Clone of Prunus mahaleb, found and selected by the INRA Experimental Station, Bordeaux, France. Trees in the nursery are uniform and more vigorous than the cherryseedling (P. avium), with intermediate growth habit. Good grafting compatibility and good performance in the nursery (rapid growth, easy to graft and successful grafting). Late summer budding (T and chip), winter grafting, and spring budding (T and chip) with growing buds lead to high taking percentages. Plants grafted on this rootstock are 20% more vigorous than those grafted on CAB 6P and 10- 20% less than those grafted on cherry seedlings, depending on soil fertility and orchard practices. Deep root system with good anchorage, composed of vigorous, long, hairy roots which penetrate fairly deeply in the ground. Suitable for poor, permeable and calcareous soils. This is the best rootstock for semi-arid areas characterised by high evaporative demand and low water availability for irrigation. It is sensitive to Phytophtora cactorum, Armillaria mellea, Rosellinia necatrix and Verticillium dahliae, tolerant to bacterial canker (Pseudomonas syringae) and shows low sensitivity to crown gall (Agrobacterium tumefaciens) Tolerance to nematodes is medium. Plants grafted on SL 64 generally crop later than those grafted on ‘CAB 6P’. Yield efficiency is high 4- 5 years after planting. It is suitable for specialised cherry orchards of medium-low (300-400 trees/ha) or medium-high (up to 700 trees/ha) densities.