Kilian, N. & Smalla, B.: Ageratum salvanaturae (Eupatorieae, Compositae), a new species from the National Park El Imposible, Ahuachapán, El Salvador. — Willdenowia 31: 137–140. 2001. — ISSN 0511-9618.
Ageratum salvanaturae, an eglandular, epappose and epaleate herb with its capitula regularly aggregated in compact, globular synflorescences, is described as a species new to science and illustrated. It is known only from five collections made at medium altitudes in the El Imposible National Park in NW El Salvador near the border with Guatemala. Its relationship is uncertain.