Hydriastele costata Bailey (1898: 129)

Petoe, Peter, Heatubun, Charlie D. & Baker, William J., 2018, A monograph of Hydriastele (Areceae, Arecaceae) in New Guinea and Australia, Phytotaxa 370 (1), pp. 448-450 : 448-450

23. Hydriastele costata Bailey (1898: 129) . Type:— AUSTRALIA. Queensland: Cape York Peninsula, Somerset , Jardine s.n. (holotype BRI)

Kentia costata Beccari (1877: 36) . Gulubia costata (Becc.) Beccari (1885: 134) . Type:— INDONESIA. Maluku Province: Aru Islands, Wokam, Beccari s.n. (holotype FI!, isotype K!).

Gulubia costata var. minor Beccari (1885: 135) . Type:— INDONESIA. Papua Province: Yapen, Ansus , Beccari s.n. (holotype FI!).

Gulubia costata var. pisiformis Beccari (1885: 136) . Type:—Cultivated in Bogor Botanic Gardens, Beccari s.n. (holotype FI!). Pinanga pisiformis Teijsm. ex Beccari (1885: 136) . nom. illeg.

Kentia microcarpa Warb. ex Schumann & Lauterbach (1900: 207) . Lectotype (designated by Baker & Loo [2004]):— PAPUA NEW GUINEA. Morobe Province: Finschhafen, Lauterbach 751 (L!, isolectotype FI).

Kentia costata var. microcarpa Lauterb. & K.Schum. ex Schumann & Lauterbach (1900: 207) . nom. illeg.

Gulubia affinis Beccari (1923: 444) . Type:— PAPUA NEW GUINEA. East Sepik Province: Hunstein Mts., Ledermann 8228 (holotype B†).

Gulubia costata var. gracilior Burret (1936a: 81) . Type :— PAPUA NEW GUINEA. Western Province : Oriomo River , Woroi, Brass 5887 (holotype B†, isotypes A, BO, BRI!, NY!).

Figure 49 (line drawing). Figure 50 (photo plate). Figure 51 (map).

Solitary, robust to very robust palm, to 35 m tall bearing 12–25 leaves in crown, crown distinctively spherical. Stem 15–35 cm in diam. Leaf 2.4–5.5 m long including petiole; sheath 50–180 cm long; petiole 10–60 cm long; rachis straight or slightly drooping; leaflets 58–75 per side, arranged regularly, single-fold, pendulous, linear and acuminate to briefly bifid apically; with ramenta attached to the basal portion of the abaxial side of the midrib; middle leaflet 90–130 × 3–5 cm. Inflorescence 58–100 cm long including 5–25 cm peduncle, branched to 2 or 3 orders, apparently protogynous; triads 1–5 mm apart, opposite and decussate. Staminate flower 6–8 × 2–3 mm in bud, white to brownish; stamens 6, not exposed in bud. Pistillate flower ca. 2 × 2.5–3 mm in bud, cream, with free sepals and free, low and ± rounded petals. Fruit ca. 8–10 × 6 mm when ripe, ellipsoid, ripening through reddish brown to dark purple or blackish maroon, with conspicuous longitudinal white-greyish stripes, with inconspicuous sclerotic zone encircling apical stigmatic remains (up to ca. 1 mm in diam.). Seed ca. 5.5 × 4.5 mm, ellipsoid, costate; endosperm homogeneous.

Distribution:— Widely distributed in the north eastern portion of Cape York Peninsula in Queensland, Australia, and throughout lowland New Guinea and adjacent islands. Also reported from the Bismarck Archipelago ( Essig 1982).

Habitat:— Primary or secondary lowland rainforest often on swampy ground, or more infrequently lower montane forest on less waterlogged ridges and slopes, 0–700 m.

Uses:— Stems and leaves used for flooring and house construction, leaf sheaths used as basins for water buckets, carrying baskets, sago containers and plates, indumentum used as firelighter and old inflorescences as brushes. The palm heart is consumed. Commonly planted near villages.

Vernacular names:— Avos/Afos (Miyah), Bay (Marap), Kaparo (Wandamen), Korr (Jal), Mabla (Orne), Oratare (Sumuri), Poi (Wapi), Tab (Timbunke), Tabavo Nyi (Unknown dialect, North Cyclops Mts. area), Tabuh (Maprik), Yawa (Ambakanja).

