Contribution to the knowledge of Camillea (Ascomycota, Graphostromataceae) in the Amazon forest in Pará, Brazil

Three species of the Ascomycetes genus Camillea were recorded in a fragment of Amazon rainforest in the region of Santarém, Pará state, Brazil. The occurrence of C. leprieurii, C. cyclops and C. bilabiata expand the range of distribution of these species in the state. Camillea leprieurii has previous records in the regions of Marabá, Oriximiná, Itaituba and Novo Progresso, while C. cyclops had been recorded in the west of the state. This is the first record of C. bilabiata for Pará. We provide a morphological description of the specimens and an identification key for Camillea species found in Pará.

Camillea species generally have columnar (e.g. C. leprieurii (Mont.) Mont.), flattened (e.g. C. heterostoma (Mont.) Laessøe, J.D. Rogers & Whalley) or discoid stroma (e.g. C. labellum Mont.), bipartite with dehiscent ectostromas, lightly colored and ornamented ascospores without visible germ slits (Laessøe et al. 1989;Hastrup and Laessøe 2009), although C. labiatirima J.D. Rogers, F. San Martín & YM Ju has almost smooth ascospores with germ slits (Rogers et al. 2002). The genus is almost exclusively confined to the Americas and concentrated mainly in the Amazon region (Hastrup and Laessøe 2009 (Pereira 2015;Santana et al. 2018;CRIA 2020;Flora do Brasil 2020), evidencing the lack of data on fungal diversity in this region of great biological importance (Maia et al. 2015). Here we provide new occurrence records for Camillea species that expand their distribution in Pará. We include morphological descriptions and an identification key for Camillea species in Pará.
Camillea specimens were collected during excursions to fragments of Amazon rainforest near the Silvio Braga hydroelectric power plant (HPP) (2°48'44.45"S, 54°17'56.23"W) in western Pará state, Brazil, in November 2017 and April and July 2018. The fragments present around 30,000 ha each, and for the most part, they are in a plateau area with little variation (Silva 1966), covered with highcanopy forest, understory dominated by natural regeneration, herbaceous and shrub plants, palm trees and bushes.
The primary vegetation cover in the region is dense ombrophilous forest (Veloso et al. 1991). The climate is xeroquimenic (Bagnouls and Gaussen 1963), with an average temperature of 27 ºC (± 5 o C) and average relative humidity of about 88%. The average annual rainfall is 2,200 mm, with a rainy season from January to May (monthly average of 231 mm) and a dry season from June to December (monthly average of 61 mm) (Alvares et al. 2013).
Fungal specimens were removed from the substrate with the help of a pocket knife and placed in paper bags as proposed by Lodge et al. (2004). They were dehydrated at 38 °C for 48 hours, for taxonomic identification. Macroscopic stroma characteristics were observed as described by Laessøe et al. (1989), San Martin González and Rogers (1993), Whalley (1995) and Hastrup and Laessøe (2009). Microscopic characteristics were not observed, but the species were easily identified in the field (Hastrup and Laessøe 2009). Reference samples were deposited in the fungi collection of the HSTM herbarium of Universidade Federal do Oeste do Pará (UFOPA).
In Pará, C. leprieurii is the most representative species, occurring in the regions of Marabá, Oriximiná, Itaituba and Novo Progresso. Camillea mucronta and C. cyclops were recorded only in the western region of the state (Santana et al. 2018;CRIA 2020). This study reports C. bilabiata as a new record for the state of Pará (Figure 1). The material in this study agrees with the description of Hastrup and Laessøe (2009) and Pereira (2011). Silveira and Rodrigues (1985) began their studies in the Amazon, with specimens from the states of Amazonas and Mato Grosso, reporting five species of Camillea, among which C. bilabiata, C. cyclops and C. leprieurii were listed, in addition to C bacillum and C. labellum. Hypoxylon cyclops Mont., Annales des Sciences Naturelles Botanique 13: 353 (1840).

Taxonomy
Eroded cylindrical stroma with 3-5 mm in diameter, with a flat apical, circular disk surrounded by a ring below, carbonaceous and black, each containing 6-8 perithecia located in its central region. Papillary ostioles emerge in a ring below the apical disc. Ascus and ascospores not seen. The examined specimens are similar to those examined by Laessøe et al. (1989). Eroded, erect, with 3-5 mm in diameter, with concave surface and bilabial apex, brownish black, glabrous stromata, gregarious. Carbonaceous, brittle perithecia form long individual channels that merge into a common channel just below the ostiole. The characteristics of the examined specimens are similar to the descriptions by Laessøe et al. (1989) and Hastrup and Laessøe (2009).   Eroded, squamous white, cylindrical stromata, with 2.5-3 mm in diameter and 15-20 mm high, attached to the substrate after the upper part was broken off, with discoid apex up to 1 mm deep, with rounded and narrow margin. Elongated, ovoid perithecia with individual ostioles. Ostioles along the margin of the depression, individually eroded into annular and papillary depressions. The characteristics of the examined specimens are similar to the description by Laessøe et al. (1989). Xylariales are uncertain due to the lack of molecular data, as well as overlapping morphological characteristics (Daranagama et al. 2018), which is why Camillea is rarely addressed in scientific studies. In addition, the fragile material is rarely in good condition to obtain cultures and allow sequencing, which is reflected in the limited number of accessions from this genus in GenBank/NCBI. Of 27 deposited sequences for Camillea, only one is from a species recorded in this study (Camillea cyclops, with a registered sequence # MF038958.1; NCBI 2020).
In Brazil, including this study, there are 162 records of C. leprieurii, 32 of C. bilabiata, 42 of C. cyclops and 16 of C. mucronata (CRIA 2020; Flora do Brasil 2020). These numbers, as well as the diversity of Graphostromataceae, are expected to be higher, especially in the Amazon, that harbors great mycological diversity (Hawksworth 2001), but where the scarce number of professionals and difficult access to isolated areas are obstacles to large-scale fungal surveys.