Muir is an extremely heat tolerant variety and was the slowest to bolt in our summer trials. Technically a Batavian type, the light green, extra-wavy leaves form dense heads at a small size and can be harvested as a mini or left to bulk up into large, heavy, full-size heads. The leaves are crisp and have excellent flavor. Suitable for hydroponic systems. Utility Patent granted. High resistance to downy mildew races EU 16–26, 28, 32; US 5–9, Nasonovia nibisnigri aphid, and tomato bushy stunt virus (lettuce dieback complex); intermediate resistance to lettuce mosaic virus. MT0-30. USDA Certified Organic. Avg. 1,100 seeds/oz. Packet: 250 seeds.