Hysterangiales revisited: expanded phylogeny reveals new genera and two new suborders.

Hysterangiales (Phallomycetidae, Agaricomycetes, Basidiomycota) is a diverse, nearly cosmopolitan order of predominantly hypogeous, sequestrate, ectomycorrhizal fungi. Expanding on previously published phylogenies, we significantly increased sampling of Hysterangiales specimens, emphasizing representatives from Australia. Using protein-coding genes atp6 (adenosine triphosphate synthase subunit 6) and tef1 (translation elongation factor 1-á), we recovered 26 provisional novel genera, and corroborated existing genera and families. Further, two new suborders (Phallogastrineae subord. nov. and Hysterangineae subord. nov.) and a new family (Phallogastraceae fam. nov.) are described, and three new combinations made to Phallogaster. Aspects of classification and biogeography are presented.

INTRODUCTION

Hysterangiales (Phallomycetidae, Agaricomycetes, Basidio-mycota) was established in 2006 to accommodate a phylogenetically refined Hysterangiaceae and relatives (Hosaka ). Hysterangiales comprises a wide array of predominantly hypogeous, sequestrate, ectomycorrhizal fungi, but some taxa in the basal lineage (Phallogastraceae) are epigeous and non-mycorrhizal. Hysterangiales possess a range of unusual morphologies (Fig. 1), such as basidiomes with a powdery spore mass (and often with a sterile core) in the Mesophelliaceae (Trappe ), the gelatinized or cartilaginous gleba with translucent columella in Gallaceaceae and Hysterangiaceae, or the utricle-encased spores of many Mesophelliaceae and Hysterangiaceae (Castellano & Beever 1994; Fig. 2). Like many truffle-like fungi, Hysterangiales often have distinct odours, which attract small animals for spore dispersal via mycophagy (e.g. Fogel & Trappe 1978, Claridge & May 1994). The characteristics of being mostly hypogeous and nearly universally dependent on other organisms for dispersal, combined with their worldwide (excluding Antarctica) distribution and diversity, have led to the consideration of multiple biogeographic scenarios for Hysterangiales, ranging from ancient Pangaean vicariance to recent long-distance dispersal (Hosaka ).

Fig. 1.

Examples of a range of basidiome morphologies in Hysterangiales. A–C. Phallogastraceae A. "Gen. prov. 1" (AU, photo credit M. Castellano). B. Phallogaster (Trappea) phillipsii (photo credit N. Siegel). C. Phallogaster saccatus (photo credit D. Mitchell/B. Roody); D–F. Gallaceaceae. D. Austrogautieria sp. (NZ, photo credit K. Hosaka). E. Gallacea eburnea (photo credit N. Siegel). F. Gallacea scleroderma (photo credit N. Siegel); G–I. Hysterangiaceae. G. Aroramyces sp. (AU, photo credit M. Castellano). H. Hysterangium sp. (AU, photo credit Castellano). I. Hysterangium sp. (NZ, photo credit K. Hosaka); J–L. Mesophelliaceae. J. Chondrogaster sp. (photo credit M. Castellano). K. "Gen. prov. 3" (photo credit M. Castellano). L. Mesophellia sp. (photo credit D. Catcheside); M–O. Mesophelliaceae. M. Nothocastoreum cretaceum (photo credit D. Catcheside). N. Castoreum radicatum (photo credit M. Castellano). O. Gummiglobus pachythrix (photo credit M. Castellano). Scale bars = 10 mm.

Fig. 2.

Three spore types observed in Hysterangiales. A. Mesophellia brevispora (photo credit M. Castellano): smooth, no utricle. B. "Genus prov. 7" (photo credit N. Davoodian): ornamented, utricle present. C. Austrogautieria (photo credit T. Lebel): ribbed, no utricle. Scale bars = 10 μm.

Hysterangiales taxa are remarkably abundant and highly diverse in Australia (a major impetus for the present study), particularly the endemic family Mesophelliaceae. Ectomycorrhizal Myrtaceae and Nothofagaceae species are the primary symbionts of Hysterangiales in Australasia. Another impetus for the present study is that numerous novel Australasian Hysterangiales taxa yet to be formally described have been known for over a decade but generic boundaries were not strongly supported (Hosaka 2005, Hosaka , 2008). We expanded on previous work initiated by Hosaka , 2008 by sampling extensively from Australian specimens, which corroborated known genera (both formally described and provisional) and families, and elucidated additional provisional novel genera.

