Cryptothecia rosae-iselae Flakus & Kukwa, 2015

Ertz, Damien, Flakus, Adam, Oset, Magdalena, Sipman, Harrie J. M. & Kukwa, Martin, 2015, A first assessment of lichenized Arthoniales in Bolivia with descriptions of two new species, Phytotaxa 217 (1), pp. 1-25 : 9

Cryptothecia rosae-iselae Flakus & Kukwa sp. nov. ( Fig. 4 ) MycoBank no. MB 812570

Diagnosis: Similar to Cryptothecia lichexanthonica but differs in wider ascospores, smaller asci, the production of gyrophoric and lecanoric acids, and the constant lack of brownish pigmentation around the asci.

Type: — BOLIVIA. Dept. Santa Cruz: Prov. Cordillera, Parque Nacional y Área Natural de Manejo Integrado Kaa-Iya del Gran Chaco, near Peto Blanco, 18º56’26”S, 60º22’39”W, 340 m, Chiquitano forest, on bark, 5 December 2011, M. Kukwa 10630 (holotype UGDA!, isotype LPB!).

Thallus corticolous, delimited by prothallus of white or brownish hyphae; thallus surface smooth, matt, ecorticate, greenish grey or rarely beige grey; ascigerous areas delimited, round to irregular in outline, raised above the thallus, up to 0.75 mm diam., single or more often fused in groups of rows, white, ascigerous layer up to 175 μm high, I+ blue K/ I+ blue; asci I–, K/I–, never encapsulated by a brownish pigmentation, 8-spored, globose, 100–110 μm in diam., with a 5–8 μm thick wall, entangled by strongly ramified and anastomizing, 1–2 μm wide paraphysoids; ascospores hyaline, muriform, ovoid, with 9–12 transverse and up to 5 longitudinal septa, (50–)60–73 × (24–)28–36 μm; conidiomata not observed.

Chemistry: thallus C+ pink red, K–, P–, UV+ orange; lichexanthone, gyrophoric and lecanoric acids detected by TLC.

Etymology: The new species is dedicated to our friend, Rosa Isela Meneses Quisbert, the Director of the Herbario Nacional de Bolivia, Universidad Mayor de San Andrés in La Paz, for generous support of lichenological studies in Bolivia.

Distribution and ecology: The species is known from Santa Cruz Department in Bolivia where it occurs in Chiquitano or Chiquitano-Chaqueño forest types.

Notes: Cryptothecia rosae-iselae is the fourth species of the genus containing lichexanthone and is the most similar to C. lichexanthonica . The latter however lacks gyrophoric and lecanoric acids, has larger asci (150–300 μm in diam.), which are often surrounded by dark brown tissue, and narrower (up to 28 μm wide) ascospores ( Lima et al. 2013).

Cryptothecia assimilis Makhija & Patw. , which also contains lichexanthone, can be separated by the pedicellate and pyriform asci, larger (mostly over 1 mm in diam.) ascigerous areas and the lack of gyrophoric and lecanoric acids ( Makhija & Patwardhan 1994; Lima et al. 2013). The third species producing lichexanthone, C. darwiniana , has clearly pedicellate asci with very thick (c. 21 μm) walls and additionally produces confluentic acid (Bungartz et al. 2013).

Additional specimens examined (all corticolous). BOLIVIA. Dept. Santa Cruz: Prov. Cordillera, KAA-IYA, near Tucavaca colony, 18º30’19”S, 60º57’14”W, 278 m, Chiquitano forest , 4 December 2010, AF 18981, 19107, 19127 & JQ (KRAM, LPB) ; between Tucavaca colony and National Park border, 18º31’40”S, 60º41’26”W, 314 m, Chiquitano forest , 4 December 2010, AF 19234 & JQ (KRAM, LPB) ; near Peto Blanco, 18º56’26”S, 60º22’39”W, 340 m, Chiquitano forest , 5 December 2011, AF 23635, 23669, 23674 (KRAM, LPB) ; near Peto Blanco, 18º51’36”S, 60º18’00”W, 290 m, transition Chiquitano-Chaqueño forest , 5 December 2011, AF 23723 (KRAM, LPB) ; near Peto Blanco (park guard’s station), 18º48’25”S, 60º14’54”W, 330 m, transition Chiquitano-Chaqueño forest , 6 December 2011, MK 10702 (LPB, UGDA) .

Figures

FIGURE 4. Cryptothecia rosae-iselae (holotype). A, habit of thallus with ascigerous areas; B, edge of the thallus with black prothallus; C, ascus with five ascospores (mounted in LPCB); D, ascus wall (mounted in LPCB); E, paraphysoids covering ascus (mounted in LPCB); F, ascospores (mounted in water); G, ascospores (mounted in LPCB). Scales:A–B—1 mm; C—50 μm; D–G—10 μm.