Soy varies in growth and habit. The height of the plant varies from less than 0.2 to 2.0 mt.
The pods, stems, and leaves are covered with fine brown or gray hairs. Theleavesaretrifoliolate, having three to four leafletsper leaf, and the leaflets are 6–15 cm long and 2–7 cm broad. The leaves fall before the seeds are mature. The inconspicuous, self-fertile flowers are borne in the axil of the leaf and are white, pink or purple.
The fruit is a hairy pod that grows in clusters of three to five, each pod is 3–8 cm long and usually contains two to four seeds 5–11 mm in diameter.
Soybeans occur in various sizes, and in manyhullor seed coat colors, including black, brown, blue, yellow, green and mottled.