MATERIALS AND METHODS

Collections referred to in this study are housed at various fungaria including AD, ATH, BRI, OSC, and MEL. Collections were initially sorted into morphotaxa based on macro- and micro- characters, and a broad selection of material encompassing as many genera as possible were then sampled for molecular analyses. This included some material from non-Australasian taxa that had not previously been sampled, to better support previous taxonomic hypotheses. Thin sections of fungal tissue were mounted in KOH, Melzers’ reagent and occasionally Congo Red + KOH to examine peridium and glebal structure, and spore size, shape, presence of a utricle, and ornamentation. Imaging was completed using either an Olympus BX-52 microscope with DP-73 camera and measurement tools using Olympus cellSens standard (v. 1.16) or a Zeiss/Moticam 10 camera system.

Adenosine triphosphate synthase subunit 6 (atp6; mitochondrial) and translation elongation factor 1-á (tef1; nuclear) nucleotide sequence data for Hysterangiales available on GenBank were downloaded. Further, new atp6 and tef1 sequences were generated for 99 Hysterangiales specimens, as well as one specimen of Phallales and one specimen of Cantharellales to use as outgroup (Table 1). For these newly sequenced specimens, DNA was extracted from dried herbarium material with the E.Z.N.A. Forensic DNA Kit (Omega Bio-tek). A portion of the mitochondrial protein-coding gene atp6 was PCR amplified with ATP6-3 and ATP6-2 primers (Kretzer & Bruns 1999) using the following cycling protocol: 95 °C for 5 min; 8 cycles of 94 °C for 35 s, 37 °C for 55 s, 72 °C for 60 s; 35 cycles of 72 °C for 60 s, 94 °C for 35 s, 45 °C for 55 s; 72 °C for 2 min. A portion of the nuclear protein-coding gene tef1 was PCR amplified with EF1-983F and EF1-1567R, or EF1-1953R, primers (Rehner & Buckley 2005) using the following cycling protocol: 95 °C for 5 min; 10 cycles of 94 °C for 30 s, 65 °C for 60 s, 72 °C for 90 s; 30 cycles of 94 °C for 45 s, 55 °C for 60 s, 72 °C for 70 s; 72 °C for 5 min. Sanger sequencing was conducted in forward and reverse directions at the Australian Genome Research Facility (Melbourne, Victoria, Australia). Sequences are deposited in GenBank (Table 1).

Table 1

Tabulation of specimens and sequences used in this study. Clade names are from Fig. 3. Generic names (genus verbatim determination) without a species name (species verbatim determination) are based on field identification; collections with species names (species verbatim determination) were examined micromorphologically. Australian (AUS) States and Territories indicated by: WA (Western Australia), NT (Northern Territory), QLD (Queensland), NSW (New South Wales), VIC (Victoria), TAS (Tasmania), SA (South Australia). United States (USA) states indicated by: AZ (Arizona), CA (California), CO (Colorado), ID (Idaho), OR (Oregon). Other geographic areas indicated as follows: NZ (New Zealand), NEWCAL (New Caledonia), PNG (Papua New Guinea), BRZ (Brazil), MEX (Mexico), WNA (western North America), ENA (eastern North America), CHN (China), GUYANA (Guyana), SSA (southern South America), NSA (northern South America), ASIA (Asia), SEASIA (southeast Asia), SING (Singapore), THAI (Thailand), IND (India), EUR (Europe), COSTA (Costa Rica), ZIMB (Zimbabwe). Novel DNA sequences generated for this study are indicated by GenBank accessions in bold.

