Perichaena depressa Lib.

Perichaena depressa Lib. View in CoL [0, 9]

Fig. 34 View FIGURES 32–39. 32

Loc 3: On Eur stems, JRM196, 4 September 2008, (mc, pH = 8.0). Loc 4: On Y sp. debris, JRM118, 14 May 2009, (mc, pH = 7.4). Loc 5: On Opr cladodes, JRM195, 27 May 2009, (mc, pH = 8.0), JRM215, 10 September 2008, (mc, pH = 8.0). Loc 7: On Eur stems, JRM131, 28 November 2008, (mc, pH = 7.8). Loc 13: On Agl leaves, JRM212, 28 November 2008, (mc, pH = 8.1). Loc 16: On Ags caudex, JRM210, 16 September 2008, (mc, pH = 8.0), JRM216, 27 May 2009, (mc, pH = 8.0). Loc 18: On Cyt cladodes, JRM211, 13 January 2009, (mc, pH = 8.4).

Mapimí specimens present a great variation in sporocarp shape and size. They have flattened or pulvinated sporocarps, darker or reddish, dispersed or aggregated in small forms, but always with circumcissile dehiscence ( Fig. 32 View FIGURES 32–39. 32 ). Globose spores, 10.3–14.3 diam., slightly larger than original description. Martin & Alexopoulos (1969) & Nannenga-Bremekamp (1991) reported spores of 9–12 µm diam., Lado & Pando (1997) of 10–12 µm diam., and Neubert et al. (1993) of 8.5–11 diam. The capillitium is rather variable with loop filaments and frequently septate. Perichaena depressa and P. quadrata are considered conspecific by Martin & Alexopoulos (1969) but with SEM it is possible to distinguish both species ( Keller & Eliasson 1992). Given the impossibility of reviewing each sample in SEM to differentiate capillitium ornamentation, in this study P. quadrata was considered to be only those specimens of pulvinate sporocarps, aggregated in small forms, 0.3–0.5 mm, with capillitium not completely looped and septate.