The small, simple leaves of Selago flanaganii are alternate, often in clusters on small side-branchlets and higher up densely present on the woody stems. Secondary leaves are smaller. The narrowly elliptic to linear green blades are sometimes hairy, their margins entire or having up to three teeth in the upper halves. In picture the ascending leaves curve in.
Leaf dimensions are 4 mm to 12 mm long and 1 mm to 3 mm wide (Pooley, 1998; Trauseld, 1969; iNaturalist; https://www.worldfloraonline.org).