Trochila colensoi (Berk.) Quijada, 2021

Gomez-Zapata, Paula Andrea, Haelewaters, Danny, Quijada, Luis, Pfister, Donald H. & Aime, M. Catherine, 2021, Notes on Trochila (Ascomycota, Leotiomycetes), with new species and combinations, MycoKeys 78, pp. 21-47 : 21

Trochila colensoi (Berk.) Quijada comb. nov.

Cenangium colensoi ≡ Cenangium colensoi Berk., Hooker, Bot. Antarct. Voy. Erebus Terror 1839-1843, II, Fl. Nov.-Zeal.: 201 (1855). [Basionym]

Pseudopeziza colensoi = Pseudopeziza colensoi (Berk.) Massee, J. Linn. Soc., Bot. 31: 468 (1896)

Notes.

Cenangium colensoi is described from dead leaves of Cordyline sp. ( Asparagales , Asparagaceae ) in New Zealand ( Hooker 1855). The host had been mistakenly reported as Phormium ( Asparagales , Asphodelaceae ) by Berkeley in Hooker (1855) and only recently corrected after re-study of the type collection ( Landcare Research 2020). Cenangium colensoi was later combined in Pseudopeziza and described in more detail by Massee (1896). Both authors commented on the watery-grey disc and brownish receptacle of the apothecia. The apothecia develop among the rigid vascular bundles of the epidermis, first covered by the cuticle, then erumpent and opening by a narrow slit, becoming discoid when mature ( Hooker 1855; Massee 1896). The habit of this fungus fits well with typical macromorphological features of the genus Trochila - a dark brown to black receptacle, which develops beneath the host tissues and eventually becomes erumpent to expose the hymenium by splitting along radial lines or by its splitting into lobes (von Höhnel 1917; Greenhalgh and Morgan-Jones 1964; Dennis 1978; Baral and Marson 2005). Microscopically, P. colensoi was described with a parenchymatous excipulum (angular-globose or isodiametric cells), hyaline under the hymenium and dark brown at the cortex (Berkeley in Hooker 1855; Massee 1896), which is also in agreement with the excipular features of Trochila species. Finally, the hymenium of P. colensoi was described as composed of inamyloid, 8-spored asci with elliptical hyaline ascospores and slender paraphyses (op. cit.).

In 2018, P.R. Johnston collected two specimens (PDD:112240, PDD:112242, Landcare Research 2020) on leaves of Cordyline australis ( Asparagaceae ). The morphology, ecology (host), and locality of these new collections agree with P. colensoi . The photographs of both specimens reveal features such as guttules in ascospores and paraphyses, protruding hyaline cells in the cortical layer of the upper flank and margin, and hyaline gelatinized hyphae covering the dark globose-angular cells of the ectal excipulum at the base and lower flanks. The latter excipular feature of the receptacle is reminiscent of Zhuang’s (1990) description of Calycellinopsis xishuangbanna . An ITS sequence of this species was generated from the recent material (PDD:112240) and included in the Leotiomycetes -wide ITS phylogeny of Johnston et al. (2019). Their results and those in this study (Figs 1 , 2 ) show that P. colensoi is placed among species of Trochila .

Figures

Figure 1. The best-scoring ML tree (- lnL = 87544.854) of Cenangiaceae, Cordieritidaceae, Rutstroemiaceae, Sclerotiniaceae, and the Piceomphale clade, reconstructed from a concatenated six-locus dataset (SSU, ITS, LSU, rpb 1, rpb 2, and tef 1). For each node, the ML bootstrap value (if ≥ 70) is presented above or in front of the branch leading to that node. The arrow denotes the genus Trochila. Species with an asterisk (*) are treated in the Taxonomy section.

Figure 2. The best-scoring ML tree (- lnL = 5225.551) of Cenangiaceae, reconstructed from a concatenated ITS-LSU dataset. For each node, the ML bootstrap value (if ≥ 70) is presented above the branch leading to that node. Species treated in the Taxonomy section are highlighted with gray shading.