Diagnostic key for Achyranthes taxa occurring in Saudi Arabia

1. Main stem usually glabrous or glabrescent; abaxial surface of leaves villous, whitish........................................ Achyranthes sicula

1. Main stem pubescent; abaxial surface of leaves glabrous or pubescent (not villous), green.............................................................2

2. Leaf blades rounded to obovate-orbiculate, obtuse to slightly retuse (sometimes abruptly apiculate); tepals 3−4 mm long.............. ........................................................................................................................................................... Achyranthes aspera var. aspera

2. Leaf blades ovate, acuminate; tepals 6−7 mm long .................................................................... Achyranthes aspera var. pubescens