Description from Flora of China
Lotus corniculatus Linnaeus var. tenuifolius Linnaeus; L. corniculatus subsp. tenuis (Waldstein & Kitaibel ex Willdenow) Briquet; L. glaber Miller, nom. utique rej.; L. tenuifolius (Linnaeus) Reichenbach.
Herbs, perennial, 20-100 cm, with a taproot, glabrescent or sparsely puberulent with short appressed hairs. Stem slender, erect or ascending. Leaflets 5, obovate-oblanceolate or oblanceolate to linear, 4-18 × 1-4 mm, basal 2 shorter; terminal leaflet of a leaf 1.5-3 × as long as leaf rachis. Umbels (1 or)2-5-flowered; peduncle 3-12 cm, slender; bracts 1-3, 1.5-2 × as long as calyx. Flowers 8-10.5(-11) mm. Calyx 4-6 mm; teeth shorter than tube, narrow part of 2 upper calyx teeth less than half their length. Corolla yellow. Ovary linear; ovules numerous; style 4-5.5 mm. Legume straight, cylindric, 9-25 × 1.2-2.5 mm. Seeds light brown, globose, 1.4-1.6 mm, smooth. Fl. May-Aug, fr. Jul-Sep.
Whether this is a native or introduced species in China needs verification.
Saline, poorly drained grasslands of lake or swamp shores. NW China, Tianjin [Afghanistan, Kazakhstan, Kyrgyzstan, Mongolia, Pakistan, Russia (European part, Siberia), Tajikistan, Turkmenistan, Uzbekistan; N Africa, SW Asia, Europe; introduced in North America, Pacific islands (New Zealand), and South America (Argentina)].