Pandanaceae

Abstract

Trees, shrubs or woody climbers; stems usually sympodially branched, annulate with leaf scars; adventitious roots sometimes branched and divaricate, functioning as prop roots or clasp roots, or, if early aborted, as spines or protuberances. (Leaves spirally arranged, 3-ranked (Freycinetia and Pandanus) or 4-ranked (Sararanga), linear-ensiform, entire but armed on margins and the adaxial face of midrib with prickles, sometimes also in the adaxial face of lateral pleats, rarely unarmed. Inflorescences terminal, sometimes lateral or axillary, usually unisexual, at first erect but often soon nodding or pendent, in spikes or racemes of spikes in Pandanus, in pseudoumbels (rarely racemes) of spikes in Freycinetia,and in repeatedly branched panicles in Sararanga; lower bracts foliaceous, upper bracts variously coloured, sometimes fragrant and slightly sweet. Flowers strictly unisexual (most Pandanus), or with vestiges of the other sex, without perianth. Staminate inflorescence: flowers distinct in Sararanga and in most Pandanus, generally indistinct in Freycinetia; filaments smooth or papillate; anthers longitudinally dehiscent, retuse or acuminate. Pistillate inflorescence: flowers composed of one or several carpels; styles absent to distinct, sometimes spiniform (some Pandanus); stigmas reniform or hippocrepiform, sometimes elongated (some Pandanus); ovules anatropous, bitegmic. Fruit a drupe (Pandanus) or berry (Freycinetia, Sararanga). Seeds straight in Pandanus and Sararanga, straight or variously curved in Freycinetia; seed coat thin and membranous in Pandanus, thickened in Sararanga and Freycinetia; embryo small and straight; endosperm copious, oily, in Freycinetia starchy.