Cuckooflower - how does it produce seeds?

Hello, take a look at this article, it might help you. Report back if you still need assistance: http://content.ces.ncsu.edu/plant-propagation-by-leaf-cane-and-root-cuttings-instructions-for-the-home-gardener/

when I cut leafs they wouldn't grow back. At some stage of growth a lot of stems has split over 2

About Cuckoo Flower: Cuckoo Flower, so named because it blooms when the cuckoos begin to call, can be found in marshes, moist woodland, or at water’s edge. It provides a source of nectar for the orange-tip butterfly, which brings assurance of coming spring in the United Kingdom and Ireland. In former times this wildflower was considered the special property of the fairies, and thought to bring misfortune if used for bouquets. Its genus name, Cardamine, comes from the Greek “kardamon,” the word for an unconnected plant used as a spice; this is probably derived from the Cuckoo Flower’s peppery flavored leaves.
Cuckoo Flower Germination: In late fall or spring, direct sow just below the surface of the soil and water lightly. This plant prefers moist but well-drained soil, and tolerates clay or sand.
Growing Cuckoo Flower Seeds: Seedlings should be watered regularly, and mature plants may need occasional watering since they prefer moist soil. After several years of growth, the plants can be divided in spring or fall to produce new and healthier plants. Cuckoo Flower also reseeds itself, and volunteer plants may grow in the surrounding area.
Harvesting Cuckoo Flower: For fresh flowers, cut the stems long and place them in water immediately. The leaves and flowers of this plant are edible and nutritious when harvested young. Having a sharp, cress-like flavor, they are generally used in salads or as a garnish.
Saving Cuckoo Flower Seeds: The long, narrow seed pods that form will explode when fully ripe. Because of this, they must be watched carefully to avoid loss. As soon as the seed pods begin to turn color or contain mature seed, remove them and spread them out to dry; a cover of some kind will be necessary, since they still explode as they dry. Separate the seed from the dried pods. Store the seed in a cool, dry place.
Detailed Cuckoo Flower Info: Origin: Europe, US Native Other Common Names: Lady's Smock, American Cuckoo-flower, Mayflower, Meadow Cress, Milkmaid Duration: Perennial Bloom Time: Spring-Early Summer Height: 9-18 inches Spacing: 12-15 inches Light: Full Sun to Part Shade Soil Moisture: Medium USDA Zone: 3a-9b Seeds Per Oz: 4,000 Produces divided foliage with round leaflets, and ½” pale pink or white four-petaled flowers.

Might even be that your soil is poor, lacking nutrients.

I know a cuckooflower aren't succulents, but there is also this tutorial that shows how to grow plants from their leaves: http://needlesandleaves.net/blog/2013/5/31/propagating-leggy-succulents

Apart from this, I wouldn't know how to approach this issue.

ok, epic fail after 2 months, I failed. It stopped growth after week and these plants were mature, some of them dried I don't know why. I discovered that this plant like to be in totally flooded land - they need it because one day without water and they are practically dead. I tried to add a little fertilizer but then plants died. They are very delicate.
2 months of growth and nothing happens even not produced flowers not mentioning seeds.
I think that problem was with my seeds from shop - they were male or female or sprayed with something so that they cannot reproduce.
I don't know even when I can buy appropriate for reproducing seeds.