Water absorption by mucilaginous achenes of artemisia monosperma: Floating and germination as affected by salt concentrations

Artemisia monosperma is a dominant perennial desert shrub occurring in active sand dunes and stabilized sand fields. A cyanobacterial crust develops on stabilized sand and, as a result, runoff water may occur after rains. The mucilaginous achenes may float on the runoff water and disperse into depressions or cracks. In these experiments, almost half of the achenes remained afloat on distilled water for 3 days and on different concentrations of salt solutions, more achenes remained afloat for longer. High concentrations of salt inhibit germination. NO,” may influence achene germination on cyanobacterial sand crust. Mucilaginous achenes absorb water within about 60 min, and after 120 min reach their water capacity. The achenes from which the mucilage has been removed can float for a longer period and germinate earlier than intact ones. Seedlings that developed from achenes with mucilage had greater vigor than those without. The ecological significances of mucilaginous achenes is discussed.