This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol2", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Herbs with alternate or opposite leaves, and axillary solitary or clustered perfect regular flowers. Stipules commonly present. Sepals 5 (rarely fewer), mostly persistent. Petals of the same number, hypogynous. Stamens as many as the sepals, or 2-3 times as many, distinct; anthers 2-celled, versatile. Ovary 1, usually 5-lobed and 5-celled; ovules 1 or 2 in each cavity. Fruit capsular. Embryo straight or curved; cotyledons flat or plicate.
About 12 genera and 470 species, natives of temperate regions, most abundant in South Africa.
Carpel-bodies turgid; carpel-tails (styles) glabrous within, merely recoiling at maturity; anthers usually 10 (or 5 in Geranium pusillum).
Carpel-bodies deciduous from the styles at maturity, each with 2 fibrous appendages near the
top; leaves divided.
Carpel-bodies permanently attached to the styles, unappendaged; leaves lobed, cleft or parted.
Carpel-bodies spindle-shaped; carpel-tails (styles) pubescent within, spirally coiled at maturity;