The Neotropical Amanita crebresulcata Bas : new citation from Northeast Brazil

(The Neotropical Amanita crebresulcata Bas: new citation from Northeast Brazil). Amanita crebresulcata Bas, a species originally described from the State of Amazonas is reported for the second time out of the Amazon Forest and for the first time in northeast Brazil. Description, discussion and drawings of the species are provided.

Knowledge of this genus in the tropical region of Brazil is poor; only seven species were described from the State of Amazonas by Bas (1978) (Bas & Meijer 1993, Meijer 2006).Recently A. lilloi Singer was found in a public lawn in the State of Pernambuco, Northeast Brazil (Wartchow et al. 2007).
This paper presents this typical Neotropical species reported for the second time outside the Amazon region, in an Atlantic Forest of Northeast Brazil.

Material and methods
Basidiomata were collected in forest fragments located at "Usina São José" (7º50'20''S and 35º00'10''W), Municipality of Igarassu, Pernambuco State.The area comprises approximately 24,000 ha, of which 8,000 ha are forest fragments in different conservation stages.Average annual precipitation is up to 2,000 mm and average annual temperature may be as high as 27 °C (Sectma 2001).
The methodology of this study followed Tulloss et al. (1992) and Tulloss (1993) with a modification.At the beginning of a set of spore data, the notation "[a/b/c]", where a, b and c are related, is to be read "a spores were measured from b basidiomata taken from c collections."When ranges are provided in spore data in the form "(m-) n-o (-p)", the values given are to be understood as follows: m is the smallest value observed or calculated, p is the largest value observed or calculated.In the range of values observed or calculated, the 5 th percentile is n and the 95 th percentile is o.A summary of definitions of biometric variables follows: w cs = breadth of central stratum of lamella w st -near = distance from one side of central stratum to nearest base of basidium w st -far = distance from one side of central stratum to most distant base of basidium on the same side of the central stratum L (W) = average length (width) for spores on a specimen by specimen basis Q = the ratio of length to width of a spore or the range of such ratios for all spores measured Q' = the average of all Q values computed for all spores measured Color names presented are based on Maerz & Paul (1950), and for the identification of the species Bas (1978) was consulted.
Habitat: isolated on soil in tropical rain forest.The broadly ellipsoid, inamyloid basidiospores, very densely sulcate margin of the pileus, and the absence of a typical bulb at the stipe base, place Amanita crebresulcata in Amanita [subgenus Amanita] section Vaginatae (Fr.) Quél.(Bas 1978).However, our collection of A. crebresulcata shows a discrepancy with the original diagnosis of the type from the State of Amazonas: in the type specimen, Bas (1978) described the pileipellis with a 100 µm thick cutis as a subpellis and suprapellis in the form of an ixocutis.The combined elements ranged up to 125 µm thick at the centre of the pileus.In contrast, the recent collection presents a pileipellis difficult to differentiate into sub and suprapellis, apparently comprising solely a cutis up to 180 µm thick at the centre of the pileus.The degree of variation in the character in question is not known.Age of the basidioma, recent rain, humidity, and other factors are very likely to effect both, the thickness of the subpellis, because more and more of it is gelatinized in the appropriate conditions, and the suprapellis, because as it is built up from below by gelatinization of the subpellis, and it is being lost above due to effects of the environment, including rain and desiccation (Tulloss, personal correspondence).On the other hand, the examination of the type showed that size and shape of the spores are similar to our specimen, although only a few undamaged basidiospores had been measured from a poor preserved exsiccatum: [15/1/1] (7.5-)8-10 × (6.5-)7-8.5 µm, (L = 8.9 µm; W = 7.6 µm; Q = 1.11-1.25 (-1.3);Q' = 1.17).
This clampless species differs from A. coacta in sect.Vaginatae mainly by having broader ellipsoid basidiospores (Bas 1978).The third species described in this section from the State of Amazonas, A. craseoderma, also has a gelatinized pileipellis, but there are some distinguishing features: the presence of evanescent dark brown warts on the pileus, the friable volva forming a belt at the stipe base and the (sub)globose spores (Bas 1978).The other clampless Neotropical species, A. antillana Dennis from Trinidad, Martinique and Guadeloupe (Dennis 1952, Pegler 1983), has larger basidiospores, 9.8-13.3× 7.7-10.5 µm, and a friable volva (Tulloss 1994).
Amanita crebresulcata was known previously only from the State of Amazonas, growing near to several tree families, with a case of mycorrhizal connection established with a species of Nyctangiaceae (Bas 1978), from Atlantic Forest areas in São Paulo State, Southeast Brazil (Grandi et al. 1984, Pegler 1997) and dense ombrophilous forest from Paraná (Meijer 2006 as "A. cf. crebresulcata").Now, it is reported in the State of Pernambuco, northeastern Brazil, region where the phanerogamic flora is similar to that of the Amazonian Forest (Ducke 1953, Andrade-Lima 1966).Mycorrhizal associations of A. crebresulcata in the case of our collections were not observed, but the basidiomata were found among trees of Annonaceae, Bignoniaceae, Euphorbiaceae, Erythroxilaceae, Fabaceae, Mimosaceae, and other families.