EPOW - Ecology Picture of the Week

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Guanaco Bush Ablaze

Credit & Copyright:  Dr. Bruce G. Marcot
  

Explanation:  Fire on the hill!   Well, not really, so what are these bright outbreaks on this grassland hillside, here in a remote Patagonian valley in southern Chile? This is a plant called guanco bush, which is endemic to this Patagonian steppe country.  It is in full flower of bright scarlet, as if the hillside is bleeding through its pores, giving the plant its other common name of "fire tongue." Guanco bush (or fire tongue) grows as a "cushion shrub" in rocky, grassy, steppe-type conditions, only in southern Chile and Argentina.   The name guanaco bush refers not to any use of the plant by guanacos -- that are relatives of the llama and that also inhabit these Patagonian grasslands -- but rather to how the plant looks like a guanaco when it lies down.           One study (Cosacov et al. 2012) found that this plant occurs in refugia in Patagonia, signaling that it survived the Last Glacial Maximum, and that three population centers of the plant show different patterns of survival and spread.   Another study (Paiaro et al. 2012) found that differences in leaf and flower shapes among populations of this plant have resulted not from grazing by guanacos or by other biology influences, but more directly by the non-living (abiotic) environment, principally differences in temperature and soil potassium content.     Information:      Cosacov, A., L.A. Johnson, V. Paiaro, A.A. Cocucci, F.E. Cordoba, and A.N. Sérsic.  2012.  Precipitation rather than temperature influenced the phylogeography of the endemic shrub Anarthrophyllum desideratum in the Patagonian steppe.  Journal of Biogeography 40(1):168-182.      Paiaro, V., G.E. Oliva, A.A. Cocucci, and A.N.Sérsic.  2012.  Geographic patterns and environmental drivers of flower and leaf variation in an endemic legume of Southern Patagonia.  Plant Ecology & Diversity 5(1):13-25.