Nap-at-noon, sleepy dick

Plants (10–)20–30(–40) cm; bulbs renewed each year, 1–2 × 1–2.5(–3.5) cm; bulblets numerous. Leaves 4–6(–9); blade with white adaxial stripe, 20–30 cm × 3–5(–8) mm. Scape 1–3 dm. Inflorescences corymbose, (4–)8–20-flowered, flat-topped; bracts to 4 cm. Flowers erect; perianth opening flat or bowl-shaped in sun, closing at night, remaining closed on cloudy days; tepals white with wide green abaxial stripe, lanceolate to oblong-lanceolate, 15–22(–30) × 7–8 mm; stamens: outer 5–7 × 2–3 mm, inner 6–8 × 2–3 mm; filaments simple, flattened; anthers 2–4 mm; ovary ovoid to obovoid, strongly 6-angled, 5–6 mm; style 3–4 mm; lower pedicels 2–6 cm. Capsules oblong-ovoid. 2n = 18, 20, 27, 28, 35, 36, 42, 44, 45, 54, 72, 90, 108.

Flowering spring. Roadsides, open forests, waste places, dumps; 0--1500 m; introduced; B.C., N.B., Nfld. and Labr.(Nfld.), N.S., Ont., Que.; Ala., Ark., Conn., Del., D.C., Ga., Idaho, Ill., Ind., Iowa, Kans., Ky., La., Maine, Md., Mass., Mich., Miss., Mo., Nebr., N.H., N.J., N.Y., N.C., Ohio, Okla., Oreg., Pa., R.I., S.C., S.Dak., Tenn., Tex., Utah, Vt., Va., Wash., W.Va., Wis.; Europe; n Africa; Asia; Middle East; expected elsewhere.

Planted as a garden ornamental, Ornithogalum umbellatum produces many offsetting bulblets that are transported in soil and can become rampant weeds. Adding to the vegetative vigor of this species may be its aneuploid-polyploid karyology (T. W. J. Gadella and L. van Raamsdonk 1981; L. van Raamsdonk 1984). The flowers are noteworthy for their regularity in opening just before noon and closing again before sunset.

Two digitalis-like glycosides, convallatoxin and convalloside, poisonous to humans and livestock, are found throughout the plant, but are concentrated in the bulbs and the flowers (W. H. Blackwell 1990; K. F. Lampe and M. A. McCann 1985; D. G. Spoerke Jr. and S. C. Smolinske 1990).