The simple, alternate leaves of Nicotiana glauca ascend on long petioles. They are ovate in shape, tapering or square at the asymmetrical bases and tapering to their acutely pointed tips. The blades are glaucous, smooth and leathery to fleshy, the margins entire. Leaf dimensions are 20 cm long and 12 cm wide.

The specific name, glauca, is a Latin word meaning blue-grey or emerald green.

The plant is an evergreen, in spite of its adaptation to dry areas (Curtis-Scott, et al, 2020; Jeff Ollerton, et al, 2012: Pollination ecology of an invasive tree tobacco Nicotiana glauca: Comparisons across native and non-native ranges. Journal of Pollination Ecology, 9(12), pp 85-95; Shearing and Van Heerden, 2008; Coates Palgrave, 2002; Van Wyk and Van Wyk, 1997).