Tetrapyrgos subcinerea (Berk. & Broome) E. Horak, Sydowia

Honan, Amy H., Desjardin, Dennis E., Perry, Brian A., Horak, Egon & Baroni, Timothy J., 2015, Towards a better understanding of Tetrapyrgos (Basidiomycota, Agaricales): new species, type studies, and phylogenetic inferences, Phytotaxa 231 (2), pp. 101-132 : 115-117

Tetrapyrgos subcinerea (Berk. & Broome) E. Horak, Sydowia 39: 103. 1987 [1986]. Fig. 6a–h

Basionym: Marasmius subcinereus Berk. & Broome, J. Linn. Soc. Bot. 14: 37. 1875 (1873).

Synonyms: Chamaeceras subcinereus (Berk. & Broome) Kuntze, Revis Gen. Pl. (Leipzig) 3(2): 457. 1898.

Marasmiellus nigripes var. subcinereus (Berk. & Broome) Pegler, Persoonia 4: 110. 1966.

Marasmiellus subcinereus (Berk. & Broome) Pegler, Kew Bull., Addit. Ser. 6: 117. 1977.

Pterospora subcinerea (Berk. & Broome) E. Horak, Sydowia 36: 136. 1983.

Marasmius nigripes var. albus Corner, Beih. Nova Hedwigia 111: 75. 1996.

Marasmius nigripes var. fuscibrunneus Corner, Beih. Nova Hedwigia 111: 75. 1996.

Holotype:— SRI LANKA. Peradeniya , September 1868, GHK Thwaites 782 (K!).

The holotype specimen consists of 14 intact basidiomes, 13 of them attached to fragments of leaves or small twigs, glued to a card, in fair condition. All are overgrown by several molds.

Description of dried holotype: Pileus convex, striate, creamy brown. Lamellae adnate with a short decurrent tooth, relatively broad, cream. Stipe central, relatively long, covered with a white pruina, dark brown overall, non-insititious, arising from a flattened, circular pad of radiating brown mycelium.

Micromorphological analysis of the holotype: Basidiospores only 3 seen, 9.5–10.2 × 8.3–9.5 μm, tetrahedral to triangular in side view, hyaline, inamyloid, thin-walled. Basidioles clavate, clamped. Lamellar edges collapsed and reviving poorly; cheilocystidia few seen, similar to the caulocystidia (see below). Pleurocystidia absent. Pileipellis a loosely arranged Rameales -structure of diverticulate hyphae, non-gelatinized, non-incrusted, hyaline, thin-walled, clamped; badly parasitized. Stipe cortical hyphae parallel, cylindrical, 2.5–6 μm diam., smooth, with olivaceous plasmatic pigments, giving rise to numerous clustered caulocystidia. Caulocystidia 22–32 × 5–8 μm, irregular in outline to cylindrical, often lobate, coarsely diverticulate, hyaline, thin-walled.

Description based on newly collected specimens: Pileus 1–17 (–27) mm diam., hemispherical or convex, occasionally with a central papilla when young, remaining convex or becoming plano-convex or sometimes applanate and occasionally depressed to umbilicate in age, striate to rivulose; surface dull, dry, finely pubescent overall, white when young, occasionally remaining white through development, more often with disc becoming grey (1A1) to bluish grey (23E2) or dark brown (6F5) in age, margin white to cream, staining blue grey (23E2) or greyish brown (7D2) in age. Context in pileus 0.5 mm thick, concolorous with surface. Lamellae adnate to decurrent, close to subdistant with 2–5 series of lamellulae, shallowly to broadly intervenose and anastomozing, white, sometimes becoming cream or staining grey in age. Stipe 1–17 (–34) × 0.3–0.8 mm, central, occasionally eccentric, terete or with a flared apex and gradually narrowed downward, subinsititious from a flattened circular pad of grey appressed mycelium, dull, dry, twisted fibrous, appressed-fibrillose and covered with pruinae; apex white, base becoming black or bluish black (19F8). Odor and taste not distinctive.

