nea.=

18a. Petals distinctly longer than the sepals --19.

18b. Petals as long as the sepals, or shorter than them --21.

19a. Flowers much less than 1 cm. wide
=Mouse-ear Chickweed, Cerastium nutans.=

19b. Flowers more than 1 cm. wide --20.

20a. Stem-leaves linear or narrowly lanceolate
=Mouse-ear Chickweed, Cerastium arvense.=

20b. Stem-leaves oblong
=Mouse-ear Chickweed, Cerastium arvense var. oblongifolium.=

21a. Bracts green; pedicels short and inflorescence crowded
=Mouse-ear Chickweed, Cerastium viscosum.=

21b. Bracts with transparent white margins; pedicels longer than the
calyx and inflorescence open
=Mouse-ear Chickweed, Cerastium vulgatum.=

22a. Styles 5 --23.

22b. Styles 3 (3-10 dm. high; flowers in summer) --25.

22c. Styles 2 --29.

23a. Calyx-teeth much longer than the calyx-tube (erect, 4-10 dm. high;
flowers large, red, late summer)
=Corn Cockle, Agrostemma githago.=

23b. Calyx-teeth shorter than the calyx-tube (4-10 dm. high; flowers in
summer) --24.

24a. Flowers crimson =Mullein Pink, Lychnis coronaria.=

24b. Flowers white or pink =White Campion, Lychnis alba.=

25a. Flowers night-blooming, always wilted during the day
=Catchfly, Silene noctiflora.=

25b. Flowers open during the day --26.

26a. Flowers 6 mm. wide or less, white or pink
=Catchfly, Silene antirrhina.=

26b. Flowers 1-2 cm. wide, white to pink or purple --27.

26c. Flowers 2 cm. wide or more, crimson
=Fire Pink, Silene virginica.=

27a. Principal leaves in whorls of 4
=Starry Campion, Silene stellata.=

27b. Leaves opposite --28.

28a. Calyx globular, much inflated or bladder-like
=Bladder Campion, Silene latifolia.=

28b. Calyx club-shape, not inflated
=Sweet William Catchfly, Silene armeria.=

29a. Leaves linear or narrowly lanceolate, 5 mm. wide or less (flowers
pink or white, in summer) --30.

29b. Leaves lanceolate or ovate (flowers pink, white, or red, in summer)
--32.

30a. F