Family Siphonodontaceae

Siphonodontaceae Gagnep. & Tardieu

Alternatively Capusiaceae Gagnep.~ Celastraceae

Habit and leaf form. Trees, or lianas. Self supporting, or climbing. Mesophytic. Leaves alternate; distichous; non-sheathing; simple. Lamina entire; pinnately veined. Leaves exstipulate.

Stem anatomy. Secondary thickening developing from a conventional cambial ring, or anomalous (?). Xylem with libriform fibres.

Reproductive type, pollination. Fertile flowers hermaphrodite. Plants hermaphrodite.

Inflorescence, floral, fruit and seed morphology. Flowers small; regular; 5 merous; cyclic; tetracyclic. Free hypanthium absent. Hypogynous disk present.

Perianth with distinct calyx and corolla; 10; 2 whorled; isomerous. Calyx 5; 1 whorled; polysepalous; regular. Corolla 5; 1 whorled; polypetalous; regular.

Androecium 5. Androecial members free of the perianth (the filaments closely appressed to the disk, the anthers forming a five-rayed star at the top); free of one another; 1 whorled. Androecium exclusively of fertile stamens. Stamens 5; isomerous with the perianth; oppositisepalous; alternating with the corolla members. Anthers dehiscing via longitudinal slits. Pollen grains aperturate; 3 aperturate; porate.

Gynoecium (8–)10(–12) carpelled. Carpels increased in number relative to the perianth. The pistil (8–)10(–12) celled. Gynoecium syncarpous; synstylovarious, or eu-syncarpous; superior to partly inferior (embedded in the hemispherical disk). Ovary (8–)10(–12) locular. Locules secondarily divided by ‘false septa’; each divided horizontally into one-ovulate locelli (each with one septum, dividing it into two superposed locelli). Gynoecium non-stylate. Stigmas represented by 5 stigmatic lines and tufts. Placentation axile. Ovules 2 per locule (one in each locellus); pendulous and ascending (the upper ascending, the lower pendulous); and their locelli superposed.

Fruit (hard-) fleshy; indehiscent; a drupe. The drupes with separable pyrenes (these bony, about 20, radiating). Seeds endospermic (the endosperm bony).

Geography, cytology. Sub-tropical to tropical. Southeast Asia, Malaysia, Northeast Australia.

Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Santaliflorae; Celastrales. Cronquist’s Subclass Rosidae; Celastrales. APG 3 core angiosperms; core eudicot; Superorder Rosanae; fabid; Order Celastrales (as a synonym of Celastraceae).

Species 5. Genera 1; only genus, Siphonodon.