Basidiospores 6.4–12.4 (–13.6) × (4.8–) 6.4–10 (–12.8) μm [x mr = 7.1–11.6 × 6.1–10.3 μm, x mm = 9.8 ± 1.01 × 8.3 ± 0.98 μm, Q = 0.9–1.6, Q mr = 1.1–1.3, Q mm = 1.2 ± 0.05, n = 5–20, s = 44], tetrahedral, hyaline, inamyloid, thin-walled. Basidia 21–27 × 6–8 μm, 4-spored, hyaline, inamyloid, thin-walled, clamped. Basidioles 20–28 x 3.5–6 μm,

subfusoid to subclavate, hyaline, inamyloid, thin-walled. Pleurocystidia absent. Cheilocystidia 16–46 × 3.2–7.2 (–9)

μm; apex most often bulbous and smooth, often branched, occasionally diverticulate, hyaline, inamyloid, thin-walled;

central axis diverticulate; diverticula 0.8–5.6 (–7.2) × 0.8–4 μm, cylindrical or knob-like, occasionally branched or acute. Pileipellis a Rameales -structure of loosely interwoven, strongly diverticulate hyphae 2.2–8.4 μm diam; terminal cells 15–44 × 3.2–5.6 (–7.2) μm, often branched, diverticulate, hyaline or occasionally with yellowish brown contents that wash out in KOH, inamyloid, thin-walled; diverticula 0.8–6.5 × 0.8–3 μm, cylindrical or knob-like, seldom branched. Stipe tissue monomitic; cortical hyphae 3.2–8.8 μm diam., parallel, cylindrical, hyaline to yellowish brown, inamyloid, thin-walled, with scattered diverticula; medullary hyphae hyaline. Caulocystidia 24–36 × 3.2–6.4 μm, branched, densely diverticulate, with or without bulbous apices, similar to cheilocystidia. Clamp connections present.

Habitat and known distribution: Solitary to gregarious on decaying leaves and twigs. Indonesia, Kenya, Malaysia, Papua New Guinea, Sri Lanka, Thailand, Uganda, United States (Hawaiian Islands).

Material examined:— INDONESIA. Bali: Pasar Desa Belimbing, temple south of Sanda , 16 January 1999, A Retnowati 138 (BO, SFSU) ; Java: Mt. Halimun National Park, trail from Cikaniki , 13 January 1998, A Retnowati 019 (BO, SFSU) ; Java: Jepara District, Karimunjawa subdistrict, Karimunjawa Village , Kampung Alag-alang , Lagon Lele, no date recorded, A Retnowati 505 (BO, SFSU) ; Java: Bogor Botanical Gardens , elev. 266 m, S06º 35.955’, E106º 47.720’, 8 January 2000, DE Desjardin 7073 (BO, SFSU) ; same location, 15 January 2005, AH Honan 109 ( SFSU) ; Java: Lido, S. side of Gede-Pangrango National Park, Bedogol Research and Conservation Education Center , elev. 800 m, 17 January 2005, AH Honan 115 ( SFSU) ; Lombok: Suranadi, 26 January 2001, E Horak 9175 (ZT). KENYA. Central Province : Nairobi District , Nairobi , City Park , 6 April 1968, DN Pegler 376 (K). MALAYSIA. Selangor: Kuala Lumpur, Gombok Field Station , elev. 240 m, N 03º91.50’, E 101º 45.167’, 12 January 2003, DE Desjardin 7517 ( SFSU) ; same location, 5 January 2005, AH Honan 82 ( SFSU) ; Selangor: Hulu Langat, Sungai Chongkak Forest Reserve , elev. 188 m, N 03º 12.705’, E 101º 50.472’, 7 January 2005, AH Honan 86, AH Honan 88, AH Honan 89, AH Honan 90 ( SFSU) ; Selangor: Selayang, Kanching Forest Reserve , elev. 110 m, N 03º 17.954’, E 101º 37.153’, 9 January 2005, AH Honan 93, AH Honan 96 ( SFSU) ; Selangor: UMFSC, 16 October 2004, Y-S Tan TYS363 ( SFSU) ; Negeri Sembilan: Ulu Bendul Forest Reserve , 23 October 2004 ; Y-S Tan TYS379 ( SFSU) ; same location, 24 October 2004, Y-S Tan TYS380 ( SFSU) ; Negeri Sembilan: Kuala Pitah, Ulu Bendon Recreation Area , 6 January 2005, AH Honan 84 ( SFSU) ; Langkawi Island : January 2005, KUM60047 and KUM60051 ( SFSU) ; Langkawi Island: Matchinchang , 1 September 2004, Y-S Tan TYS347 ( SFSU) ; Pahang: Fraser’s Hill, Jalan Genting south to Fraser’s Hill , elev. 1320– 1138 m, 15 January 2004, AH Honan 17 ( SFSU). PAPUA NEW GUINEA. Morobe District: Bulolo , 2 February 1972, E Horak 72-120 (ZT) ; Eastern Highlands: Mt. Michael, Lufa , 31 July 1972, E Horak 72-549 (ZT) ; Madang: Silibob , elev. 100 m, S05º12’, E145º45’, 29 January 1997, R Walleyn 779 ( GENT) ; Madang: Baitabag, Kua Wildlife Area, elev. 170 m, S05º09’, E145º06’, R Walleyn 832 ( GENT). SRI LANKA. Peradeniya , September 1868, Thwaites 782 (K, holotype). THAILAND. Mae Hong Son Province: Ma Sa Kut Luang Waterfall, approx. 4 km south of Mae Hong Son, elev. 300 m, 29 June 2002, DE Desjardin 7416 ( SFSU) ; Chiang Mai Province: Mok Fa Waterfall on Hwy 1095, elev. 1014 m, 28 June 2003, DE Desjardin 7585 ( SFSU) ; Chiang Mai Province: Doi Suthep National Park, across from Sangasabhasri Lane , N18º 48.62’, E 98º 54.60’, 6 July 2004, AH Honan 70, AH Honan 71, AH Honan 72 ( SFSU) ; Chiang Mai Province: Doi Suthep National Park, Mok Thaton Waterfall , elev. 1120 m, 3 July 2002, DE Desjardin 7448 ( SFSU) ; same location, 6 July 2004, AH Honan 73 ( SFSU) ; same location, 7 July 2004, AH Honan 75 ( SFSU) ; Chiang Mai Province: New Waterfall, 36 km on Hwy 1095, 2 July 2004, AH Honan 52 ( SFSU) ; Chiang Mai Province: Mae Sae Village, near 50 km marker on Hwy 1095, elev. 962 m, N19º 14.599’, E 98º 38.456’, 26 June 2005, AH Honan 129, AH Honan 134 ( SFSU). UGANDA. Buganda Province: Mengo District, Mabira Forest , 9 June 1968, DN Pegler U 1366 (K). UNITED STATES. Hawaii: Kaua’i Island , Alaka’i Wilderness Preserve, Mohihi-Wai’alae Trail, between N 22º07.204’, W159º36.229’ and N22º06.860’, W159º35.034’, elev. 1219 m, 6 January 1995, DE Desjardin 6178 ( SFSU) .

