直茎红景天 zhi jing hong jing tian

Sedum recticaule (Borissova) Wendelbo.

Main root thick, woody. Caudex branched, 3-6 cm in diam., woody, apically leafy; branches ca. 1.5 cm in diam. Caudex leaves brown, scalelike, triangular, ca. 1 × 1 mm, apex obtuse. Flowering stems numerous, erect, 8-15 cm × 1.5-2 mm, slightly sulcate; persistent old flowering stems present. Stem leaves alternate, erect or divergent, sessile, yellowish green, elliptic to elliptic-oblong, 8-10 × 2-3 mm, margin coarsely dentate, apex subacute. Inflorescences corymbiform-capitate, compact, 1.5-2 cm in diam., many flowered, bracteate. Flowers shortly pedicellate, unisexual, unequally 4-merous, small. Sepals red, elliptic, ca. 2 mm, apex obtuse. Petals yellow, oblong-elliptic, ca. 4 mm, apex obtuse. Stamens 8, longer than petals; filaments yellow; anthers globose. Nectar scales subquadrangular, apex entire. Carpels erect. Stigma capitate. Follicles apically shortly beaked. Seeds brown, oblong, ca. 2 mm. Fl. Jun-Aug, fr. Jul-Sep.

Rock crevices on mountain slopes; 3800-4600 m. Xinjiang (Tian Shan) [Kazakhstan; SW Asia (Iran)].

Typical Rhodiola recticaulis has flowering stems to 5 mm thick and globose inflorescences. One of the present authors (Ohba) believes that the Chinese plants described here need further invistigation, as they may prove to be a different species.