Hydriastele pinangoides

Hydriastele (high-dree-Ah-STEL-eh) pinangoides (pih-nahn-go-EE-dehz)
Lake Kutubu, S. Highlands, Papua New Guinea. Photo by Dr. William J. Baker, Royal Botanic Gardens, Kew/Palmweb.
Scientific Classification
Genus: Hydriastele (high-dree-Ah-STEL-eh) Species: pinangoides (pih-nahn-go-EE-dehz)
Synonyms
Old name-Gronophyllum pinangoides (1985)
Native Continent
Oceania
Morphology
Habit: Clustering Leaf type: Pinnate
Culture
Survivability index
Common names
None.

Habitat and Distribution

Endemic to New Guinea.

Samarakoon's garden, Peradeniya, Sri Lanka. Photo by Philippe.

Distribution:—New Guinea and the islands of Misool, Waigeo, and Kobroor in the Aru archipelago. PETER PETOE, CHARLIE D. HEATUBUN & WILLIAM J. BAKER Phytotaxa 370 (1) © 2018 Magnolia Press.

Habitat:—Lowland or premontane rainforest on well-drained to water-logged soil. Primary or secondary forest on clay, limestone karst and volcanic soils, 0–1350 m. PETER PETOE, CHARLIE D. HEATUBUN & WILLIAM J. BAKER Phytotaxa 370 (1) © 2018 Magnolia Press.

Description

Solitary or clustering, slender understorey or midstorey palm to 7(–10) m tall, bearing 5–10 leaves per crown. Stem (0.8–)1.5–7.5 cm in diam. Leaf 50–157 cm long including petiole; sheath 15–52 cm long; petiole 15–54 cm long; leaflets 5–10(–13) per side, very variable in size and shape, irregularly arranged usually in 2 or 3 widely spaced groups, occasionally with portions of the lamina regularly pinnate, or very rarely the entire blade regularly pinnate, single- or multi-fold, broadly (rarely narrowly) cuneate, praemorse apically. Inflorescence (13–)18–30 cm long including 1.5–3 cm peduncle, branched to 1 order, protandrous; rachillae 2–5(–6), pink; triads spirally arranged. Staminate flower 6–8 × 1–3 mm in bud (when dry), reddish; stamens 6. Pistillate flower ca. 4 × 3.5 mm at fruiting stage, crimson, with free sepals and free petals with conspicuous, triangular tips. Fruit 10–16 × 4–8 mm when ripe, ellipsoid or cylindrical to fusiform, pink, red, purple or blackish, with a distinct, dark, sclerotic zone encircling apical stigmatic remains (up to about 2 mm in diam.). Seed 6–10 × 2–4 mm, ellipsoid; endosperm ruminate. PETER PETOE, CHARLIE D. HEATUBUN & WILLIAM J. BAKER Phytotaxa 370 (1) © 2018 Magnolia Press.

Culture

Cold Hardiness Zone: 10b

Comments and Curiosities

Notes:—Hydriastele pinangoides is a common, slender understorey to midstorey palm. It is distinguished by its leaves, which typically have 5–10 broadly cuneate leaflets on each side of the rachis arranged in 2 or 3 distinct groups, in combination with 18–30 cm long inflorescences (rarely as short as 13 cm) comprising 2–6 rachillae, and ruminate endosperm. Rarely, the leaflets can be more-or-less regularly arranged and narrowly cuneate prompting comparison with Hydriastele divaricata and H. simbiakii, but H. divaricata has divaricate leaflets and inflorescences with 1–2 rachillae, while H. simbiakii has flexible, usually leaning stems and 14–16 leaflets on each side of the rachis. Hydriastele pinangoides can be confused with some pinnate leaved forms of H. flabellata although this species has a shorter inflorescence (up to 15 cm long), spicate or with 2 rachillae (up to 3 rachillae is known from cultivation), and homogeneous endosperm. PETER PETOE, CHARLIE D. HEATUBUN & WILLIAM J. BAKER Phytotaxa 370 (1) © 2018 Magnolia Press.

Heatubun et al. (2018) discuss the morphology and delimitation of H. pinangoides in more detail. PETER PETOE, CHARLIE D. HEATUBUN & WILLIAM J. BAKER Phytotaxa 370 (1) © 2018 Magnolia Press.

Uses:—Stems used for spears, spearheads, bow material, arrowheads and for sewing thatch, the foliage used as roofing material. Planted as an ornamental and used for magic. PETER PETOE, CHARLIE D. HEATUBUN & WILLIAM J. BAKER Phytotaxa 370 (1) © 2018 Magnolia Press.

Vernacular names:—Tapolo (Pawaian), Gilaia (Waskuk), Kobu (Wagu), Ugarreh (Daga), Mara (Ambakanjah), Kupal (Gal), Tegradri (Irarutu), Bim, Kabim (Matbaat), Yali (Biyal), Seraach (Maibrat), Sêméngbrè (Hattam). manggam (Maprik, unknown dialect), tooma (Western Province, unknown dialect). PETER PETOE, CHARLIE D. HEATUBUN & WILLIAM J. BAKER Phytotaxa 370 (1) © 2018 Magnolia Press.

Conservation status:—Least Concern (LC; Heatubun et al. 2018). PETER PETOE, CHARLIE D. HEATUBUN & WILLIAM J. BAKER Phytotaxa 370 (1) © 2018 Magnolia Press.

Essig and Young (1985) accepted Gronophyllum leonardii, a nomen novum that they established to account for a name, Nengella brassii (Burret) Burret (syn. Leptophoenix brassii Burret), that could not be recombined in Gronophyllum due to a pre-existing publication of the name Gronophyllum brassii (Burret 1939). Having seen the type of Leptophoenix brassii, we are convinced that it falls within the wide range of variation that is encompassed by the complex species Hydriastele pinangoides, in particular in terms of leaf morphology, and we place it in synonymy accordingly. (W.J. Baker and A.H.B. Loo. 2004)/Palmweb. Editing by edric.

All together, not counting the current name, there have been 24 other accepted names for this species.