3b. Leaves whorled; flowers white (1-5 dm. high; leaves linear; summer) =Spurrey, Spergula arvensis.= 4a. Leaves subulate or thread-like --5. 4b. Leaves linear to ovate --7. 5a. Leaves opposite (1 dm. high or less; flowers white, summer) =Pearlwort, Sagina procumbens.= 5b. Leaves fascicled in the axils --6. 6a. Styles 4 or 5 (1 dm. high; terminal white flowers 5 mm. wide, in summer) =Pearlwort, Sagina nodosa.= 6b. Styles 3 (1-4 dm. high; flowers white, nearly 1 cm. wide, summer) =Stitchwort, Arenaria stricta.= 7a. Petals entire (3 dm. high or less; flowers white, in summer) (Stitchwort) --8. 7b. Petals notched or 2-cleft at the end, or none --11. 8a. Principal leaves 1 cm. long or less --9. 8b. Principal leaves 1.5 cm. long or more --10. 9a. Petals half as long as the sepals =Stitchwort, Arenaria leptoclados.= 9b. Petals almost as long as the sepals =Stitchwort, Arenaria serpyllifolia.= 10a. Leaves oblong-oval, obtuse. =Stitchwort, Arenaria lateriflora.= 10b. Leaves lanceolate, acute. =Stitchwort, Arenaria macrophylla.= 11a. Capsule splitting by valves at maturity; styles usually 3 (Chickweed) --12. 11b. Capsule opening by terminal teeth at maturity; styles usually 5 (tufted or matted plants, 1-5 dm. high; flowers white, in spring and summer) (Mouse-ear Chickweed) --18. 12a. Petals distinctly shorter than the sepals, or none --13. 12b. Petals as long as the sepals, or longer --15. 13a. Leaves ovate (1-3 dm. high; flowers white, all summer) =Chickweed, Stellaria media.= 13b. Leaves lanceolate to oblong (in water or wet places, 1-4 dm. high; flowers white, in summer) --14. 14a. Flowers in a leafy terminal branching cluster =Chickweed, Stellaria borealis.= 14b. Flowers in a lateral cluster with minute bracts =Chickweed, Stellaria uliginosa.= 15a. Flowers in clusters with leaf-like bracts, or axillary and solitary (in water or wet places; 1-3 dm. high; flowers white, summer) =Chickweed, Stellaria crassifolia.= 15b. Flowers in clusters with scale-like bracts --16. 16a. Leaves distinctly linear; cymes lateral; a common species in marshes (2-5 dm. high; flowers white, early summer) =Chickweed, Stellaria longifolia.= 16b. Leaves distinctly broadest near the base; flower-cluster terminal --17.