Commentary: Tetrapyrgos subcinerea has been accepted as a distinct species ( Pegler 1977, Horak 1983, 1987) or as a synonym of T. nigripes ( Pegler 1966, 1983, 1986, Singer 1973). ITS sequence data ( Fig. 1 ) distinguish 19 Southeast Asian specimens, herein referred to T. subcinerea , in a monophyletic clade with 93% PP support distinct from several New World specimens attributed to T. nigripes . While macromorphological differences exist in our collections from Southeast Asia (in basidiome size, pileus and stipe pigmentation, substrate), microscopically they cannot be differentiated. Cystidia and basidiospore shapes are indistinguishable amongst specimens, and their sizes are variable and overlapping in all collections. There appears to be some phylogenetic differences among the specimens as two distinct internal clades were consistently resolved with 95% and 99% PP support. However, species with identical morphologies and from the same sites fall into different internal clades, (e.g.: AHH 134 and 129; KUM 60051 and 60047). Further analyses of the ITS region to evaluate the presence of non-homologous copies, and sequences of additional genes are necessary to delineate these collections. Based on micromorphology and the current ITS sequence data available, we accept these specimens as representing an Old World species complex with the available name T. subcinerea . DNA extraction of the African and Sri Lankan material was not permitted and new collections from these regions are necessary to clarify the phylogenetic relationships among paleotropical populations. Marasmius nigripes var. albus and Marasmius nigripes var. fuscibrunneus , both described from the Singapore Botanic Gardens, are herein accepted as synonyms of T. subcinerea (see type studies below).

Figures

FIGURE 1. Maximum likelihood (-lnL = 3590.75887) topology of Tetrapyrgos specimens sampled as part of this investigation based on ITS sequence data. Numbers separated by “/” represent non-parametric maximum likelihood bootstrap (BS) proportions and Bayesian posterior probablilites (PP), respectively. Branches highlighted in bold received combined support values of ≥70%/0.95.

FIGURE 6. Macroscopic and anatomical features for Tetrapyrgos subcinerea (DED 7517 a–b, d–g; Thwaites 782—Holotype c, h). a. Basidiomes. b–c. Basidiospores. d. Basidium and basidioles. e. Cheilocystidia. f. Pileipellis terminal cells. g–h. Caulocystidia. Scale bars: a = 10 mm, b–h = 10 μm. Illustrated by D.E. Desjardin.