All of our species are natives of the Old World, escaped from cultivation. The corollas are various shades of red, pink, or white, sometimes variegated or spotted. The garden carnation is D. caryophyllus L., which does not escape. Dianthus chinensis L., Rainbow Pink was collected in Kent Co. in 1896, but it is unclear if it was an escape or a cultivated plant, as it was not noted by Cole (1901). It would run near D. armeria in the key; but it has a glabrous calyx subtended by more than 2 bracts, the basal leaves wither by flowering time, and the cauline leaves are broad. 

1. Flowers in a densely crowded inflorescence; bracts (including awns if present) at base of calyx mostly equaling or exceeding calyx tube.

2. Calyx pubescent.

D. armeria

2. Calyx (at least the tube) glabrous.

3. Largest cauline leaves ca. (1-) 1.5-2.5 (-3) cm broad, sheathing the stem for less than 3 times its diameter.

D. barbatus

3. Largest cauline leaves less than 0.5 cm broad, sheathing the stem for more than 3 times its diameter.

D. carthusianorum

1. Flowers solitary or if few, on evident pedicels; bracts at base of calyx ca. half as long as calyx tube, or shorter.

4. Stems (especially lower internodes) minutely puberulent; calyx ca. 12-14 (-18) mm long; lower leaves (on vegetative shoots) less than 2 cm long and minutely ciliate; margins of leaves thin; petals toothed but not lacerate.

D. deltoides

4. Stems glabrous; calyx ca. 16-23 mm (or more) long; lower leaves elongate, those of the dense basal tufts mostly at least 3 cm long and smooth to scabrous-margined; margins of leaves usually ± thickened; petals various.

5. Petals strongly lacerate, with hairs on the darker lower portion; plant ± glaucous.

D. plumarius

5. Petals merely toothed to entire, glabrous; plant green, not glaucous.

D. sylvestris