Spiraea L.

Deciduous or semi-deciduous, large, sometimes suckering shrubs, not armed; stems usually erect; young shoots often brittle. Lvs usually distributed along stems, sometimes in fascicles on short shoots, usually simple, sometimes lobed, entire, dentate, crenate or serrate, usually shortly petiolate; stipules 0. Infl. a lateral or terminal panicle, corymb or umbel. Fls 5-merous, small, shortly pedicellate, ☿ or rarely unisexual. Hypanthium cup-shaped or turbinate. Epicalyx 0. Sepals small, connate at base, usually persistent. Petals 5, usually > sepals, ± spreading, white to crimson. Stamens 15–60, inserted on margin of calyx tube. Ovary superior; carpels (3)–5–(8), free; styles (3)–5–(8); ovules several in each locule. Fr. of coriaceous or leathery follicles; seeds several per follicle; very small.

[From: Webb et al. (1988) Flora of New Zealand. Volume 4.]