Shrubs; unarmed. Leaves alternate, sometimes opposite, pinnately compound (mature simple in Adenostoma); stipules persistent, free or adnate to petiole base, or reduced or absent (Adenostoma); venation pinnate. Flowers: perianth and androecium perigynous; epicalyx bractlets absent; hypanthium funnelform, cupshaped, or campanulate to cylindric; torus absent; carpels 1–5, basally connate or distinct (sometimes appearing connivent at base), free, styles terminal or lateral, distinct; ovules 1, basal, or 2 and collateral, 4–8, or 10–12 in 2 series, declining. Fruits achenes or aggregated follicles; styles persistent or not, not elongate.

Distribution

North America, nw Mexico, Eurasia

Discussion

Genera 4, species 9 (3 genera, 5 species in the flora).

The base chromosome number for Sorbarieae is x = 9. Spiraeanthus Maximowicz, with one species native to central Asia, also belongs here.

Selected References

None.

Lower Taxa

Adenostoma, Chamaebatiaria, Sorbaria

Key

1	Leaves simple (juvenile pinnatifid); stamens 10 or 15; fruits achenes within hypanthium.	Adenostoma
1	Leaves pinnately compound; stamens 17–110; fruits aggregated follicles	> 2
2	Leaves persistent, 1(–)2-pinnate-pinnatifid, leaflet margins entire or secondarily toothed-lobed; plants 6–20 dm.	Chamaebatiaria
2	Leaves deciduous, odd-pinnately compound, leaflet margins usually doubly serrate; plants 10–70 dm.	Sorbaria

"thin" is not a number.