Despite the strong demand for chestnuts and chestnut products, the problems outlined above regarding harvesting and storage and the difficulties in obtaining a good, clean nut make chestnut production a difficult venture. Pecan: Carya illinoinensis, Juglandaceae Distribution and ecology Native of the rich bottom lands of the Mississippi Valley from Indiana and Illinois west to Kansas and Texas and at higher altitudes south into central Mexico, with local outliers to the north and east.