Lepiota pallidovelata X. Li & J. F. Liang sp. nov.

Fig. 2

Holotype.

China • Jilin: Changchun City, Jinyuetan Park, 8 Jul 2004, J. R. Wang (holotype, HMJAU 3547). GenBank: ITS = MK 651643; LSU = MK 651684; rpb 2 = PX 913186; mtSSU = MK 651732.

Etymology.

pallidovelata (Latin), referring to the distinctive pale (whitish to light brown) squamules on the pileus and the persistent veil remnants at its margin.

Diagnosis.

Lepiota pallidovelata is characterized by its small basidiomata, pileus with whitish to light brown squamules and veil remnants at the margin, penguin-shaped basidiospores with a suprahilar depression, clavate cheilocystidia, pileus covering a trichoderm composed of long elements (sometimes narrowing towards the apex) and a layer of short elements at their base.

Sectional placement.

Lepiota sect. Lepiota.

Description.

Basidiomata small (Fig. 2 A). Pileus 1.5–2.5 cm in diam, initially campanulate, becoming convex, with a blunt, light brown to brown (6 B 3–6 B 5) umbo; around the umbo, the surface breaks up into concentric, felted patches to fibrillose squamules on whitish background; squamules becoming smaller and sparser towards the margin, whitish to light brown (6 A 2–6 A 4); margin exceeding lamellae, with whitish and fibrillose veil remnants. Context whitish, thin to slightly thick. Lamellae L = 40–60, l = 1–2, free, whitish, moderately to densely crowded, ventricose; lamella edge even. Stipe 2.5–6 × 0.2–0.4 cm, subcylindrical, hollow, narrow to apex, slightly thickened at the base, light brown to brown (5 B 3–5 B 4), nearly smooth above the annular zone, lower down with distinct lanate annular zone, below which covered with dense, whitish and floccose squamules. Smell and taste not recorded. Spore print whitish.

Basidiospores (Fig. 2 B) [80 / 4 / 4] (8.0) 9.0–11.5 (12.0) × 3.5–5.0 (5.5) μm [Q = (2.00) 2.10–2.88 (3.14), Q av = 2.51 ± 0.26], penguin-shaped in side view, with suprahilar depression; adaxial side slightly convex; abaxial side nearly straight or sometimes slightly constricted; fusiform in front view; colorless, hyaline, smooth, slightly thick-walled, weakly dextrinoid, congophilous, not metachromatic in cresyl blue; apiculus tiny. Basidia 23–28 × 8–13 µm, clavate, 4 - spored. Cheilocystidia (Fig. 2 D) 12–26 × 5–9 μm, clavate, colorless, hyaline, thin-walled. Pleurocystidia absent. Pileus covering (Fig. 2 C) a trichoderm composed of subcylindrical, sometimes narrow to apex, terminal elements 58–210 × 6–12 µm rarely bearing septa without clamp connections located in the middle to upper parts, with short and clavate elements at base that contain yellow-brownish intracellular pigment. Clamp connections present in all tissues.

Distribution.

(abbreviation: dist., below). Currently found in Jilin, Yunnan Province, and Beijing City, China.

Habitat.

Solitary, saprotrophic on decaying wood and leaf litter. The specimen from Yunnan was found on a decayed branch covered with the vine Tetrastigma triphyllum and pine needles, indicating occurrence in a disturbed or forest-edge habitat. Its presence across temperate (Jilin, Beijing) to subtropical (Kunming, ca. 1900 m a. s. l.) mixed forests suggests broad environmental tolerance, potentially including adaptability to secondary environments.

Additional specimens examined (paratypes).

China • Jilin: Changchun City, Jinyuetan Park, 13 Jul 2004, J. R. Wang (HMJAU 3533); • Beijing: Huairou County, Hongluo Temple, old-growth forest, 25 Aug 2000, T. Bau (HMJAU 1310); • Yunnan: Kunming, Kunming Institute of Botany, 1 Aug 2007, Yang 4797 (HKAS 52312).

Nomenclatural note.

The epithet ‘ submagnispora’ was provisionally registered in MycoBank (no. 860343). Following critical review, it is here formally amended to ‘ pallidovelata ’ to more accurately reflect the diagnostic morphological features (i. e., the whitish squamules on the pileus with veil remnants).

Notes.

Lepiota pallidovelata is distinguished by its tiny basidiomata; blunt and light brown to brown umbonate pileus with whitish to light brown squamules and veil remnants at the margin; penguin-shaped basidiospores without a narrow apex; clavate cheilocystidia; and pileus covering a trichoderm composed of terminal elements, sometimes narrowing toward apex, and basal short elements.

Phylogenetic analysis recovers L. pallidovelata as sister to L. attenuata Jun F. Liang & Zhu L. Yang with strong support. Both species share the characteristic penguin-shaped basidiospores and a trichodermal pileus covering. They are readily separable morphologically. Lepiota attenuata (dist., China: Yunnan) differs in its larger basidiomata, densely covered with brownish yellow to yellowish brown squamules on a whitish background, prominently striate pileus margin, and longer basidiospores that narrow toward the apex (Liang et al. 2011).

Several Lepiota species share the penguin-shaped basidiospores and trichodermal pileus covering but can be distinguished from L. pallidovelata by distinct morphological features. Lepiota magnispora Murrill (dist., North America, Europe, and Asia) differs in having larger basidiomata, longer basidiospores (Q av = 3.29), and more diverse cheilocystidia (Liang 2007; Yang et al. 2019). Lepiota thrombophora (Berk. & Broome) Sacc. (dist., Sri Lanka; China: Yunnan, Hainan) can be distinguished by reddish brown to dark brown squamules, a striate pileus margin, whitish annulus, longer basidiospores, and a pileus covering rarely with basal short elements (Berkeley and Broome 1871; Liang et al. 2011). Lepiota ampliocystidia Jun F. Liang (dist., China: Xizang) differs in its yellowish brown to dark brown squamules on a radially striate pileus margin, lack of veil remnants, whitish annulus, and more elongated basidiospores with a narrowed apex (Liang 2012).

Comparative analysis also reveals distinct morphological features distinguishing L. pallidovelata from other Lepiota taxa. Lepiota metulispora (Berk. & Broome) Sacc. (dist., Sri Lanka, India, and southern China, including Hunan and Hong Kong) differs from L. pallidovelata in its appressed, ochraceous buff squamules on a whitish background, striations on the margin of the pileus, stipe with a whitish annulus, longer basidiospores, and gradually narrowing terminal elements in the pileus covering (Liang et al. 2011). Moreover, L. squamulodiffracta Justo, Bizzi & Angelini (dist., Dominican Republic) is distinguished from L. pallidovelata by its larger basidiomata, brown to orange-brown squamules on the pileus with a striate margin, the absence of veil remnants, and longer basidiospores (Justo et al. 2015).

Additionally, L. cortinarius J. E. Lange (dist., Europe, North America, and Asia, including China: Henan, Sichuan, Yunnan, Xizang) can be distinguished from L. pallidovelata by its larger basidiomata, dense dark brown squamules, a distinctly cortinate pileus margin, diverse cheilocystidia, and a pileus covering with longer terminal elements (Lange 1915; Liang 2007).