1613 COUDERC is a rootstock bred by Georges Couderc in 1881. Dr Richard Smart (2015, p628) describes 1613 Couderc as a complex hybrid between Solonis (V. riparia x V. rupestris x V. candicans) and Othello (V. labrusca x V. riparia x V. vinifera). It has low to moderate phylloxera resistance but moderate to high nematode resistance, he says, adding that it is well suited to fertile, sandy, loam soils, and is used mainly in California.
Dr Richard Smart in the Oxford Companion to Wine 4th edition ed. Jancis Robinson MW and Julia Harding MW (Oxford University Press, 2015, p628.