1Tomentum on twigs dense, relatively long-persistent, consisting of patent hairs 0.2-0.6 mm long
1'Tomentum on twigs dense to open (twigs almost glabrous), consisting of ± adpressed hairs or very short patent hairs less than 0.1 mm long
2Abaxial surface of calyx sparsely hirsute or strigose-hirsute throughout. Upper surface of leaves hirsute along midrib and nerves with tomentum ± persistent; intervenium on both surfaces bearing an evanescent tomentum
2'Abaxial surface of calyx glabrous or at most very sparsely strigose near base only. Upper surface of leaves glabrous or with few usually caducous hairs on midrib and nerves; intervenium on both surfaces glabrous
3Ovules 2 per cell
3'Ovules 4 per cell