Trachypogon plumosus (Poaceae,Andropogoneae): ancient thatch and more from the ceren site,El Salvador

Paleoethnobotanical studies in the Zapotitdn Valley of north-central El Salvador revealed that a species of grass,Trachypogon plumosus, was in common use as a thatch material at the Ceren site, a small mesoamerican farming community inundated by volcanic ash circaa.d. 590. Although the grass must have been common in Precolumbian times, repeated attempts to collect fresh specimens from the modern valley were unsuccessful. A survey of the major herbaria with collections from El Salvador likewise demonstrated a lack of modern specimens from the Zapotitdn Valley. The elimination of theT. plumosus from this area and its characteristic savanna habitat probably occurred as a result of the introduction of competing Old World grasses and excessive herbivory. This finding demonstrates why conservationists working in the tropics should be concerned not only with the extinction of rain forest habitats, but with the elimination of other habitats as well.