2. Cerastium brachypetalum Pers. (gray mouse-ear chickweed)

C. brachypetalum ssp. tauricum (Spreng.) Murb.

C. brachypetalum f. glandulosum W.D.J. Koch.

Map 1451, Pl. 340 g

Plants annual. Stems 5–35 cm long, erect, usually branched toward the tip, moderately to densely pubescent with long, silvery, nonglandular hairs, these sometimes mixed with or replaced by stalked glands toward the tip. Leaves sessile, lacking axillary clusters of leaves. Leaf blades 0.5–2.5 cm long, spatulate (some basal leaves) or elliptic to ovate, angled to a bluntly or sharply pointed tip. Flowers in open panicles, the stalks 0.6–1.6(–2.5) cm long, these (1–)2–3(–6) times as long as the sepals, erect or spreading, at fruiting sometimes appearing hooked near the tip, densely pubescent with glandular hairs, the bracts with herbaceous, green margins. Sepals 5, 3–5 mm long, lanceolate, green, angled to a bluntly or sharply pointed tip, densely pubescent with nonglandular and sometimes also glandular hairs, these extending past and somewhat obscuring the sepal tips. Petals 5, 2.0–3.5 mm long, about 2/3–3/4 as long as the sepals, shallowly 2-lobed at the tip, the veins usually not apparent. Stamens 10. Styles 5. Fruits 6.0–8.5 mm long, about 1.5 times as long as the sepals, slightly curved. Seeds 0.4–0.5 mm wide, the surface tuberculate, light brown. 2n=88, 90. April–May.

Introduced, scattered in the western half of the Ozark Division, uncommon and sporadic farther north and east (native of Europe; introduced in the eastern U.S. west to Kansas and Texas, also Idaho and Oregon). Glades, ledges of bluffs, upland prairies, and margins of sinkhole ponds; also pastures, roadsides, and open, disturbed areas.

Cerastium brachypetalum is the largest and usually the most diffusely branched of the introduced annual chickweeds. Although most of the Missouri specimens are covered with distinctive long, silvery, nonglandular hairs, the stems, flower stalks, and sepals of some plants are mostly stipitate-glandular. Steyermark (1963) called such plants f. glandulosum, but some European botanists have used this as one of the characters used in distinguishing among as many as eight subspecies (Sell and Whitehead, 1993). The present treatment follows that of Morton (2005a) in not formally recognizing this distinction.