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Page number:437 
Remarks (internal):The caespitose habit, plano-convex or applanate pileus with papillate umbo, 6-9-angled basidiospores with blunt angles, and the abundant cheilocystidia are distinctive for E. caespitosum.
The holotype consists of caespitose basidiocarps in good condition, and another collection (GDGM 15619) in GDGM was also cited by Zhang et al. (1994a) in the protologue of E. caespitosum. Re-examination of the voucher collections showed that — contrary to the original description — the pileus is umbonate with a striate margin, most basidia have four slender sterigmata, and apically acute clavate pleurocystidia are absent from the hymenium.
In the same publication, Zhang et al. (1994a) described a later collection from the same area (GDGM 16726) as E. carneobrunneum, said to differ from E. caespitosum mainly by the absence of pleurocystidia. However, we found no differences between the two holotypes in macro- and microscopic characters. Comparisons of the E. caespitosum specimens and four E. carneobrunneum collections (GDGM 18333, GDGM 24136, GDGM 24025, and GDGM 24026) revealed no convincing morphological or ITS sequence (Fig. 3) differences between the two taxa. Therefore, we consider E. carneobrunneum a synonym of E. caespitosum.
A 2009 collection (GDGM 27564) from the E. caespitosum type locality provided additional information for this taxon (Fig. 1). It has mostly the same characters (caespitose habit, plano-convex pileus with distinct papillate umbo, thin-walled basidiospores with 6-9 angles in profile view, abundant cheilocystidia forming a sterile edge) as cited in the protologue of E. caespitosum, but has a carneous white pileus in the field as shown in the photographs (Fig. 1). As it otherwise shares the same diagnostic characters with E. caespitosum, we revise the pileus color to carneous white to carneous brown based on the holotype and the new material. In addition, GDGM 27564, GDGM 24025 and GDGM 24026 cluster together phylogenetically with high statistical support based on rDNA ITS sequence data (Fig. 3). Unfortunately, no DNA sequences were successfully generated from the holotype.
Another scattered to caespitose species, E. mastoideum T.H. Li & Xiao Lan He, described recently from South China, shares with E. caespitosum a plano-convex to applanate pileus with papillate umbo (He et al. 2011). However, E. mastoideum has larger basidiospores (9.5-12(-13) x 7-8(-8.8) µm). Furthermore, the molecular data indicated that the two species are quite different from each other (Fig. 3).
Description type:Non-original description 
Description:Entoloma caespitosum W.M. Zhang, Acta Mycol. Sin. 13: 192, 1994. Figs 1-2
≡ Entoloma carneobrunneum W.M. Zhang, Acta Mycol. Sin. 13: 193, 1994.
Revised description
Basidiomata medium-sized. Pileus 2-5 cm broad, conical to convex at first, expanding to plano-convex, applanate or upturned with a very pronounced, papillate umbo, slightly to distinctly striate almost up to center, dry, not hygrophanous, smooth, with straight and entire to crenulate margin sometimes exceeding gills, pale brown to brown at the umbo, paler elsewhere, carneous white (4B2) to carneous brown (7C3). Lamellae adnate-emarginate to adnexed, subventricose, up to 4 mm broad, white at first becoming pinkish with age, moderately crowded, thin, with concolorous and irregular edge, with 3-4 tiers of lamellulae. Stipe central, 30-90 x 2-6 mm, cylindrical, equal, smooth, slightly polished, surface dry, concolorous with or slightly paler than pileus, hollow, brittle, with white tomentum at base. Context white, thin. Odor not distinctive, taste not known.
Basidiospores 8.5-10.5 x 6-7.5 µm, Q = 1.23-1.54, heterodiametric, relatively thin-walled, 6-9-angled with blunt angles in profile view. Basidia 30-45 x 8-12 µm, clavate, 4-spored, sometimes 2-spored. Lamellar edge sterile. Cheilocystidia in clusters along the lamellar margin, 30-80 x 5-11 µm, cylindrical to narrowly clavate, hyaline, thin-walled. Pleurocystidia absent. Hymenophoral trama parallel, made up of cylindrical elements, 50-110 x 5-16 µm. Pileipellis a cutis, made up of repent hyphae, terminal cells cylindrical to subclavate, 5-12 µm wide, with pale yellow brownish, intracellular pigment. Pileitrama regular, consisting of cylindrical hyphae. Stipitipellis a cutis of cylindrical to subclavate hyphae, 3-9 µm in diameter. Brilliant granules very abundant in lamellar trama and pileitrama. Oleiferous hyphae abundant in lamellar trama. Clamp connections absent in all tissues.
Habitat: Scattered to caespitose, on sandy soil of tropical rainforest with Ficus, Castanopsis, Machilus, Cyclobalanopsis, and Taxodiaceae.
Specimens examined - China. Hainan Province: Ledong County, Jianfengling National Forest Park, at 18°36ʹ-52ʹN 108°40ʹ-109°02ʹE, alt. 680-730 m, 21 October 1988, Chen Huan-Qiang (GDGM 16476, holotype); 21 August 1988, Chen Huan-Qiang (GDGM 15619); 28 July 2009, Li Tai-Hui & Huang Hao (GDGM 27564); 850-900 m, 11 June 1990, Chen Huan-Qiang (GDGM 16726, holotype of E. carneobrunneum);
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