Conocybe serrata T. Bau & J. Liu, 2018

Liu, Jing & Bau, Tolgor, 2018, New species and new records in the genus Conocybe (Bolbitaceae) from China, Phytotaxa 357 (4), pp. 261-274 : 267

Conocybe serrata T. Bau & J. Liu sp. nov. Fig. 4 , 7B

MycoBank MB 823261

—Etymology:—referring to the serratus veil on the pileus.

Diagnosis:— Conocybe serrata is distinguished by serrate appendicular on the pileus, broadly ellipsoid basidiospores with indistinctive germ-pore, and lageniform with neck cheilocystidia.

Type:— CHINA. Jilin Province: Changchun city, Jilin Agricultural University (43° 48′ 248″ N, 125° 24′ 28″ E), September 5 th 2016, Tolgor Bau & Jing Liu, HMJAU42442 (Holotype!) ; same location, September 8 th 2016, Jing Liu HMJAU42443 (Isotype) .

Description:—Pileus 7–25 mm broad, campanulate to conico-convex then plano-convex to almost applanate with a slight umbo, hygrophanous, reddish brown when moist and young, copper (red), Venetian red, brownish red, mixed with ochre brown in centere (7A7–B7, 7C7–C8, 8D7,8D8, 9D7), slightly paler towards margin, orange to brownish orange (6B6, 6C8), translucent striate, on drying salmon, light orange or pale ochraceous (6A4–A5), smooth; margin appendiculate veil firstly serratus with fugacious triangular flocks, white to yellowish, easily detachable. Context concolorous with the surface. Odor and taste not distinctive. Lamellae 2–4 mm broad, adnexed to adnate, yellow-brown to orange-brown with whitish floccose edge, rather crowded with three series of lamelluae, ventricose. Stipe 23–60 × 1–2.5 mm, cylindrical, solid to hollow, covering with white-floccose squammules, pruinose at apex, without velar remnants, whitish at first, then yellow brown, ochre-yellow, becoming paler in age on upwards.

Spores (7.3–)7.7–9.3(–9.7) × (3.8–)4.1–4.7(–4.9) μm, Q=(1.6)1.66–1.9(2.0), Q m =1.83±0.1, ellipsoid-oblong, slightly thick-walled, germ pore absent, ochre-brown to rust brown in ammonia. Basidia 17–24 × 7–12 μm, clavate, 4- spored. Cheilocystidia 24 –42 × 7 –12 μm, predominantly lageniform with obtusely short broad neck, in addition some clavate elements. Pleurocystidia absent. Lamellae trama is parallel, consisting of cylindrical to inflatened hyphae 2.5– 30 μm broad, hyaline to pale ochraceous brown. Stipitipellis a cutis made up of cylindrical hyphae 2.5–7 μm broad, hyaline to pale ochraceous thin-walled. Caulocystidia 35–67 × 7.0–15 μm, similar to cheilocystidia, predominantly lageniform with larger and irregular short or tapering neck, occasionally subcapitate, mixed with subcylindrical slightly tortuous clavate cells. Pileipellis an epithelioid hymeniderm, consists of clavate and spheropedunculate cells, 22–49 × 15–22 μm, in part with thickened, brown walls. Pileocystidia not seen. Clamp connections present.

Habit and habitat:—Saprotrophic, solitary or in small groups, on fertile grasslands, or in the margin of deciduous forests.

Distribution:— China.

Note:— Conocybe serrata is similar to C. vestita (Fr.) Kühner as they both have remained veil on the pileus margin and the similar color. It is easy to distinguish them, macroscopically, Prydiuk reported that Conocybe vestita is distinguished by fugacious ring-like white floccules of veil in upper part of stipe, while veils on the stipe of Conocybe serrata is white-floccose squammules ( Prydiuk 2006). Microscopically, basidiospores of C. vestita are smaller, 6.0–8.5 × 3.5–5.0(5.5) μm, and cheilocystidia of C. vestita is predominantly subcylindrical (Arnolds 2005).

Conocybe aporos Kits van Wav. and C. dentatomarginata = Pholiotina nemoralis (Harmaja) M.Bon var. dentatomarginata (Watling) Hauskn. are in the same clade (clade D) with the new species C. serrata , which maybe on account of partial appendicular veils on the pileus and non-lecythiform cheilocystidia (Hausknecht et al. 2007).

Conocybe serrata is grouped together with C. aporos in the phylogenetic analyses for indistinct germ pore, but the latter species is easy to distinguish by annulus on stipe in the field.

Morphologically, C. serrata is limited by serrated appendicular veil on pileus and indistinctive germ pore, pileus veil remnants of C. dentatomarginata are not so abundant as C. seratta . Differences in cystidia are also easily to distinguish those two species, C. seratta is characterized by predominantly lageniform with obtusely short broad neck mixed with some clavate elements, while C. dentatomarginata is distinguished by cylindrical to cylindrical-capitate cystidia (Hausknecht et al. 2007). Plus, distinct germ pore of C. dentatomarginata is an obvious evidence to separate them, C. dentatomarginata have lager basidiopores 10.8–13.0 × 5.7–7.0 μm (Malysheva 2011) compared with C. serrata .

Conocybe serrata is proposed in the Conocybe genus by hygrophanous pileus and remnants veils on pileus, as well as brown spores. Microscopical feature of non-lecithyform cystidia is due to this species is closer to ancestral cystidia, and not evolve many times in the Bolbitiaceae ( Tóth et al. 2013) .

Figures

FIGURE 4. Conocybe serrata HMJAU42442A) Basidiomata B) Basidiospores C) Basidia D)Cheilocystidia E)Caulocystidia F) Pileipellis Bars:A=1cm; B—F=10 μm. Illustration by Jing Liu.

FIGURE 7. A) Conoybe cylindrospora (HMJAU42440) B) Conocybe serrata (HMJAU42442). C) Conocybe fuscimarginata (HMJAU42438) D)Pholiotina vexans (HMJAU42439) Bars: a and d=10 mm. photo a–b by Yu-peng Ge; photo c and d by Tolgor Bau.