The first true leaves develop as a pair of single blades.Subsequent to this first pair, mature nodes form compound leaves with three blades. Mature trifoliolate leaves, having three to four leaflets per leaf, are often between 6–15 cm long and 2–7 cm broad. Under ideal conditions, stem growth continues, producing new nodes every four days. Before flowering, roots can grow 1.9 cm (0.75 inch) per day. If rhizobia are present, root nodulation begins by the time the third node appears. Nodulation typically continues for 8 weeks before the symbiotic infection process stabilizes.The final characteristics of a soybean plant are variable, with factors such as genetics, soil quality, and climate affecting its form; however, fully mature soybean plants are generally between 51–127 cm in height and have rooting depths between 76–152 cm .