Scholz, H. & Böhling, N. 2000: Phragmites frutescens (Gramineae) re-visited. The discovery of an overlooked, woody grass in Greece, especially Crete. – Willdenowia 30: 251-261
key based on data from cited source
1Erect culms regularly with sterile side branches; mature culms woody; leaf blade tips pungent; spikelets 7-11 mm long; upper lemma 4-7 mm long; flowering in winter
1'Erect culms rarely with sterile side branches (in damaged or dwarfish plants); mature culms weak, enclosed by sheaths; leaf blade tips soft; spikelets 10-18 mm long; upper lemma (7-)9-12 mm long; flowering in summer and early autumn