Rosaceae tribe Sorbarieae
in N. L. Britton et al., N. Amer. Fl. 22: 239, 256. 1908.
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, cup-shaped, 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.
North America, nw Mexico, Eurasia.
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.
|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|