Pandanaceae

Callmander, Martin W., Lowry Ii, Porter P., Forest, Félix, Devey, Dion S., Beentje, Henk & Buerki, Sven, 2012, Benstonea Callm. & Buerki (Pandanaceae): characterization, circumscription, and distribution of a new genus of screw-pines, with a synopsis of accepted species, Candollea 67 (2), pp. 323-345 : 326-327

Key to the genera of Pandanaceae (adapted from STONE,1974; STONE & al., 1998)

1. Pistillate inflorescence (infructescence) a panicle; leaves in 4 spiral rows; flowers with a perianth-like cupule ........ ......................................................................... Sararanga

1a. Pistillate inflorescence (infructescence) a cephalium or a raceme or pseudo-umbel of cephalia; leaves in 3 spiral rows; flowers without a perianth-like cupule................. 2

2. Liana; fruit a berry; carpels multi-ovulate (ovules much more numerous than 3); seeds generally free and germinating outside the fruit................................... Freycinetia

2a. .......................................................................................... Acaulescent shrubs to large trees; fruit a drupe with a hard bony endocarp; carpels uniovulate, rarely 2-3 ovulate; seed bound to endocarp and always germinating within the fruit ................................................................ 3

3. Drupes with endocarp not extending between the seed locules, but replaced by the mesocarp extending from the apex to the base; stigmas two, forming a cross at the apex of the pileus; staminodia present at the base of each drupe, each comprising a filament and an anther with four sterile pollen sacs ............................................. Martellidendron

3a. Drupes with endocarp extending between the seed locules surrounded by mesocarp; stigma(s) 1 to numerous, of various shapes but never two and forming a cross at the apex of the pileus; staminodia rarely and abnormally present............................................................................. 4

4. Carpels either free or connate into multicarpellate, severalseeded drupes; stigmas always on the adaxial side of the style, variable in shape but usually not sharp and linear (but if so with stigmas always on the abaxial side of the style); staminate flower with several connate stamens, i.e. borne on a stemonophore, rarely free (in P.epipythicus Martelli and P. pentodon Ridl. )...................................... Pandanus

4a. Carpels always free, forming one-seeded drupes; stigmas always positioned on abaxial side of the style, sharp, linear; staminate flower reduced to one stamen, or in triads, free or very slightly joined at the base............. Benstonea