CONSERVATION OF THE CIENEGA ENDEMIC, ERYNGIUM SPARGANOPHYLLUM HEMSL. (APIACEAE)

Abstract

Eryngium sparganophyllum is an imperiled plant species with a small geographic range in the southwestern United States and northern Mexico and is restricted to wetlands known as cienegas. We compiled information on its population status, habitat, life history, and threats to inform conservation and recovery efforts and to guide future research. Of the six historically documented populations, this species has been extirpated at two and remains extant in four. Extractions of groundwater or diversions of spring discharge are the greatest threats, exacerbated by reduced groundwater inflow to cienegas because of regional drought and temperature increases. Eryngium sparganophyllum is locally common in its known sites, but woody encroachment may be a threat, as field data in Arizona reveal the plants to be more abundant in open sun than under tree canopy. Plants flower within their first year and host a wide range of invertebrate visitors. Experimental techniques confirm seed viability with a morphophysiological dormancy; however, patterns of seedling establishment in the wild remain undocumented. Reintroduction at two sites is being implemented and long-term monitoring of survivorship and fecundity of these transplants is necessary to guide future recovery efforts.