Flora of the Hawaiian Islands
Monocotyledon Literature for Pandanus tectorius
Brown & Brown, 1931; Smith, 1979; Wagner et al., 1990, 1999; Lorence & Wagner, 2019.
   Pandanaceae -- The Screw pine Family Bibliography
      Pandanus tectorius

Common name(s): screw pine, hala, pu hala
General Information
DistributionPacific islands including most of Polynesia, Melanesia, and Micronesia; also New Caledonia to northern Australia, New Guinea, west to the Philippines, Moluccas, and Java.In the Hawaiian Islands, indigenous to Ni`ihau, Kaua`i, O`ahu, Moloka`i, Lana`i, Maui, Hawai`i.

Click here for detailed USGS map by Jonathan Price
Small tree to 15 m tall, with an erect or ascending trunk to 35 cm in diameter, supported at base by several to numerous thick, rigid, somewhat prickly, ± branched prop roots, sometimes descending from branches, lateral branches dichotomous or trichotomous, often grouped in clusters or whorls.
Leaves crowded near branch ends, coriaceous, usually somewhat glaucous on abaxial surface, linear ensiform, usually arcuate, sometimes twisted, usually 80‒180 cm long, 4‒8 cm wide, midrib keeled on abaxial surface, ± with small retrorse or antrorse prickles, longitudinal veins evident, cross-veins usually obscure, margin with antrorse green or greenish brown tipped prickles to 4 mm long, apex attenuate.
Inflorescences terminal, pendent in fruit, pedunculate, bracteate, bracts white to cream colored. Staminate inflorescences (excluding proximal peduncle) usually 30‒45 cm long, fertile bracts usually 13‒18, spikes cream colored, oblong, compressed, to ca. 10 cm long, consisting of numerous crowded staminate phalanges, these columnar; stamens racemose, often 12‒18(‒30) per cluster, filament distinct, 1‒3 mm long, pollen white; pistillate inflorescence a suberect solitary head, usually closely enveloped by bracts, each head globose to ovoid ellipsoid, ca. 5 cm in diameter at anthesis. Pistillate spadices ripening to 10‒20 cm long and 10‒18 cm in diameter, phalanges often 40‒80 per head, ripe phalanges usually obovoid, usually 4‒7 cm long, slightly compressed, apex low convex to subtruncate, each carpel apex distinct, capped by the ± slightly elevated stigma, stigma ovate deltate to reniform, usually 1‒2 mm wide.
Phalanges forming polydrupes with usually 5‒11 locules, pericarp at least proximally yellow, orange, or red when ripe, slightly fleshy fibrous below, distally similar in color or greenish, upper mesocarp with spongy pith and, with age, with cavities and fibrous, lower mesocarp fibrous, endocarp reddish brown, bony.
Seed chambers fusiform ellipsoid, usually 8‒15 mm long.
2n = ca. 51*, 54*, 60*.
Pandanus tectorius is an extremely widespread and variable species occurring on many if not most Pacific islands including atolls and high islands. We consider the taxa described from the Marquesas Islands by Brown, St. John, and Martelli to be synonyms of Pandanus tectorius.
David Lorence