SAXIFRAGACEAE
General description:- Herbs, mostly perennial.
Flowers:- 4- or 5-merous, usually in cymes (rarely solitary or in racemes). Petals usually 4 or 5; sometimes absent. Stamens twice as many as the sepals, or rarely equal in number or fewer. Carpels 2; united below but usually divergent above; styles free. Ovary superior, semi-inferior or almost inferior.
Fruit:- A capsule. Seeds numerous.
Key features:-
1) Leaves not more than 6 cm wide.
2) Hypanthium united with lower part of ovary, or absent.
Sect. COTYLEA
General description:- Evergreen perennials with underground rhizome or stock.
Leaves:- Alternate, mostly basal, long-petiolate, entire to crenate, dentate or slightly lobed. Flowering stem leafy.
Flowers:- In a panicle. Sepals erect or patent; petals white, usually with red or yellow spots. Ovary superior.
Sect. CYMBALARIA
General description:- Usually annuals.
Stems:- Diffuse, ascending, leafy.
Leaves:- Mostly alternate, palmately lobed to entire, long-petiolate.
Flowers:- Petals white, yellow or orange. Ovary superior or very nearly so.
Sect. SAXIFRAGA
General description:- Usually perennial; habit varied, but usually with numerous leafy shoots, forming a mat or cushion.
Leaves:- Alternate, fairly soft, often lobed or crenate, without calcareous incrustation.
Flowers:- Petals usually white, more rarely pale or dull yellow, pink or red. Ovary semi-inferior to inferior.
Subsect Saxifraga
General description:- Always perennial.
Leaves:- Most of the leaves lobed, or boldly crenate.
Series Saxifraga
General description:- Evergreen or summer-dormant, with bulbils in the axils of the basal leaves, rarely also of the upper leaves.
Flowers:- Petals white, rarely tinged with pink.