Hydriastele apetiolata

Hydriastele (high-dree-Ah-STEL-eh) apetiolata (ah-peh-tee-oh-LAH-tah)
Hydriastele apetiolata. A–B, D. Habit. C. Infructescence. All from Baker et al. 884. All photos: W.J. Baker. PETER PETOE, CHARLIE D. HEATUBUN & WILLIAM J. BAKER Phytotaxa 370 (1) © 2018 Magnolia Press.
Scientific Classification
Genus: Hydriastele (high-dree-Ah-STEL-eh) Species: apetiolata (ah-peh-tee-oh-LAH-tah)
Synonyms
None set.
Native Continent
Oceania
Morphology
Habit: Clustering (Soboliferous) Leaf type: Pinnate
Culture
Survivability index
Common names
None.

Habitat and Distribution

Distribution:—Known from two distinct localities on the southern coast of New Guinea.

Hydriastele apetiolata. A–B, D. Habit. C. Infructescence. All from Baker et al. 884. All photos: W.J. Baker. PETER PETOE, CHARLIE D. HEATUBUN & WILLIAM J. BAKER Phytotaxa 370 (1) © 2018 Magnolia Press.

Habitat:—Primary or secondary lowland rainforest, 20–50 m..

Description

Clustering, moderately slender palm to 6 m tall, bearing 7–10 leaves per crown. Stem 4.5–6 cm in diam. Leaf to 125 cm long; sheath ca. 60 cm long; petiole lacking; leaflets 23–26 per side, arranged regularly; basal leaflets single-fold, linear and somewhat grouped, obliquely or truncately praemorse apically; terminal leaflets comprising 4–6 folds, cuneate, truncately praemorse apically; juvenile leaves entire-bifid, with or without petiole, with lamina 100–130 cm long. Inflorescence 25–35 cm long including 3.5–5.5 cm peduncle, branched to 2 orders, protogynous; primary branches ca. 8, to 27.5 cm long, bearing up to 3 rachillae each; triads opposite and decussate. Staminate flower 11–12 × 5–6 mm in bud; stamens 6–8. Pistillate flower 2–3 × 2.5–3 mm in bud, with free sepals and free, ± rounded, low petals. Fruit 7.4–9.4 × 6.6–8.2 mm when ripe, subglobose, red, with inconspicuous stigmatic apical remains lacking encircling dark sclerotic zone. Seed 5.1–7.2 × 5–6.8 mm, globose to subglobose; 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 apetiolata is a midstorey palm with a slender stem, distinguished by its regularly pinnate, apetiolate adult leaves and entire-bifid juvenile leaves (petiolate or apetiolate in the juvenile). The combination of entire juvenile leaves and pinnate adult leaves is not known from other slender understorey to midstorey species of Hydriastele although a similar pattern in leaf dimorphism is reported for some of the bigger tree taxa, e.g. Hydriastele manusii (Fig. 45) and H. boumae (Baker & Loo 2004). More details are given by Petoe et al. (2018). PETER PETOE, CHARLIE D. HEATUBUN & WILLIAM J. BAKER Phytotaxa 370 (1) © 2018 Magnolia Press.