Potential Desiccation Tolerance Shown in Cheilanthes ecuadorensis (Pteridaceae)

Potential Desiccation Tolerance Shown in Cheilanthes ecuadorensis (Pteridaceae).—Having enough water for survival is one of the restrictions with which organisms must cope. Many strategies have evolved that allow organisms to survive in low-water conditions. Among plants, one such strategy is desiccation tolerance: the ability to survive an almost complete loss of water in photosynthetic tissues (Walter, Annual Review of Plant Physiology 6:239–252. 1955; Schwab & Heber, Planta 161:37–45. 1984; Gaff, in Structural and Functional Responses to Environmental Stresses, 225–268. 1989; Rascio & La Rocca, Critical Reviews in Plant Sciences 24:209–255. 2005), a strategy that is also found in other organisms such as lichens. Although desiccation tolerance is likely the ancestral state for all land plants (Gaff & Oliver, Functional Plant Biology 40:315–328. 2013), vegetative desiccation tolerance has arisen multiple times since their move to land (Oliver et al., Plant Ecology 151:85–100. 2000; Oliver et al., Integrative and Comparative Biology 45:788– 799. 2005; Kirkpatrick, PhD Dissertation. 2008). It remains broadly uncommon, except in certain groups such as bryophytes (Proctor et al., The Bryologist 110:595–621. 2007). However, it appears to be relatively common in the xericadapted members of Pteridaceae (i.e., cheilanthoid ferns), being reported in several species of Astrolepis (Kirkpatrick, PhD Dissertation. 2008), Cheilanthes s.l. (Gaff, Oecologia 74:133–136. 1987; Proctor & Tuba, New Phytologist 156:327–349. 2002; Kirkpatrick, PhD Dissertation. 2008), Notholaena (Kessler & Siorak, American Fern Journal 97:175–185. 2007) and Pellaea, as well as in Argyrochosma fendleri and Bommeria hispida (Kirkpatrick, PhD Dissertation. 2008). Here I present a further record of potential desiccation tolerance exhibited in cheilanthoid ferns, describing very broadly time to desiccation and recovery in Cheilanthes ecuadorensis Windham & K.Sosa, a recently described species from Ecuador that is known only from herbarium specimens (Sosa et al., Systematic Botany 46:249–259. 2021).