Phallus lutescens T.H. Li, T. Li & W.Q. Deng, 2020

Li, Ting, Li, Taihui, Deng, Wangqiu, Song, Bin, Deng, Chunying & Yang, Zhu L., 2020, Phallus dongsun and P. lutescens, two new species of Phallaceae (Basidiomycota) from China, Phytotaxa 443 (1), pp. 19-37 : 30

Phallus lutescens T.H. Li, T. Li & W.Q. Deng , sp. nov. Figs. 5 , 7–8

MycoBank ID: MB831827

Diagnosis:— Phallus lutescens is similar to P. luteus , but differs in a cream white indusium which can turn to yellow or orange yellow when mature or dried, a white to weakly pinkish volva and narrower basidiospores (3.0–4.3 × 1.1–1.8 μm).

Etymology:— “ lutescens ” means turning yellow, referring to the indusium colour which turns from white to yellow when mature or dried.

Typification:— CHINA. Guangdong Province, Guangzhou City, South China Botanical Garden, at 113°21′55′′ E, 23°11′23′′ N, 23 m alt., 15 Jun. 2018, coll. by Ming Zhang & Wangqiu Deng (Holotype, GDGM 72218).

Description:— Mature basidiomata up to 130 mm high. Receptacle subovoid to campanulate, 15–20 mm high, 16–23 mm broad, obviously densely reticulated with irregular ridges and irregularly polygonal meshes, often covered with olive brown gleba, yellowish white (1A2) to pale yellow (2A3) or light yellow (2A4) under gleba, margin pendent to slightly upturned, with a prominent perforate pore 2–3.5 mm in diam. at the truncate apex. Gleba olive brown (4E4–8, 4F3–8), mucilaginous. Pseudostipe cylindrical, usually tapered upwards and enlarged downwards, 70–90 mm high, 9–11/13–17/ 20–23 mm thick (apex/middle/base), snow white (1A1), to very weak cream white, fragile and soft, spongiform, hollow; pseudostipe wall 1.5–3 mm thick, usually consisting of two layers of small chambers. Indusium latticed, white, yellowish white (1A2) to pale yellow (3A3) when young and fresh, becoming light yellow (4A4) to deep yellow (4A7) when mature or dried, expanded to 2/3–5/6 portion of pseudostipe, rarely reaching ground. Apertures of indusium usually polygonal, 3–6 mm broad. Volva globose or slightly obovate, 25–35 mm high, 22–30 mm broad, smooth or lightly rugose, dull white (4A1–2) to yellowish grey (4B2) or pinkish white (7B2–10A2), more often pinkish white (10A2) at base. Rhizomorphs simple to branched, dull white (4A1) to pinkish white (7A2–10A2), 1–3 mm thick. Odour foetid (mainly from gleba). Taste mild.

Basidiospores cylindrical to long ellipsoid, [80/4/4](3.0–)3.2–3.8(–4.3)× (1.1–)1.3–1.6(–1.8) μm, Q= (2.00–)2.19– 2.46 (–2.71), Qm = 2.35 ± 0.15, hyaline and light olivaceous in H 2 O and 5% KOH solution, inamyloid, thin-walled, smooth under the light microscope, slightly truncate at one end under the SEM. Hyphae of receptacle, pseudostipe and indusium hyaline, thin-walled, pseudoparenchymatic, consisting of globose to subglobose or irregularly globose structures, up to 45 μm in diam. Hyphae of volva tubular and branched, 2.5–10 μm in diam., thin-walled, smooth, septate, with clamp-connections. Hyphae of rhizomorph filamentous, 2.5–7.0 μm in diam., thin-walled, smooth, septate, rarely branched.

Known distribution:—So far, known only from subtropical areas of Guangdong Province in southern China.

Habit and habitat:—Solitary on soil with decaying litter under broad-leaved trees dominated by Melaleuca cajuputi subsp. cumingiana (Turcz.) Barlow and Saraca dives Pierre ; Season: April to June.

Additional specimens examined:— CHINA. Guangdong Province, Guangzhou, South China Botanical Garden , at 113°21′40′′ E, 23°10′51′′ N, 27 m alt., 5 May 2018, coll. by Ming Zhang ( GDGM 71306 ) ; Guangdong Province, Jiangmen, Xiachuandao island , at 112°37′39′′ E, 21°41′45′′ N, 40 m alt., 27 April 2013, coll. by Shihao Zhou & Jiang Xu ( GDGM 49991 ) ; Zhongshan, Shumuyuan Park , at 113°22′12′′ E, 22°29′21′′ N, 60 m alt., 25 April 2019, coll. by Hongmei Sun & Panpan Liu ( GDGM 76604 ) .

Figures

FIGURE 5. Basidiomata of Phallus lutescens from fresh to dried (a–d). a: GDGM 49991. b: GDGM 72218 (holotype). c: GDGM 76604. d: Sections of GDGM 72218 (holotype). Scale bars: a–d = 20 mm. Photos by Ming Zhang and Ting Li.

FIGURE 7. Microscopic features of Phallus dongsun (GDGM 75402, holotype), P. impudicus (GDGM 77656) and P. lutescens (GDGM 72218, holotype) under light microscope. a–c: Microscopic features of P. dongsun. d–f: Microscopic features of Phallus impudicus. g–i: Microscopic features of Phallus lutescens. a, d, g: Pseudoparenchymatous hyphae from the indusium. b, e, h: Basidiospores. c, f, i: Hyphae from the volva. Scale bars: a–i = 10 µm. Sections of structures a, c, d, f, g and i were mounted in Congo Red mixed with the 5% KOH. Photos by Ting Li.

FIGURE 8. Basidiospores under scanning electron microscope. a, b: Phallus dongsun (GDGM 75402, holotype). c, d: P. impudicus (GDGM 77656). e, f: P. lutescens (GDGM 72218, holotype). Scale bars: a, d, e = 5 µm, b = 2 µm, c = 20 µm, f = 3 µm. Photos by Ting Li.