Conservation status:— Least Concern (LC). Hydriastele costata is widely distributed (EOO> 1,360,000 km 2) and common. The AOO (136 km 2) is higher than for most other species within the genus yet still likely to be a conservative figure.

Specimens examined:— AUSTRALIA. Queensland: Cape York Peninsula, Iron Range, 12°45’S, 143°15’E, 16 June 1948, Brass 19207 (BRI, K!, L!); Cape York Peninsula, Iron Range, 30 m, 12°45’S, 143°15’E, 17 October 1974, Irvine 1020 (BRI, CNS, L!); Same locality as preceding, 12°45’S, 143°15’E, 17 September 1974, Irvine 1011 (BRI, CNS, K!). INDONESIA. Maluku Province: Aru Islands: Wokam (Vokan), 5°45’S, 134°30’E, 1873, Beccari s.n. (FI!, K!); Papua Province: Nabire, Wanggar, Bumi River, 10 m, 3°30’S, 135°27’E, 9 February 2001, Heatubun 340 (AAU, K!, MAN); Mimika, Timika, Road from Mile 21/Timika to Port, 5 m, 4°41’S, 136°52’E, 12 February 1998, Baker et al. 836 (AAU, BH, BO, K!, L, MAN); Yapen, Ansus, 1°43’S, 135°49’, 1875, Beccari s.n. (FI!); Aria, near Uta, 4 m, 4°32’S, 136°0’E, 28 June 1941, Aet 386 (BO, K!, L!, SING); Northern Biak, Wari village, 10 m, 0°55’S, 135°55’E, 10 September 1998, Maturbongs 573 (BO, K!, MAN); Jayapura, North Cyclops Mts., 15 m, 2°30’S, 140°32’E, 30 January 2001, Desianto 21 (AAU, K!, MAN); Manokwari Distr., Bintuni Subdistr., in hill forest inside property line of BP, beside trail between Saengga & Tanah Merah villages, 20 m, 2°27’S, 133°7’E, 19 February 2002, Maturbongs 733 (BO, K!, LAE, MAN); Arso Distr., Tami River, Yawara, 100 m, 2°51’S, 140°48’E, 15 March 2002, Gusbager 13 (AAU, K!, LAE, MAN); West Papua Province: Sorong distr., Klasaman, Klabainem, 10 m, 0°54’S, 131°20’E, 29 January 2002, Heatubun 374 (K!, MAN); Manokwari, Nuni, Sungei Asiai, between Mt. Manggombo and Mt. Marwadibau, 15 m, 0°45’S, 133°56’E, 18August 1995, Zona 681 (FTG, K!); Tamrau Mountains, furthest end of the Sorong-Manokwari road, 547 m, 0°49’S, 132°31’E, 23 January 2013, Gardiner 410 (AAU, BO, K!, L, MAN); Wandammen Peninsula, Wasior distr., Manokwari Regency near Dotir village, 11 km N of Wasior, near the confluence of the Mawoi River and the Yois River, 20 m, 2°37’S, 134°29’E, 20 February 2000, Baker et al. 1042 (BO, BRI, K!, L, MAN); Wandammen Peninsula, Wasior distr., Manokwari Regency; Kowi, near Wondiwoi village, ca. 9 km S of Wasior, 570 m, 2°48’S, 134°32’E, 23 February 2000, Baker et al. 1052 (AAU, BO, BRI, K!, L, MAN). PAPUA NEW GUINEA. Central Province: Road from Mori River to Yano Village, 15 km NE of Cape Rodney, 30 m, 10°4’S, 148°32’E, 5 September 1969, Pullen 8218 (BH, CANB, L!, LAE); East Sepik Province: Pieni River, near Walwali Village, Aitape Subdistr., 30 m, 3°11’S, 142°4’E, 20 June 1961, Darbyshire 7971 (A, BRI, L!, LAE); Prince Alexander Range, SE side of Mt. Turu above Ambakanja Village, 700 m, 3°37’S, 143°22’E, 25 August 1959, Pullen 1597 (L!, LAE); 5 miles N of Timbunke, 30 m, 4°7’S, 143°30’E, 12 October 1959, Pullen 1717 (CANB, L!, LAE); Gulf Province: Kikori Distr., Bank of Kikori River near Kopi, 13 km N of Kikori, 40 m, 7°22’S, 144°14’E, 19 November 2000, Baker et al. 1095 (AAU, K!, LAE); Madang Province: Josephstall FMA area, along footpath towards Morasapa, W of expedition Camp 1 (‘Kumamdeber’), and to lower slopes N of the trail, 161.54 m, 4°28’S, 145°1’E, 29 July 1999, Takeuchi 13522 (A, K!); Lower Ramu valley, quarter mile N of Josephstaal airstrip, 4°44’S, 145°1’E, 2 September 1958, Pullen 1082 (A, CANB, L!); Milne Bay Province: Peria Creek, Kwagira River, 50 m, 9°35’S, 149°26’E, 25 August 1953, Brass 24185 (A, K!, L!, LAE); Inland from Miadeba, Normanby Island, 250 m, 9°52’S, 150°55’E, 24 November 1976, Croft 68903 (L!, LAE); Morobe Province: Finschhafen, 5 August 1890, Lauterbach 751 (FI, L!); Boana, 6°26’S, 146°49’E, 20 September 1940, Clemens 41839 (K!); Kajabit Mission Vicinity, 6°15’S, 146°16’E, 7 September 1939, Clemens 10674 (MICH, K!); Kajabit Mission Vicinity, 275 m, 6°15’S, 146°16’E, 21 September 1939, Clemens 10702 (K!, MICH); Sattelberg, Hillsbach, 2000 m, 6°29’S, 147°47’E, 28 October 1935, Clemens 660 (L!); Unknown Province: June 1885, Bauerlen s.n. (MEL!); British New Guinea [now SE New Guinea], 1890, Loria s.n. (K!); Western Province: Woroi, Oriomo River, 8°49’S, 143°7’E, January 1934, Brass 5887 (A, B†, BO, BRI!, NY!). CULTIVATED. INDONESIA. Bogor Botanic Gardens, Beccari s.n. (Fl!).

