Field Chickweed, Field Mouse-ear: Cerastium arvense ssp. strictum (Synonyms: Cerastium arvense ssp. maximum, Cerastium viride) - Perennial. Petals usually at least 1.5 times longer than the calyx. Flower bracts membranous. Leaf axils usually with axillary bundles of leaves. Cymes 5-9 flowered.
Alpine Cerastium, Alpine Chickweed, Bering Chickweed, Bering Sea Chickweed: Cerastium beeringianum (Synonyms: Cerastium alpinum var. beeringianum, Cerastium alpinum var. capillare, Cerastium beringianum, Cerastium beeringianum ssp. beeringianum, Cerastium beeringianum ssp. earli , Cerastium beeringianum var. capillare, Cerastium beeringianum var. glabratum, Cerastium beeringianum var. grandiflorum, Cerastium buffumiae, Cerastium earlei, Cerastium fischerianum var. beeringianum, Cerastium pilosum, Cerastium pulchellum, Cerastium scammamiae, Cerastium variabile, Cerastium vulgatum var. beeringianum) - Perennial. Petals usually at least 1.5 times longer than the calyx. Flower bracts rarely membranous. Leaf axils usually without axillary bundles of leaves. Cymes 1-5 flowered.
Dry Chickweed, Forked Mouse-ear Chickweed: Cerastium dichotomum (Synonyms: Cerastium siculum) -
Doubtful Chickweed: Cerastium dubium -
Big Chickweed, Common Mouse-ear, Mouse-ear Chickweed: Cerastium fontanum ssp. vulgare (Synonyms: C. holosteoides, Cerastium vulgatum) - Biennial. Petals shorter than to equal to the sepals. Plants short hairy, not glandular. Pedicels longer than the calyx.
Sticky Cerastium, Sticky Chickweed, Sticky Mouse-ear: Cerastium glomeratum (Synonyms: Cerastium acutatum, Cerastium fulvum, Cerastium glomeratum var. apetalum, Cerastium glomeratum var. glomeratum, Cerastium viscosum, Cerastium viscosum var. viscosum) - Annual. Petals about equal to the sepals. Plants glandular-hairy. Pedicels shorter than the calyx.
Nodding Chickweed: Cerastium nutans (Synonyms: Cerastium brachypodum, Cerastium nutans var. nutans) - Annual. Petals equal to or longer than the sepals. Plants glandular-hairy.
European Chickweed, Sticky Mouse Ear Chickweed: Cerastium pumilum (Synonyms: Cerastium glutinosum, Cerastium pumilum ssp. glutinosum) -
Dry Chickweed: Cerastium siculum - Annual. Petals about equal in length to the sepals. Pedicels shorter than the sepals. Leaves spatulate to obovate.
Snow-in-Summer: Cerastium tomentosum - Annual garden escapee. Petals at least 1.5 tims longer than the calyx. Herbage white tomentose throughout (unique in this group).