May Lily

Maianthemum dilatatum (A. W. Wood) A. Nelson & J. F. Macbride (Bot. Gaz. 61: 30. 1916), from Japan, Mongolia, E Russia, and NW North America, probably occurs in China. In Russia and Japan, M. dilatatum is sympatric with M. bifolium and, in Japan, there occur intermediate forms which may have derived from hybridization between the two species (Kawano, pers. obs.). Such plants in the Russian Far East have been called M. intermedium Voroschilov (Izv. Glavn. Bot. Sada RSFSR 38, 50. 1960) and may also occur in China.

Plants 8--20(--25) cm tall. Rhizome sometimes forked, to 20 cm × 1--2 mm. Stem sometimes scattered papillose-pubescent. Basal leaf withered at anthesis; petiole to 10 cm. Cauline leaves usually 2, borne distally to apically on stem; petiole 1--2 cm, often papillose-pubescent; leaf blade deltoid-ovate, 3--8(--10) × 1--5(--9) cm, abaxial veins puberulent, base cordate, margin minutely denticulate-papillose or puberulent. Raceme erect, 3--5 cm, 10--25-flowered; rachis papillose-pubescent; bracts minute. Flowers solitary or paired; pedicel ca. 5 mm, slender, articulate apically. Perianth white; segments oblong, 2--2.5 × 1.5--1.8 mm. Stamens 1.6--2.1 mm. Style ca. 1 mm. Berries red at maturity, 3--6 mm in diam. Seeds with yellow testa. Fl. May--Jul, fr. Aug--Sep. 2 n = 28, 30, 36, 42, 54, 88.

Gansu, Hebei, Heilongjiang, Jilin, Liaoning, Nei Mongol, Qinghai, Shaanxi, Shanxi, Sichuan, N Xinjiang [Japan, Korea, Mongolia, Russia; Europe, North America].

Forests, thickets, moist places, hillsides along streams; 500--2700 m.

Convallaria bifolia Linnaeus, Sp. Pl. 1: 316. 1753; Smilacina bifolia (Linnaeus) Desfontaines.