四棱豆是多年生宿根性藤本植物,茎圆柱形,具不明显的纵条纹;叶互生,三出复叶,全缘,顶端急尖,叶片长8—13厘米,宽5—10厘米,叶柄基部具小托叶;花为腋生的总状花序,花序长15厘米,每序有小花10—15朵,外面白色,里面蓝色;豆荚长约10—15厘米,每个豆荚有种子15—20粒,种子黄色或黑色,每粒种子重0.3—0.4克。四棱豆边缘带皱,有四条棱故称四棱豆;形状如翼,又称 Four-sided beans are perennial perennial rattan, stems cylindrical, with no obvious vertical stripes; leaves alternate, three out of the compound leaves, entire, top acute, leaves 8-13 cm long, 5-10 cm wide, petiole Basal with small stipules; flowers axillary racemes, inflorescences 15 cm long, each order florets 10-15, outside white, inside blue; pods about 10-15 cm, each pod has seeds 15- 20 seeds, yellow or black seeds, each 0.3-0.4 grams of seeds weight. Four-edged beans with wrinkles on the edge, there are four edges so called beans; shape wings, also known as