Cora hawksworthiana Dal Forno, P. Nelson & Lücking (2017a:178)

Oset, Magdalena, Guzow-Krzemińska, Beata, Flakus, Adam, Rodriguez-Flakus, Pamela & Kukwa, Martin, 2024, New records of Cora species (Hygrophoraceae, Agaricales, lichenized Basidiomycota) from Bolivia confirmed by molecular data, Phytotaxa 670 (2), pp. 83-96 : 88

Cora hawksworthiana Dal Forno, P. Nelson & Lücking (2017a:178)

Description. Thallus foliose, up to 4.5 cm across, composed of 3–7 semicircular, adjacent to subimbricate lobes (0.6–1.6 cm long, 0.5–2.5 cm wide). The colour of the thallus of the analysed specimens was gray, without concentric colour zonation, with cream-coloured margins covered by light dark olive soredia, Upper surface undulate-rugose dry, glabrous but with concentric bands of scattered to dense soredia; involute margins glabrous, densely sorediate; Thallus in section 170–340 µm thick, with upper cortex, photobiont layer, and medulla. Upper cortex diffusely viaduct-shaped, formed by a 15–40 µm thick layer of rather densely packed, irregularly arranged, 4–6 µm thick hyphae supported by a 40–80 µm high ‘medullary’ layer of spaced groups of irregularly arranged, 4–6 µm thick hyphae; photobiont layer 70–120 µm thick, orange-brown, soredia aeruginose-green; hymenophore absent (cf. Lücking et al. 2017a and own observation).

Chemistry. No substances detected by TLC.

Distribution and ecology. The records of C. hawksworthiana presented here are the first records from Bolivia. The species was found in Andean Yungas forest and Boliviano-Tucumano forest at 1943-2250 m a.s.l. in the departments Santa Cruz and Tarija. Besides in Bolivia C. hawksworthiana was noted in Colombia (northern Andes), Costa Rica and in subalpine to temperate rain forest regions in Chile ( Lücking et al. 2017a).

Notes. Cora hawksworthiana is one of few sorediate species in the genus It can be easily recognized due to the heavily sorediate margins and the formation of concentric bands of soredia also on the lobe surface ( Lücking et al. 2017a). It is broadly distributed as another sorediate species, C. soredavidia Dal-Forno, Marcelli & Lücking , which has a very similar morphology, but C. hawksworthiana forms larger thallus with more prominent, broadly marginal bands of soredia on the surface. Above this, the thallus is darker and the hymenophore differently developed. Despite similarities in morphology, the two taxa are not phylogenetically related ( Lücking et al. 2017a).

Cora hawksworthiana is a part of the Cora aspera clade which includes e.g., C. aspera Wilk, Lücking & E. Morales , C. corani Lücking, E. Morales & Dal-Forno , C. minutula Lücking, B. Moncada & Yánez-Ayabaca , or C. pseudocorani Lücking, E. Morales & Dal-Forno. The clade includes mostly epiphytic taxa with more or less green thallus when fresh, frequently forming medullary papillae and growing mostly in montane forest (see Lücking et al. 2017a). Within the clade, only C. hawksworthiana and C. minutula produce soredia, but the latter has irregular, dark olive lobes with uneven surface and occasionally forms soredia on the underside ( Lücking et al. 2017a).

The species is similar to three other medium-sized species with papilliform appendages on the lower medullary hyphae, C. davidia B. Moncada, L. Vargas & Lücking, C. inversa Lücking & B. Moncada and C. totonactorum B. Moncada, R. -E. Pérez & Lücking. C. davidia and C. hawksworthiana are the largest sorediate, epiphytic species and have the widest distribution ranges in the genus, suggesting that conspicuous epiphytic species with soredia disperse more easily than other species. Cora davidia differs predominantly by its sparse soredia, the thinly pilose surface and the corticolous habitat. Cora inversa and C. totenctorum are cryptic morphologically and anatomically, but distantly related to C. hawksworthiana , and differ only phylogenetically ( Moncada et al. 2019). Other sorediate species such as C. paraminor Dal-Forno, Chaves & Lücking , C. pastorum B. Moncada, Patiño & Lücking and C. rothesiorum B. Moncada, Madriñán & Lücking produce smaller thalli and most of them belong to the C. minor clade (see Lücking et al. 2017a).

Specimens examined. Bolivia, Dept. Santa Cruz, Prov. Comarapa, Remate, 2250 m, 17°52’11”S, 64°20’53”W, Yungas forest with big trees, partly grazed, 15 May 2017, leg. A. Flakus s.n. (KRAM-L-68956, LPB) ; Dept. Tarija, Prov. Burnet O‘Connor, la Cumbre close to Entre Ríos, old road between Entre Ríos and Tarija, 21º27’48”S, 64º13’24”W, 1943 m, Boliviano-Tucumano forest with Podocarpus, 28 July 2015, leg. A. Flakus 27379 (KRAM-L- 49637, LPB) .