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..
Erect or ascending herbs, with scaly or bulbiferous rootstocks, or fibrous roots, entire lobed or divided leaves, and racemose or corymbose white or purple flowers. Stamens 6, rarely 4. Siliques elongated, flat, generally erect; elastically dehiscent at maturity; valves nerveless or faintly nerved. Stipe none. Seeds in 1 row in each cell, compressed, margin-less; cotyledons accumbent, equal or unequal. [Greek, heart-strengthening, a name for some cress supposed to have that quality.]
A genus of about 125 species, natives of the temperate regions of both hemispheres. Type species: Cardamine pratensis L.
* Leaves pinnately divided, or some of them of but a single terminal segment.
Flowers 6"-9" broad, white or purplish; perennial.
Flowers 1"~4" broad, white.
Leaf-segments numerous, small, the terminal one 2"-10" wide, narrowed, rounded or subcor-
date at the base; annuals or biennials.
Leaves nearly all basal, pubescent.
Stem leafy; leaves glabrous or very nearly so.
Segments of basal leaves 2"-12" wide; plant 8'-3° tall.
Segments of basal leaves 1/2"-1 1/2" wide; plant 6'-12' tall.
Flowers 1"-1 1/2" wide; plant of dry rocky situations.
Leaf-segments few, large, the terminal one 1' - 2' wide, deeply cordate; perennial.
** Leaves entire, toothed, or rarely with 1 or 2 lateral segments; perennials.
Erect or decumbent; leaves more or less toothed or lobed.
Flowers purple; stem erect, from a tuberous base.
Stem erect from a tuberous base.
Stem decumbent, stoloniferous; roots fibrous.