Key to subspecies of Psammogeton canescens (DC ex Boiss.)
Vatke
1. Main axis elongate, lateral branches shorter than the main axis
———————————————————————————————————–P. canescens subsp. canescens
– Main axis and lateral branches arising from the base of axis
———————- 2
2. Branches slightly shorter, never overtopping the main axis; peduncle
up to 3 cm long
————————–P. canescens subsp. buschirensis
– Branches always overtopping the main axis; peduncle up to 8 cm long
—————————————————————————————————P. canescens subsp. cabulicus