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..
Annual herbs, with alternate petioled exstipulate pinnately divided leaves. Flowers perfect, regular, white, pink or red, axillary, long-peduncled. Sepals 2-5, valvate, persistent. Petals the same number as the sepals, alternating with as many small glands, the nearly perigynous stamens twice as many, distinct. Filaments filiform; anthers 2-celled, the sacs longitudinally dehiscent. Carpels as many as the sepals and opposite them, I-ovuled, nearly distinct, the single slender style arising from the centre as in Geraniaceae, cleft above into as many stigmas as there are carpels; ovule ascending. Fruit very deeply 2-5-lobed, the carpels indehiscent, rough or tubercled. Embryo straight; endosperm none; cotyledons thick.
Two North American genera, the following, and Limnanthes, of the Pacific States, with about 9 species. The family was placed in the order Sapindales in our first edition, but is here brought into its more natural place in the Geraniales.