Herbs, shrubs, or trees, with alternate (in some exotic genera opposite), simple or compound leaves, and regular perfect or rarely polygamo-dioecious flowers. Stipules commonly present, sometimes large. Calyx free from or adnate to the ovary, 5-lobed (rarely 4-9-lobed), often bracteolate. Disk adnate to the base of the calyx. Petals equal in number to the calyx-lobes, distinct, or none. Stamens usually numerous, distinct; anthers small, 2-celled. Carpels 1-∞, distinct, or adnate to the calyx. Ovary 1-celled or rarely imperfectly 2-celled; style terminal or lateral. Ovules 1, 2, or several, anatropous. Fruit various, mostly follicles or achenes; endosperm none, or rarely copious.

A family comprising about 75 genera and more than 1200 species, of wide geographic distribution.

A. Fruit of 1-5 dehiscent follicles.

* Carpels alternate with the sepals; stipules deciduous or none.

Carpels, if more than 1, united below; seeds with endosperm (Neillieae).

1.

Opulaster.

Carpels normally 5, distinct; seeds without endosperm (Spiraeeae).

Flowers perfect; shrubs with simple leaves.

2.

Spiraea.

Flowers dioecious; tall herbs with pinnately 2-3-compound leaves.

3.

Aruncus.

** Carpels opposite the sepals; stipules persistent (Sorbarieae).

Petals obovate or spatulate, imbricated; leaves pinnate.

4.

Schisonotus.

Petals strap-shaped, convolute in the bud; leaves trifoliolate.

5.

Porteranthus.

B. Fruit indehiscent, of achenes or drupelets.

* Carpels not enclosed in the fleshy calyx-tube (hypanthium).

I. Fruit of dry achenes.

Ovaries 2-ovuled (Ulmarieae).

6.

Filipendula.

Ovaries 1-ovuled.

Seed pendulous or ascending, borne in the ovary opposite to the base of the style.

Style articulated with the ovary; calyx-tube from campanulate to nearly flat (Potentilleae).

Style terminal or nearly so; ovule and seed pendulous.

7.

Potentilia.

Style lateral; ovule and seed ascending.

Herbs; achenes glabrous.

Achenes numerous; stamens about 20.

Leaves odd-pinnate.

Receptacle not enlarged in fruit; petals yellow, obtuse or refuse.

8.

Argentina.

Receptacle somewhat enlarged in fruit, spongy; petals red, acute or acuminate.

9.

Comarum.

Leaves 3-foliolate; receptacle much enlarged in fruit.

Receptacle not pulpy; petals yellow.

10.

Duchesnea.

Receptacle very pulpy: petals white or pinkish.

11.

Fragaria.

Achenes 10-15; stamens 5; leaves 3-foliolate.

12.

Sibbaldia.

Shrubs; achenes hairy.

Style filiform; leaves 3-foliolate.

13.

Sibbaldiopsis.

Style club-shaped; leaves pinnate.

14.

Dasiphora.

Style nearly basal; ovule and seed ascending.

Stamens numerous; flowers bracteolate; leaves pinnate.

15.

Drymocallis.

Stamens 5; flowers ebracteolate; leaves 2-3-ternately compound.

16.

Chamaerhodos.

Style not articulated with the ovary; calyx-tube urn-shaped or cup-shaped, contracted at the

throat or mouth.

Style nearly basal; inflorescence cymose; petals none (Alchemilleae).

Perennial herbs; stamens 4, alternate with the sepals.

17.

Alchemilla.

Small annual herbs; stamen 1, opposite a sepal, rarely 2-5.

18.

Aphanes.

Style terminal; inflorescence spicate, racemose or capitate (Sanguisorbeae).

Calyx-tube not prickly; petals none.

Stamens 2-4, not declined; pistil 1.

Perennial herbs; stigma papillose; leaflets toothed.

19.

Sanguisorba.

Annual or biennial herbs; stigma brush-like; leaflets pectinate-pinnatifid.

20.

Poteridium.

Stamens of staminate flowers numerous, declined; pistils 2.

21.

Poterium.

Calyx-tube and fruit prickly; petals present, yellow.

22.

Agrimonia.

Seed erect, basal.

Style wholly deciduous (Colurieae).

23.

Waldsteinia.

Style persistent in whole or in part.

Calyx-tube hemispheric to turbinate, persistent; herbs (Dryadeae).

Calyx-lobes and petals 5; leaves pinnate.

Styles jointed, the upper part deciduous.

24.

Geum.

Styles not jointed, wholly persistent, mostly plumose.

25.

Sieversia.

Calyx-lobes and petals 8 or 9; leaves simple; styles plumose.

26.

Dryas.

Calyx-tube salver-shaped, the limb deciduous; the tube persistent, investing the achene;

shrubs or trees (Cercocarpeae).

27.

Cercocarpus.

2. Fruit of fleshy or nearly dry drupelets; ovary 2-ovuled (Rubeae).

Drupelets very pulpy.

28.

Rubus.

Drupelets nearly dry, enclosed by the calyx.

29.

Dalibarda.

** Carpels enclosed in the fleshy calyx-tube (Roseae).

30.

Rosa.