Amanita subparvipantherina Zhu L. Yang, Qing Cai & Yang Y. Cui.
Index Fungorum number: IF551335; Facesoffungi number: FoF00899
Basidiomata medium-sized. Pileus 5–7 cm in diam., at first hemispherical, then convex to plano-convex, center often slightly umbonate, yellowish brown (4A4–5, 4B4–7) to brown (4C5–8) or dark brown (4D6–8, 4E6–8), becoming yellowish (4A2–4) to brownish (4B3–4, 4C3–4) toward margin, viscid when moist; margin tuberculate-striate (0.2–0.3R), non-appendiculate; volval remnants as conical, subconical to granular, dirty white to grayish (3B1–2) to brownish (3A2–4; 3B2–3), randomly arranged, small warts; trama white (1A1), unchanging. Lamellae free, white (1A1), crowded; lamellulae truncate, plentiful, evenly distributed. Stipe 11–16.8×0.8–2 cm, subcylindric or slightly tapering upward, with apex slightly expanded, whitish (1A1), with yellowish brown (3B2–4) tinge, often glabrous to subglabrous, rarely covered with white (1A1) floccose squamules; context white, hollow in center; basal bulb subglobose to ovate to napiform, 2–3 cm in diam., white (1A1), upper part covered with subconical to granular greyish to brownish volval remnants, often forming a short limbate collar on the stipe base. Annulus present, superior to median, pendant from attachment 2–4 cm below apex of stipe, white (1A1), thin, membranous, fragile. Odour indistinct. (Fig.2)
Lamellar trama bilateral. Mediostratum 25–40 μm wide, composed of abundant fusiform, ellipsoid to long ellipsoid inflated cells (20–200×10–55 μm); filamentous hyphae abundant, 3–7 μm wide; vascular hyphae rare. Lateral stratum composed of abundant fusiform to ellipsoid inflated cells (20–45×10–20 μm), diverging at an angle of ca. 30–45° to the mediostratum; filamentous hyphae abundant, 2–6 μm wide; septa without clamps. Subhymenium 25–40 μm thick, with 2–3 layers of ellipsoid or irregularly shaped cells, 10–28×7–10 μm. Basidia 30–40×9–13 μm, clavate, 4-spored, rarely 2-spored; sterigemata 3–5 μm long; basal septa without clamps. Basidiospores [140/7/5] (8–)9–11.5(−13)×(5.5–)6.5–8(−9.5) μm [Q= (1.20–)1.28–1.5(−1.69), Qm=1.38±0.11], broadly ellipsoid to ellipsoid, rarely elongate, inamyloid, colourless, hyaline, thin-walled, smooth; apiculus small. Lamellar edge appearing as sterile strip, composed of inflated cells, mixed with abundant thin-walled, yellow brownish filamentous hyphae. Pileipellis 100–200 μm; upper layer (50–100 μm thick) strongly gelatinized, composed of radically to subradically, thin-walled, colourless to nearly colourless, filamentous hyphae 2–6 μm wide; lower layer (50–110 μm thick) composed of compactly arranged, filamentous hyphae 3– 8 μm wide; vascular hyphae rare. Volval remnants on pileus composed of somewhat irregularly arranged elements; inflated cells fairly abundant to abundant, fusiform to ellipsoid to subglobose (25–50×15–40 μm), single and terminal or in chains of 2–3 and then terminal, thin-walled, colourless to yellowish vacuolarly pigmented; filamentous hyphae very abundant, 2–10 μm wide, thin-walled, nearly colourless to yellowish vacuolarly pigmented; vascular hyphae rare. Interior of limbate collar on the stipe base composed of longitudinally to somewhat irregularly arranged elements; inflated cells fairly abundant, fusiform, ellipsoid, broadly clavate to pyriform (30–75×15–45 μm), becoming more abundant toward the outer surface of limbate collar, colourless to nearly colourless, thin-walled to slightly thick-walled, single, sometimes two in chains; filamentous hyphae abundant to very abundant, 2–10 μm wide, colourless to nearly colourless, thin-walled; vascular hyphae rare. Outer surface of limbate collar similar to the interior but with more abundant inflated cells; inner surface of limbate collar gelatinized, composed of 3–8 μm wide filamentous hyphae. Stipe trama composed of primarily of longitudinally arranged, long clavate, terminal cells 210–350×25–45 μm; filamentous hyphae scattered (in interior), to fairly abundant (on stipe surface), 6–16 μm wide; vascular hyphae rare. Annulus composed of loosely and subradially arranged elements; inflated cells fairly abundant, clavate, ellipsoid to long ellipsoid (35–65×15–25 μm), colourless to nearly colourless, thin-walled, single and terminal, rarely two in chains and then terminal; filamentous hyphae abundant to very abundant, 2.5–6 μm wide, colourless to nearly colourless, thin-walled; vascular hyphae rare. Clamps absent in all parts of basidioma. (Fig. 3–5)
Habitat and distribution: Solitary or gregarious in subtropical forests composed of Pinus, Quercus, Keteleeria and Rhododendron. Common in southwestern China.
