Phallus rigidiindusiatus T. Li, T.H. Li & W.Q. Deng sp. nov.

Figures 4, 5d-f

Diagnosis.

Characterized by a well-developed indusium with thick meshes, morphologically similar to Phallus serratus, but different in its rigid, round or irregular meshes of indusium without serrated margin, and in smaller basidiospores.

Holotype. China. Guangdong Province, Jiangmen City, Yunkaishan National Nature Reserve. (22°17'57"N, 111°12'37"E, alt. 1350 m), Song Bin and Wen Huashu,10 June 2020 (GDGM 81196).

Immature basidioma globose to subglobose, 55-65 × 50-57 mm, white (1A1), slightly yellowish white (4A2) to orange white (7A2) or pinkish white (10A2), partially darker to grayish brown (7D3), smooth, attached to substrate by grayish violet (17D5-7) rhizomorphs. Exoperidium membranous; endoperidium gelatinous, hyaline. Expanded basidioma big-sized, 220-240 mm high when fresh. Receptacle 40-50 mm high, 50-60 mm broad, campanulate to subconical, white (1A1) to yellowish white (3A2), reticulated with irregularly ridges up to 4.5 mm deep, covered with gleba; apex truncate, perforated, or with a white spongy expansion up to 8 mm high, 10 mm in diam. Gleba yellowish brown to linoleum brown (5E5-7), mucilaginous. Pseudostipe subcylindrical, constricted at apex, enlarged toward base, white (1A1), spongiform, hollow, 170-190 mm high, 15-20/28-35/35-40 mm broad (apex/middle/base); pseudostipe wall 5-9 mm thick, usually consisting of small irregular chambers in 1-3 mm width. Volva obovate, 55-65 mm high, 50-60 mm broad, smooth, brownish orange (7C6) to light brown (7D8). Indusium well-developed, expanded to 3/4-5/6 portion of pseudostipe, white, up to 170 mm in length, attached to apex of pseudostipe, with rigid polygonal to irregular meshes becoming gradually smaller from top to bottom, margin entire; meshes usually not serrated at margin, 5-20 mm wide, up to 7 mm thick. Rhizomorphs simple, grayish orange (6C5) to brown (7E4), up to 3 mm thick, 4 cm long. Odour foetid (mainly from gleba). Taste mild.

Basidiospores (3.5-)3.7-4.2(-4.5) × 1.6-2.0(-2.3) μm, Q= (1.7-)2.1-2.4 (-2.6), Qm= 2.3 ± 0.2, cylindrical to long ellipsoid, hyaline and light olivaceous in H2O and 5% KOH solution, inamyloid, thin-walled, smooth, truncate at one end under light microscope. Hyphae of receptacle, pseudostipe and indusium hyaline, thin-walled, pseudoparenchymatic, consisting of globose to subglobose or irregularly globose structures, up to 25 μm in diam. Hyphae of volva tubular and branched, 3-5 μm in diam., thin-walled, smooth, septate, with clamp-connections. Hyphae of rhizomorphs filamentous, up to 6.0 μm in diam., thin-walled, smooth, septate, rarely branched.

Habitat and distribution.

Solitary or scattered on soil with decaying litter in forests dominated by broad-leaved trees and bamboo groves. So far known only from southern China and southwestern China (Guizhou). Season: May to June.

Etymology.

With reference to the rigid indusium.

Additional specimens examined.

China. Hunan Province, Rucheng County, Jiulongjiang National Forest Park (25°26'49"N, 113°48'10"E, alt. 555 m), Huang Hao, 7 May 2015 (GDGM 54237) ; Guizhou Province, Duyun County, Doupengshan scenic place (26°21'17"N, 107°22'49"E, alt. 1300 m), Deng Chunying, 16 May 2020 (Dcy 2517) ; Guangdong Province, Shaoguan City, Nanling National Nature Reserve (24°49'54"N, 113°7'22"E, alt. 994 m), Song Bin and Xie Dechun, 27 May 2021 (GDGM 85470) ; Guangdong Province, Jiangmen City, Yunkaishan National Nature Reserve. (22°15'22"N, 111°9'23"E, alt. 1480 m), Song Bin and Wen Huashu, 10 June 2020 (GDGM 81179) ; Guangdong Province, Jiangmen City, Yunkaishan National Nature Reserve. (22°17'58"N, 111°12'36"E, alt. 1420 m), Song Bin and Wen Huashu, 10 June 2020 (GDGM 81195) .