I've always thought the species Lychnis flos-cuculi to be a "sloppy" plant....too tall for it's own good and without much garden merit.  Imagine how ecstatic I was to find this dwarf form.  Seemingly suffering from an identity crisis,  the same plant is slowly making it's rounds under several different names ie: Lychnis flos-cuculi nana,  mini,  minimus,  dwarf form etc etc.  But they all seem to be the same plant,  a tight little compact form of Lychnis flos-cuculi.  From a ground hugging little rosette of greyish-green,  glossy foliage,  a 2"-6" flower stem emerges in early to mid Summer and long lasting,  finely cut,  pink flowers burst forth in all directions.

The straight species, Lychnis flos-cuculi is native to moist,  open meadows in Europe,  but has naturalized itself as an escapee from cultivation through much of New England and the Northeastern US. Although I've never grown them,  there are a few other reported cultivars,  a white form,  L. c. 'Alba',   L. c. 'Roseoplena' a double pink,  and L. c. 'Alboplena',  a double white.

There's an excellent closeup of the flowers at: http://www.bioimages.org.uk/HTML/P141261.HTM

I'd previously surmised that the reason for many plants in Caryophyllaceae,  primarily Dianthus, being referred to as "Pinks" was because so many of them were pink. A logical conclusion huh?  But nooooooooooo,  the real reason is that the ragged edge of many of the flowers look "pinked",  you know,  cut with "pinking shears".  Most plants in the Caryophyllaceae are short lived perennials. Luckily this is a form that comes true from seed,  and plenty of seed you will get.

It's sort of tricky to propagate from division. Although it does provide several new divisions,  the roots are so fine and the new plants are so tight against the stem and base of the parent plant, that they're difficult to remove with a healthy portion of roots.

Taxonomic Hierarchy
Kingdom - Plantae - Plants
Subkingdom - Tracheobionta - Vascular plants
Superdivision -  Spermatophyta - Seed plants
Division - Magnoliophyta - Flowering plants
Class - Magnoliopsida - Dicotyledons
Subclass - Caryophyllidae
Order - Caryophyllales
Family - Caryophyllaceae
Genus - Lychnis
Species - flos cuculi
Cultivar name - nana,  mini, minimus, dwarf form
Common name - genus -  "Campion"
Common name - species - "Dwarf Ragged Robin", "Cuckoo Flower"
Synonyms - Coronaria flos cuculi,  Silene flos cuculi
Native range - Europe,  but naturalized in many areas in the US
USDA Hardiness Zone - 4, most likely 3
Light preference -  Open bright shade to full sun
Soil fertility preference -    Average to rich
Soil pH preference - neutral to slightly acidic
Soil moisture preference - Mesic to Hydric
Bloom time -  Early-mid Summer
Bloom color - Pink
Fragrance - No
Foliage -  Grey - green
Spread - 3" - 6"
Height - 3" - 6"
Deer palatability - Seems deerproof
Landscape uses - Front of any border, Rock Garden,  Trough Garden
Related species - Lychnis coronaria,  Lychnis flos jovis
Medicinal uses -  None found