Saturday, September 10, 2016

Typha Latifolia Begins its Invasion

Only one of the original 7 bulrushes has thrived, although I don't think it's going to flower this year. In fact, although these plants are perennial, they actually seem to behave more like biennials, flowering in their 2nd year. And when they do flower, according to Motivans & Apfelbaum, the seeds have a very high germination rate. But they also reproduce vegetatively, from rhizomes. As you can see in the photo, the original plant to the right has grown a new ramet, (for which terminology see Grace & Wetzel, 1982).

These are growing in the middle part of the pond, at the deepest point. That's been under water apart from a short spell of drought in May, when it was just mud. The other plant is surviving, but not thriving near the pond margin, where it is only under water when the pond is full, which has been a rare occurrence since last winter. 

Grace, James B., and Robert G. Wetzel. "Niche differentiation between two rhizomatous plant species: Typha latifolia and Typha angustifolia." Canadian Journal of Botany 60.1 (1982): 46-57.