midrib more prominent below, and the thickly woolly and prominent cataphylls.

Distribution: widespread and locally abundant, on a variety of well-drained soil types, usually on lateritic soil profiles in open forest or woodland with Eucalyptus miniata. Known from near-coastal sites at Channel Point, apparently disjunct from inland occurrences extending from west of Dorisvale to around Douglas Daly reserve. The inland populations differ in the longer leaves, petioles and leaflets, and the keeled leaves, and the lower rachis-to-leaflet angle, and have been recognised as a distinct subspecies.

Key to the subspecies.

1 leaflet-to-rachis angle 60° or more, leaves flat -- A. subsp. canalis

1* leaflet-to-rachis angle less than 60°, leaves openly keeled -- B. subsp. carinata

A. Cycas canalis subsp. canalis

Illustration: Hill 1994, fig. 4a-d.

Distinguished from the other subspecies by the non-keeled leaves and the high leaflet-to-rachis angle (60--90°). Leaves also tend to be somewhat smaller (60--90 cm long) with smaller leaflets (100--190 X 4.5--7.5 mm).

Locally abundant in near-coastal situations, on well-drained soil in Eucalyptus miniata forest. Known from around Channel Point, to the north of the mouth of the Daly River, and reported from coastal country south of the mouth of the Daly River (no confirmatory specimens are known).

Conservation status: locally extremely abundant, not considered to be at risk. Although not well reserved, the extreme abundance of this species would buffer it from any threat in the medium term. However, frequent fire effectively blocks reproduction, and uncontrolled development could potentially destroy large proportions of the population.

B. Cycas canalis subsp. carinata

Illustration: Hill 1994, fig. 4e-g.

Distinguished from subsp. canalis by the keeled leaves and the low leaflet-to-rachis angle (40--50°). Leaves also tend to be longer (70--105 cm long), with larger leaflets (125--205 X 4.5--8 mm).

A sporadic and scattered taxon, usually on lateritic soil profiles in open forest or woodland with Eucalyptus miniata. Known from west of Dorisvale to around Douglas Daly Reserve.

Conservation status: Widespread, not considered to be at risk.


Stems arborescent, to 3(-5) m tall, 7-14 cm diam. at narrowest point.

Leaves blue (aging to bright green), semiglossy, 60-105 cm long, slightly keeled to flat (not keeled) in section (opposing leaflets inserted at 130-180° on rachis), with 100-170 leaflets, with white and orange tomentum shedding as leaf expands; rachis usually terminated by a spine. Petiole 15-25 cm long, glabrous (or loosely orange-tomentose), spinescent for 70-100% of length. Basal leaflets not gradually reducing to spines.

Median leaflets simple, weakly discolorous, 100-205 mm long, 4.5-8 mm wide, inserted at 40-90° to rachis, decurrent for 1-2 mm, narrowed to 3-5 mm at base (to 40-60% of maximum width), 6-12 mm apart on rachis; median leaflets section flat; margins flat; apex aristate, not spinescent; midrib raised above (slightly), raised below.

Cataphylls linear, pungent, densely floccose, 70-90 mm long, persistent.

Pollen cones ovoid, orange, 15-22 cm long, 8-12 cm diam.; microsporophyll lamina firm, not dorsiventrally thickened, 35-45 mm long, 15-23 mm wide, fertile zone 28-32 mm long, sterile apex 8-14 mm long, level, apical spine prominent, sharply upturned, 11-18 mm long.

Megasporophylls 16-25 cm long, grey-tomentose and brown-tomentose; ovules 2-4, glabrous; lamina lanceolate, 40-60 mm long, 22-32 mm wide, regularly dentate, with 12-20 pungent lateral spines 2-6 mm long, 2 mm wide, apical spine distinct from lateral spines, 10-30 mm long.

Seeds flattened-ovoid, 34-40 mm long, 30-36 mm wide; sarcotesta orange-brown, not pruinose, 2-4 mm thick; fibrous layer absent; sclerotesta smooth. Spongy endocarp absent.

The Cycad Pages

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Written and maintained by Ken Hill 1998-2010
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