Spiraeanthemum A.Gray

Shrubs or small to medium-sized trees. Twigs somewhat thickened at nodes. Indumentum of simple hairs with secretory glands on leaf surface and veins visible as red dots. Leaves simple, opposite and decussate, the margin entire or crenate-serrate; domatia in axils of veins often present. Stipules interpetiolar, one pair per node, simple, triangular-ovate, caducous. Inflorescences axillary and solitary or occasionally two subunits serially inserted, rarely terminal, paniculate, with branching at proximal nodes opposite and decussate and at peripheral nodes ± alternate, many-flowered, with peduncles 1/5-1/2 of total length, the axes bearing small caducous bracts at nodes. Flowers 3-5-, mostly 4-merous, apetalous, pedicellate, unisexual and plants dioecious. Sepals valvate, subcoriaceous, connate for 1/4-1/2 of their length. Stamens with filaments subulate, glabrous and anthers transverse-oval, incised at apex and base, in female flowers reduced to about half size and probably sterile. Disc in male flower lobed, the number of lobes equal to the number of stamens but united in pairs, the pairs separated by the alternipetalous stamens and with the alternisepalous stamens deeply impressed on the outer surface, ± closely adpressed to form an inverted cone in centre of flower; in female flower lobed, the lobes either free, oblong, as many as and alternating with the filaments, or some or all lobes united in pairs, connate inside alternisepalous stamens. Ovary in male flower absent; in female flower superior, apocarpous, carpels 2-5 and usually equal to the number of sepals, ovoid, hairy, each with 2 ovules; styles continuous with ovary, terete, glabrous or with some hairs in lower part only; stigma terminal, inconspicuous, clavate, papillose. Fruit multiple, a follicetum with (2-)3-5 free follicle-like fruitlets, attached to receptacle at base and each dehiscing along the full length of the adaxial suture, the valves boat-shaped, stiff-coriaceous, their margins minutely thickened, the styles, calyx and sometimes stamens persistent. Seeds 1-few per carpel, glabrous, with a small pointed wing at both ends.

In rain forest; in New Britain, New Ireland and the Solomon Islands (in-cluding Bougainville) between 700 and 2250 m, elsewhere in the Pacific also occasionally at lower altitudes and in drier vegetation types.