Hydriastele ramsayi (Becc.) Baker & Loo (2004: 67)

25. Hydriastele ramsayi (Becc.) Baker & Loo (2004: 67) View in CoL . Gulubia ramsayi Beccari (1910: 159) . Kentia ramsayi (Becc.) Beccari (1913: 148) . Gronophyllum ramsayi (Becc.) Moore (1963: 265) . Type:— AUSTRALIA. Northern Territory: Port Essington, Ramsay s.n. ( holotype MEL!, isotype FI)

Figure 55 View FIGURE 55 (line drawing). Figure 56 View FIGURE 56 (photo plate). Figure 57 View FIGURE 57 (map).

Solitary, robust palm to 30 m tall, bearing 9–17 leaves in crown. Stem 30–35 cm in diam., moderately ventricose. Leaf 1.5–3 m long including petiole; sheath ca. 100 cm long; petiole 30–80 cm long; rachis arcuate; leaflets 50–60 per side, arranged regularly, single-fold, ascending, linear acuminate to shallowly notched, ramenta lacking; middle leaflets ca. 80 × 2.5 cm. Inflorescence 50–60 cm long including 3.5–4.5 cm peduncle, branched to 2 orders, protandrous; prophyll often ± sigmoid, with pithy keels; rachillae ca. 31–32, not markedly sinuous; triads on average 5–6 mm apart, opposite and decussate. Staminate flower ca. 13 × 4 mm in bud (when dry), cream; stamens 5–6, exposed in bud. Pistillate flower ca. 5 × 4 mm in bud (when dry), green to cream, with free sepals and free petals with conspicuous, triangular and valvate tips. Fruit 12 × 6 mm (when dry), ellipsoid, red, with a distinct, dark, sclerotic zone encircling apical stigmatic remains (up to ca. 2 mm in diam.). Seed not seen; endosperm homogeneous.

Distribution:— The central northern portion of Australia’s Northern Territory including the Cobourg Peninsula and Melville Island. Also reported from the north eastern portion of the territory ( Dowe 2010).

Habitat:— Open eucalypt woodland dominated by seasonal drought and frequent wildfires, on sandstone slopes or flat ground on sandy soil, lowland.

Uses:— None recorded

Vernacular names:— None recorded

Conservation status:— Least Concern (LC). Hydriastele ramsayi has a relatively wide distribution (EOO> 92,000 km 2) and the AOO ( 552 km 2) is likely to be a low estimate due to an incomplete occurrence record.

Specimens examined:— AUSTRALIA. Northern Territory: Liverpool R. area, 25 May 1980, Craven 5918 (MEL, L!); Coburg Peninsula, Smith Point, 11°8’S, 132°9’E, 18 October 1971, Must 834 (K!, L!); 4 miles SE of Raffles Bay , 11°20’S, 132°26’E, 18 July 1961, Chippendale 8191 (K!); NW side of Cadwell R., ca. 25 km SE of Maningrida, 12°10’S, 134°25’E, 31 October 1973, Rodd 2921 (K!); Same locality as preceding, 12°10’S, 134°25’E, 31 October 1973, Rodd 2922 (K!); Arnhem Land, Oenpeilli, 12°18’S, 133°4’E, 1 October 1948, Specht 1113 (K!) GoogleMaps .

Notes:— Hydriastele ramsayi is the only member of Hydriastele endemic to Australia. It is an emergent palm distinguished by its robust, moderately ventricose stem, arching leaves with single-fold terminal leaflets that are shallowly notched at their tips, and protandrous inflorescences branched to 2 orders. In addition, the prophyll is often distorted, and the staminate flowers congenitally open, features that are shared with the Papuan H. biakensis although that species is not reported to have a ventricose stem and has protogynous inflorescence branched to 4 orders with markedly sinuous rachillae.

Hydriastele ramsayi is unusual in the genus (and Areceae in general) in occupying a seasonal, rather than everwet habitat. The species is also described in detail by Dowe (2010).