20. Calligonum caput-medusae Schrenk, Enum. Pl. Nov. 1: 9. 1841.
头状沙拐枣 tou zhuang sha guai zao
Shrubs 1-3 m tall, 2-8 cm in diam., branched from base. Old branches light gray or yellow-gray, often longitudinally splitting; herbaceous branchlets of current year gray-green; joints 1-4 cm. Leaves linear, ca. 2 mm; ocrea united with leaf. Flowers 2 or 3, at leaf axil. Tepals reflexed in fruit, purple, ovate, 2-3 mm. Fruit yellow-green, red-brown, or red when young, becoming light yellow, yellow-brown, or red-brown, subglobose, 1-3 cm in diam. Achenes ellipsoid, coiled, prominently ribbed; bristles dense, 2 rows per rib, slightly flat at base, separate or somewhat united, 2- or 3-forked below middle, then repeatedly 2- or 3-forked, spiniform, stiff; apically spreading. Fl. Apr-May, fr. May-Jun. 2n = 36*.
Sand dunes, steppes; 300-900 m. Gansu, Ningxia, Xinjiang [Kazakhstan, Turkmenistan].