Second world record for two Calvatia species (Agaricaceae: Basidiomycota)

Abstract Calvatia is a genus of gasteroid fungi, comprising about 47 species worldwide. In this paper we report the second worldwide occurrence of two poorly known species of Calvatia, recorded in the Cerrado biome of Brazil: C. oblongispora and C. nodulata. Detailed morphological descriptions and illustrations, including scanning electron micrographs of hyphae and basidiospores are provided, as well a discussion on their taxonomy and geographic distribution.


Introduction
The genus Calvatia Fr. (Agaricaceae: Basidiomycota) was proposed in 1849 by Fries, whose representatives are popularly known as puffballs. They are characterized by the globose to pyriform basidioma, gleba pulverulent or cottony, dehiscence by irregular ruptures in the peridium, and not by apical pore (Miller and Miller, 1988;Baseia, 2003).
Comments: Distinctive characteristics that differentiate C. oblongispora from the other species of the genus are the presence of large pores that extend throughout the capillitium, exoperidium with two layers, an outer with interwoven, septate and branched hyphae, and an inner pseudoparenchymatous layer, and elliptical basidiospores with a distinct spiny ornamentation, with spines arranged in ridges along the basidiospore wall (Suárez et al., 2009). We perform all the recommended methods for the herborization of the specimens, however, it was not enough to preserve some characteristics such as the differences between gleba and subgleba, but according to the original description, the gleba is cottony, with yellowish central region, and the subgleba is prominent, concolor to the central portion of the gleba. The specimens of C. oblongispora examined were collected in forest formations in the Cerrado, during the rainy season.
Known distribution: Only known from type locality, Northern Brazil, state of Amazonas (Suárez et al., 2009).
Known distribution: Only known from Northeastern Brazil, states of Ceará and Paraíba (Alfredo et al., 2014). Comments: The distinctive features that differentiate it from the other species of the Calvatia are the presence of nodes in the capillitium, that can be spaced from each other, not having regular arrangement; exoperidium not persistent, likely absent when mature; disappearance of the subgleba, that results in cracks inside the mature basidioma; besides the dark coloration of the gleba and spiny ornamentation of the basidiospores, which are The morphological characteristics observed in the studied specimens coincide with those found in the protologue descriptions of both species. Due to the remarkable characteristics of these species, differentiation through phenotypic comparison can be used. Calvatia guzmanii C.R. Alves & Cortez is a species that also also important characteristics to identify this species (Alfredo et al., 2014).

Discussion
Calvatia oblongispora was described in 2009 based on material collected by Rolf Singer in 1978, in the Amazon, and deposited in the Herbarium of the Instituto Nacional de Pesquisas da Amazônia (INPA) in Manaus, Amazonas, Brazil (Suárez et al., 2009). Calvatia nodulata was described shows the capillitium with abundant pores but differs from C. oblongispora because it shows the exoperidium completely spinose, with pyramidal spines tightly grouped and basidiospores globose, ornamented with short and sharp spines. Calvatia caatinguensis R.L. Oliveira, R.J. Ferreira, B.D.B. Silva, M.P. et al. (Crous et al., 2018) is another species similar to C. oblongispora, however, it has subglobose basidiospores, color variation at the apex of the subgleba and one-layered exoperidium. Suárez et al. (2009) indicated similarities between C. oblongispora and C. sporocristata Calonge, described from Costa Rica (Calonge et al., 2003). Calvatia sporocristata also shows elliptical basidiospores with spines arranged in ridges, however, it differs from C. sporocristata because it has only one pseudoparenchymatous layer in the exoperidium and capillitium without pores. Calonge et al. (2003) and Suárez et al. (2009) also proposed to place both species (C. oblongispora and C. sporocristata) in a new Section Sporocristata Calonge, due to the similarity between the spore ornamentation of the two species, since the species from Calvatia section proposed by Kreisel (1994), have no such ornamentation. A thrid species within the Sect. Sporocristata has been described from Vietnam, C. holothurioides Rebriev (Rebriev, 2013). This species is characterized by the pyriform basidioma and the outer layer of the exoperidium formed by hyphal-vesiculose structures, different from C. oblongispora, which has globose to subglobous basidioma and the outer layer of the exoperidium formed by filamentous hyphae.
Calvatia nodulata differs from all above cited species because the capillitium present numerous nodules along and, when mature, more than half of the basidioma is filled with a cottony subgleba, which has several cavities, besides the dehiscence through the complete release of the exoperidium, exposing the entire gleba. It differs from C. oblongispora, whose dehiscence is due to irregular ruptures of exoperidium, which is not completely detached from the basidioma.
The present study increases the knowledge of the geographic distribution of C. oblongispora and C. nodulata, establishing second world records, the first record of these species for the Cerrado biome, and of the genus in Central-Western region of Brazil.