Clade	Genus verbatim determination	Species verbatim determination	Collector or Herbarium ID	Geography	ATP6	TEF1	Family	Suborder (Order)
Cantharellaceae	Cantharellus	sp.	TL2893	SA	MT828543	MW302303	Cantharellaceae	(Cantharellales)
Geastrum	Geastrum	fimbriatum	OSC60730	USA - OR	DQ218887	DQ219226	Geastraceae	(Geastrales)
	Geastrum	floriforme	OSC29328	USA - CO	DQ218769	DQ219227	Geastraceae	(Geastrales)
	Geastrum	fornicatum	MEL2087743	NSW	DQ218888	DQ219228	Geastraceae	(Geastrales)
	Geastrum	pectinatum	MEL2096557	VIC	DQ218889	DQ219229	Geastraceae	(Geastrales)
	Geastrum	recolligens	OSC41996	USA - ID	DQ218770	DQ219230	Geastraceae	(Geastrales)
Geastrum (Radiigera)	Radiigera	fuscogleba	OSC58979	—	DQ218896	DQ219234	Geastraceae	(Geastrales)
Gen. prov. 25 Lebel & Davoodian	Aroramyces	sp.	MEL2236309	WA	MW438321	MW302302	Trappeaceae	(Phallales)
Trappea	Trappea	darkeri	OSC65085	USA - OR	DQ218938	DQ219292	Trappeaceae	(Phallales)
Ileodictyon	Protubera [Ileodictyon]	canescens [gracile]	MEL2063471	WA	DQ218931	DQ219283	Clathraceae	(Phallales)
	Protubera [Ileodictyon]	canescens [gracile]	MEL2105035	VIC	DQ218932	DQ219284	Clathraceae	(Phallales)
Phallogaster	Trappea	pinyonensis	AHF530	WNA	DQ218884	DQ219221	Phallogastraceae	Phallogastrineae (Hysterangiales)
	Phallogaster	saccatus	T13202	ENA	DQ218882	DQ219217	Phallogastraceae	Phallogastrineae (Hysterangiales)
Gen. prov. 1 Hosaka	Protubera	sp.	T20068	AUS	DQ218883	DQ219220	Phallogastraceae	Phallogastrineae (Hysterangiales)
	Protubera	hautuensis	OSC59673	NZ	DQ218801	DQ219218	Phallogastraceae	Phallogastrineae (Hysterangiales)
Gen. prov. 24 Castellano & Hosaka	Austrogautieria	sp.	Beaton66	AUS	DQ218820	DQ219133	Gallaceaceae	Hysterangineae (Hysterangiales)
	Austrogautieria	sp.	OSC122637	NZ	DQ218819	DQ219132	Gallaceaceae	Hysterangineae (Hysterangiales)
	Austrogautieria	clelandii	OSC62178	VIC	DQ218816	DQ219126	Gallaceaceae	Hysterangineae (Hysterangiales)
	Austrogautieria	clelandii	OSC80012	VIC	DQ218817	DQ219127	Gallaceaceae	Hysterangineae (Hysterangiales)
Hallingea	Hallingea	purpurea	Garido418A	SSA	n/a	DQ219145	Gallaceaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	H1199	TAS	MW449866	MW302288	Gallaceaceae	Hysterangineae (Hysterangiales)
	indet.		T19862	VIC	MW048610	MW302289	Gallaceaceae	Hysterangineae (Hysterangiales)
Gen. prov. 21 Hosaka	Austrogautieria	sp.	H4096	QLD	MW417403	MW302309	Gallaceaceae	Hysterangineae (Hysterangiales)
	Chondrogaster	sp.	MEL2059688	VIC	MW048613	MW302306	Gallaceaceae	Hysterangineae (Hysterangiales)
	Chondrogaster	sp.	H4263	QLD	MW048615	MW302290	Gallaceaceae	Hysterangineae (Hysterangiales)
	Gallacea	sp.	Beever718	NZ	MW449882	MW302308	Gallaceaceae	Hysterangineae (Hysterangiales)
	Gallacea	sp.	OSC122813	AUS	DQ218829	DQ219144	Gallaceaceae	Hysterangineae (Hysterangiales)
	Gallacea	sp.	MEL2053228	VIC	MW048612	MW264846	Gallaceaceae	Hysterangineae (Hysterangiales)
	Gallacea	subalpina	MEL2236389	NSW	MW048614	MW302307	Gallaceaceae	Hysterangineae (Hysterangiales)
	Gallacea	subalpina	OSC80855	NSW	DQ218827	DQ219142	Gallaceaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	HO130161	TAS	MW438331	MW302304	Gallaceaceae	Hysterangineae (Hysterangiales)
	Mesophellia	sp.	HO130165	TAS	MW048611	MW302305	Gallaceaceae	Hysterangineae (Hysterangiales)
Gen. prov. 22 Castellano	Gallacea	sp.	OSC122728	NZ	DQ218828	DQ219143	Gallaceaceae	Hysterangineae (Hysterangiales)
	Gallacea	sp.	REB2364	NZ	DQ218825	DQ219140	Gallaceaceae	Hysterangineae (Hysterangiales)
	Gallacea	sp.	KHNZ04123	NZ	MW449865	MW302293	Gallaceaceae	Hysterangineae (Hysterangiales)
	Gallacea	eburnea	OSC59601	NZ	DQ218766	DQ219138	Gallaceaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	Beever536	NZ	MW417402	MW302291	Gallaceaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	KHNZ04117	NZ	MW438330	MW302292	Gallaceaceae	Hysterangineae (Hysterangiales)
	Protubera	nothofagi	OSC59699	NZ	AY574786	DQ219219	Gallaceaceae	Hysterangineae (Hysterangiales)
Gen. prov. 23 Hosaka	Austrogauteria	sp.	T24466	NSW	MW438326	MW302299	Gallaceaceae	Hysterangineae (Hysterangiales)
