Tetrorchidium brevifolium Standl. & Steyerm. is reported for the first time from Panama and T. trichotocarpum McPherson is described, differing from those of its congeners also furnished with a 3-carpellate gynoecium and a glabrous cuplike pistillate disk, by its combination of subentire leaves, small petiolar glands, small stipules, near absence of pistillate bracteal glands, densely pubescent ovary, and occurrence in central Panama. A key to the six species of Tetrorchidium Poepp. (Euphorbiaceae) now known to occur in Panama is presented.