Hydriastele procera

Hydriastele (high-dree-Ah-STEL-eh) procera (proh-SAH-rah)
Hydriastele procera. A–C. Habit. All from Triton Bay, western New Guinea. All photos: Charles Humfrey. PETER PETOE, CHARLIE D. HEATUBUN & WILLIAM J. BAKER Phytotaxa 370 (1) © 2018 Magnolia Press.
Scientific Classification
Genus: Hydriastele (high-dree-Ah-STEL-eh) Species: procera (proh-SAH-rah)
Synonyms
None set.
Native Continent
Oceania
Morphology
Habit: Solitary Leaf type: Pinnate
Culture
Survivability index
Common names
None.

Habitat and Distribution

Distribution:—West Papua Province in western New Guinea.

Habitat:—Limestone cliffs and crags, 0–200 m.

Hydriastele procera. A–C. Habit. All from Triton Bay, western New Guinea. All photos: Charles Humfrey. PETER PETOE, CHARLIE D. HEATUBUN & WILLIAM J. BAKER Phytotaxa 370 (1) © 2018 Magnolia Press.

PETER PETOE, CHARLIE D. HEATUBUN & WILLIAM J. BAKER Phytotaxa 370 (1) © 2018 Magnolia Press.

Description

Solitary and gregarious, robust palm to 30 m tall, bearing 10–15 leaves in crown, crown spherical. Stem 20–30 cm in diam., moderately ventricose; internode 6–25 cm long. Leaf (1–)2–4 m long including petiole; sheath ca. 100 cm long, with some white bloom, crownshaft not seen; petiole 15–20 cm long, flattened adaxially; rachis straight or slightly drooping; leaflets 40–61 per side, arranged regularly, single-fold, pendulous, linear; with ramenta attached to the basal portion of the abaxial side of the midrib; middle leaflets 70–90 × 3–4 cm, acuminate to briefly bifid apically; terminal leaflets acuminate to briefly bifid apically. Inflorescence 55–90 cm long including 7–12 cm peduncle, branched to 2 or 3 orders, protandrous; rachillae 23–40, about 2–3 mm in diam.; triads 6–7 mm apart, opposite and decussate; about 6 inflorescences present. Staminate flower 14–16 × 3–5 mm in bud (when dry); stamens 6. Pistillate flower about 6–6.5 × 3 mm in bud, with free sepals and free petals with conspicuous, triangular and valvate tips. Fruit 10–15 × 6–7 mm when ripe (and dry), ellipsoid, with a distinct, dark, sclerotic zone encircling apical stigmatic remains (up to about 3.5 mm in diam. when dry). Seed about 9.5 × 5 (when dry), ellipsoid; 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 procera is a tall and robust palm with a moderately ventricose trunk that often occurs gregariously on limestone. The species is distinguished by its spherical crown of more-or-less straight leaves in combination with protandrous inflorescences (ca. six inflorescences are present at any given time) with relatively slender rachillae (ca. 2–3 mm in diam.), staminate flowers with six stamens, and relatively large fruits (10–15 × 6–7 mm when dry). Hydriastele procera is most similar to H. wosimiensis, but that species has up to 26 inflorescences, thicker rachillae (ca. 3.5 mm in diam.), staminate flowers with 12 stamens and smaller fruits (7.5–9.5 × 5–5.5 mm when dry). PETER PETOE, CHARLIE D. HEATUBUN & WILLIAM J. BAKER Phytotaxa 370 (1) © 2018 Magnolia Press.

Uses:—Flooring.