Description from Flora of China
Demidovia tetragonioides Pallas, Enum. Hort. Demidof, 150. 1781; Tetragonia expansa Murray.
Herbs annual, erect when young, becoming decumbent, 40-60 cm tall. Stems with densely placed bladder cells when young. Petiole 5-30 mm, thick; leaf blade rhomboid-ovate or deltoid-ovate, 0.4-10 × 2.5-8 cm. Pedicel to 2 mm. Flowers 1-3. Perigone tube 2-3 mm; lobes mostly 4, inside bright yellow to yellowish green. Stamens 10-13. Fruit turbinate, ca. 5 mm, 4- or 5-corniculate. Seeds as many as locules. Fl. and fr. Aug-Oct. 2n = 16*
This species is used medicinally and is cultivated as a vegetable worldwide.
Sandy shores, also cultivated. Fujian, Guangdong, Jiangsu, Taiwan, Yunnan, Zhejiang [Africa, E Asia, Australia, South America].