Composed of, or arranged in, sets of four. (adjective)
Examples of word quaternate
I had the good fortune to find two plants of clover, bearing one quinate and several quaternate leaves, on an excursion in the neighborhood of Loosdrecht in Holland.
When a plant bearing a quaternate leaf is thus transplanted however, it rarely repeats the  anomaly.
This number in one summer amounted to 46 quaternate and 16 quinate leaves, and it was evident that I had secured an instance of the rare "five-leaved" race which I am about to describe.
Often all these deviations may be seen among the seedlings of one lot, and then it is obvious that together they constitute a scale of cleavages, the ternate and quaternate whorls being only cases where the cleaving has reached its greatest development.
The common laburnum has a variety which often produces quaternate and quinate leaves, and in strawberries I have also seen instances of this abnormality.