Leucoagaricus atroviridis Y.R. Ma, Z. W. Ge & X.D. Yu, sp. nov. Figures 4 and 5. MycoBank: MB 843382
Etymology: atroviridis (Latin) refers to the bottle-green to dark brown radially fibrillosesquamules on the pileus.
Diagnosis: Leucoagaricus atroviridis is characterized by bottle-green to dark brown,fibrillose squamules, and broadly clavate cheilocystidia with obvious refractive contents.
Type: CHINA. Liaoning Province: Shenyang, Shenyang Agricultural University,August 2020, X.D. Yu (SYAU FUNGI 073, holotype).GenBank Acc. No.: ITS = OM976852, LSU = OM976868
Description: Pileus 48–114 mm in diameter, covered with bottle-green (1E7) to darkbrown (2F6) radially fibrillose squamules, umbonate. Context, white (1A1), up to 4 mmthick at center, no change in color when bruised. Lamellae-free, crowded, white (1A1), edgefinely scalloped. Stipe, 69–73×6–10 mm, white (1A1), smooth, hollow, subcylindrical orattenuate upwards with bulbous base up to 13–16 mm wide. Annulus, white (1A1), locatedat the middle to upper part of the stipe. Flavor and odor not recorded. Spore print not recorded.
Basidiospores [60/3/2], 5.5–7.0(7.5)×4.0–5.0µm, Q = (1.10)1.22–1.50(1.63),Qm= 1.36 ±0.11,ellipsoid to ovoid from side view and front view, without germ pore, hyaline, smooth, slightlythick-walled (about 0.5µm); dextrinoid, metachromatic. Basidia, 17.0–28.0×7.5–10.0µm,clavate, hyaline, four-spored, rarely two-spored; sterigmata, 3.5µm long. Cheilocystidia,21.5–33.5×9.5–15.5µm, hyaline, broadly-clavate to broadly fusiform, thin-walled. Somecheilocystidia with obvious refractive contents on the apex. Pleurocystidia absent. Lamellartrama, subregular. Pileus squamules composed of 5.0–8.5µm wide subcylindrical repenthyphae with light greenish (30B5) to light brownish (3B3) intracellular pigments. Stipitipel-lis composed of cylindrical to slightly inflated hyphae, 5.0–11.0µm in diameter, hyaline. Clamp connections absent in all parts of the basidiomata.
Habitat and Habit: solitary in grass in summer. So far, known only in Shenyang,Liaoning Province in northeastern China.
Other specimens examined: CHINA. Liaoning Province: Shenyang, Shenyang Agri-cultural University, August 2020, X.D. Yu (SYAU FUNGI 074).
Comments: Macroscopically, Leucoagaricus atroviridis is characterized by medium tolarge basidiomata, stipe with a bulbous base and bottle-green to dark brown fibrils.
Phylogenetically, Leucoagaricus atroviridis is close to Leucoagaricus truncatusZ. W. Ge & Zhu L. Yang and Leucoagaricus purpureolilacinus Huijsman (Figure 1). However,La. purpureolilacinus, originally described in the Netherlands, has a purplish brown pileusand clavate to subfusiform cheilocystidia [6]. La. truncatus, originally described in Sichuan,southwestern China, differs in having a truncated pileus with orange–white to gray–orangesquamules and larger basidiospores [11].
