Hydriastele manusii

Hydriastele (high-dree-Ah-STEL-eh) manusii (mah-NOO-see)
Hydriastele manusii. A. Habit. B. Juvenile habit. All from Manus Island. All photos: Axel Dalberg Poulsen. PETER PETOE, CHARLIE D. HEATUBUN & WILLIAM J. BAKER Phytotaxa 370 (1) © 2018 Magnolia Press.
Scientific Classification
Genus: Hydriastele (high-dree-Ah-STEL-eh) Species: manusii (mah-NOO-see)
Synonyms
None set.
Native Continent
Oceania
Morphology
Habit: Solitary Leaf type: Pinnate
Culture
Survivability index
Common names
None.

Habitat and Distribution

Distribution:—Manus Island in the

Hydriastele manusii. A. Habit. B. Juvenile habit. All from Manus Island. All photos: Axel Dalberg Poulsen. PETER PETOE, CHARLIE D. HEATUBUN & WILLIAM J. BAKER Phytotaxa 370 (1) © 2018 Magnolia Press.

Bismarck Archipelago.

Habitat:—Premontane rainforest on steep slopes, 600–740 m. PETER PETOE, CHARLIE D. HEATUBUN & WILLIAM J. BAKER Phytotaxa 370 (1) © 2018 Magnolia Press.

Description

Solitary, moderately robust palm to 20 m tall, bearing 9–13 leaves in crown. Stem 10–15 cm in diam.; internode not seen. Leaf about 1.5–2 m long including petiole; sheath about 100 cm long, with white bloom, crownshaft about 150 × 15 cm; petiole about 10 cm long, channelled adaxially; rachis arcuate; leaflets about 40 per side, arranged regularly, ascending and ± drooping at their tips, linear, truncately praemorse apically, lacking ramenta; basal leaflets multi-fold; middle leaflets 60–66 × 2–3 cm, single-fold; terminal leaflets comprising 2–4 folds. Inflorescence 60–80 cm long including 20–22 cm peduncle, branched to 2 orders, protandrous; rachillae 12–15; triads on average 3–4 mm apart, opposite and decussate; 1–5 inflorescences present. Staminate flower 6–7 × 3–4 mm at anthesis (when dry); stamens 6. Pistillate flower 3.5–4 × 2.5–3 mm in bud (when dry), with free sepals and free petals with conspicuous, triangular and valvate tips. Fruit about 12 × 4 mm (when dry), elongate and curved (when dry), red, with a rather inconspicuous sclerotic zone encircling apical stigmatic remains (up to about 1.5 mm in diam. when dry). Seed about 8.3 × 3.5 mm (when dry), curved; endosperm homogeneous. PETER PETOE, CHARLIE D. HEATUBUN & WILLIAM J. BAKER Phytotaxa 370 (1) © 2018 Magnolia Press.

Culture

Cold Hardiness Zone: 10b

Comments and Curiosities

Notes:—Hydriastele manusii is a moderately robust canopy palm distinguished by its relatively short (1.5–2 m long), arching leaves with equally short (ca. 10 cm long) petioles. The species is further distinguished by its inflorescences with 20 cm long peduncles and relatively few (12–15) rachillae. Confusion with other species is unlikely. PETER PETOE, CHARLIE D. HEATUBUN & WILLIAM J. BAKER Phytotaxa 370 (1) © 2018 Magnolia Press.