T. latifolia: aquatic; stems erect, reed-like, 3-6 feet high; leaves long, erect, linear, sheathing at the base, flat above; flowers in a dense continuous spike, often more than a foot long, the upper male portion yellow, the lower part dark brown. - Cat's-tail or Reed-mace. - Margins of ponds, lakes, and ditches. Fl. June, July.

T. angustifolia, which is not quite so common, differs chiefly in the interruption in the spike between the male and the female flowers, for a space varying from a few lines to an inch in length, and in having narrower stifter leaves, and more slender spikes.