Material examined: CHINA, Yunnan Province, Binchuan County, Jizu Mountain, Pinus mixed with Quercus and Rhododendron (altitude 2000–2100 m), 11 August 2011, Q. Cai 657 (HKAS 70252); the same location, 9 August 2014, Q. Cai 1288 (HKAS 83757); Chuxiong City, Zixi Mountain, Pinus and Quercus (altitude 2000 m), 17 June 2008, Z. W. Ge 2035 (HKAS 54231); Jingdong County, Ailao Mountain, Pinus and Quercus (altitude 2500 m), 15 July 2008, L. P. Tang 333 (HKAS 54564); Longyang District, Haitangwa Village, Pinus and Quercus (altitude 2400 m), 12 August 2011, Y.J. Hao 485 (HKAS 71594); Lushui County, Luzhang Town, Xiapianma Village, Pinus (altitude 2000 m), 7 August 2010, Q. Cai 291 (HKAS 67853); Tengchong County, Guanpojiao Village, Pinus, Quercus, Keteleeria and Rhododendron (altitude 1800 m), L. P. Tang 860 (HKAS 56817); Yongping County, Shangzhai Village, Pinus and Quercus (altitude 1991 m), 30 July 2009, L. P. Tang 1029 (HKAS 56986, holotype!).
Notes: Amanita subparvipantherina is distinguished by its slender basidioma with a long stipe, broadly ellipsoid to ellipsoid basidiospores (9–11.5×6.5–8 μm), volval remnants on the pileus and the limbate collar on the stipe base, composed of abundant to very abundant filamentous hyphae, mixed with fairly abundant inflated cells. Amanita subparvipantherina is similar to A. parvipantherina. However, A. parvipantherina has floccose to granular volval remnants on the upper bulb, and volval remnants on the pileus with more abundant to nearly dominant inflated cells. Amanita subparvipantherina is also somewhat similar to A. sychnopyramis f. subannulata. However, the latter taxon has volval remnants on the pileus, with more abundant to nearly dominant inflated cells, and globose to subglobose basidiospores (6.5–8.5×6–8 μm) with Q=1.03–1.16. Amanita subparvipantherina may be confused with A. subglobosa Zhu L. Yang, a species described from southwestern China, in their brownish pileus with white to yellowbrown conical volval remnants on the pileus. However, A. subglobosa has a larger basidioma, a distinctly globose to subglobose bulb on the base of the stipe, volval remnants on the pileus with more abundant inflated cells and a common presence of clamps. Our molecular analyses also indicate that A. subparvipantherina is a distinct species and it is probably related to A. parvipantherina, A. mellaialba and A. altipes, but their relationships lack significant statistical supports.
Fig. 1 Phylogram of Amanita subparvipantherina from Maximum likelihood (RAxML) analysis of LSU, rpb2 and tef1-α sequence data. Maximum likelihood bootstrap values greater than 50 % and Bayesian posterior probabilities over 0.90 are indicated above or below the nodes.