Notes:— Hydriastele costata is the commonest lowland tree palm in New Guinea. It is immediately recognisable as a canopy emergent with a distinctive, spherical crown of more-or-less straight leaves with pendulous leaflets. Its highly distinctive longitudinally striped fruits with costate seeds are not seen in any other member of the genus. Hydriastele costata has a similar habit to H. procera and H. wosimiensis from the Longispatha group.

Hydriastele costata appears to be most similar to H. moluccana , a rarely collected species known from North Maluku Province in Indonesia. Hydriastele costata is distinguished from this species primarily by its striped fruits with costate seeds (see Essig 1982).

PALAUENSIS GROUP

Robust palms, leaves strongly arching with ascending leaflets, inflorescences protandrous or protogynous, staminate flowers with 6 stamens that are congenitally exposed in bud, i.e. the margins of the staminate petals do not meet. Palau, the Biak Islands and Australia.

Figures

FIGURE 49. Hydriastele costata. A. Habit. B. Leaf apex. C. Infructescence. D. Portion of rachilla with triads (pistillate flowers not visible). E. Staminate flower whole and in longitudinal section. F. Pistillate flower. G. Portion of rachilla with fruit. H. Fruit whole, in longitudinal section, and in transverse section. Scale bar: A = 1.8 m; B = 6 cm; C = 9 cm; D = 1 cm; E = 7 mm; F, H = 5 mm; G = 2 cm.A from Prati Valley, August 1995; B–H from Baker et al. 836. Drawn by Lucy T. Smith.

FIGURE 50. Hydriastele costata. A. Habit. B. Crown. C. Portions of rachillae with triads. D. Portion of inflorescence with pistillate flowers. E. Portion of rachilla with fruit.A from Biak Island; B from Lae Botanic Garden, Papua New Guinea; C–D from Baker et al. 1042; E from Baker et al. 1052. All photos: W.J. Baker.

FIGURE 51. Distribution map of the Moluccana group of Hydriastele in New Guinea, Australia and adjacent islands.