	Gallacea	sp.	T25038	NEWCAL	DQ218826	DQ219141	Gallaceaceae	Hysterangineae (Hysterangiales)
	Gallacea	dingleyae	OSC59606	NZ	DQ218824	DQ219137	Gallaceaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	H5277	TAS	MW048616	MW302294	Gallaceaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	SEA28	QLD	MW438329	MW302297	Gallaceaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	T13462	QLD	MW048617	MW302298	Gallaceaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	KandGBeaton	AUS	DQ218790	DQ219174	Gallaceaceae	Hysterangineae (Hysterangiales)
Austrogautieria	Austrogautieria	sp.	OSC80139	AUS	DQ218763	DQ219130	Gallaceaceae	Hysterangineae (Hysterangiales)
	Austrogautieria	sp.	OSC80140	AUS	DQ218764	DQ219131	Gallaceaceae	Hysterangineae (Hysterangiales)
	Austrogautieria	chlorospora	MEL2320844	SA	MW048618	MW302295	Gallaceaceae	Hysterangineae (Hysterangiales)
	Austrogautieria	chlorospora	OSC46596	AUS	DQ218761	DQ219125	Gallaceaceae	Hysterangineae (Hysterangiales)
	Austrogautieria	costata	MEL2320846	SA	MW438327	MW302296	Gallaceaceae	Hysterangineae (Hysterangiales)
	Austrogautieria	manjimupana	OSC55900	AUS	DQ218818	DQ219128	Gallaceaceae	Hysterangineae (Hysterangiales)
	Austrogautieria	manjimupana	OSC59545	AUS	DQ218762	DQ219129	Gallaceaceae	Hysterangineae (Hysterangiales)
Gallacea	Gallacea	scleroderma	OSC59621	NZ	AY574787	DQ219139	Gallaceaceae	Hysterangineae (Hysterangiales)
Gen. prov. 11 Hosaka	Hysterangium	sp.	H6404	TAS	MW417406	MW302282	Hysterangiaceae	Hysterangineae (Hysterangiales)
Gen. prov. 11 Hosaka	Hysterangium	sp.	Halling5741	SSA	DQ218781	DQ219158	Hysterangiaceae	Hysterangineae (Hysterangiales)
Gen. prov. 11 Hosaka	Hysterangium	sp.	T26347	SSA	DQ218873	DQ219204	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	T26367	SSA	DQ218874	DQ219205	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	OSC122836	AUS	DQ218865	DQ219196	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	T15545	NZ	DQ218837	DQ219161	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	H4123	AUS	DQ218845	DQ219176	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	H4749	AUS	DQ218861	DQ219192	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	H5057	AUS	DQ218862	DQ219193	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	H6105	AUS	DQ218864	DQ219195	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	MEL2078287	TAS	DQ218843	DQ219173	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	OSC122483	PNG	DQ218867	DQ219198	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	OSC122721	NZ	DQ218866	DQ219197	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	OSC59629	NZ	DQ218853	DQ219184	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	“irregular”	T6965	WA	MW438322	MW302283	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	“rhodocarpum”	T6889	WA	DQ218858	DQ219189	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	salmonaceum	Beaton33	AUS	DQ218785	DQ219165	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	spegazzinii	Singer3426	SSA	DQ218787	n/a	Hysterangiaceae	Hysterangineae (Hysterangiales)
Gen. prov. 12 Castellano	Hysterangium	sp.	OSC122857	WNA	DQ218851	DQ219182	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	OSC122860	ASIA	DQ218860	DQ219191	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	T17856	WNA	DQ218857	DQ219188	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	T591	ENA	DQ218840	DQ219170	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	epiroticum	T6116	EUR	DQ218779	DQ219155	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	fragile	Kers3971	—	DQ218780	DQ219156	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	separabile	OSC69030	WNA	DQ218786	DQ219166	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	youngii	OSC59645	NZ	DQ218789	DQ219169	Hysterangiaceae	Hysterangineae (Hysterangiales)
Gen. prov. 13 Castellano	Hysterangium	sp.	T3296	MEX	DQ218842	DQ219172	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	T4794	WNA	DQ218846	DQ219177	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	strobilus	T5285	ENA	DQ218788	DQ219168	Hysterangiaceae	Hysterangineae (Hysterangiales)
Gen. prov. 14 Lebel	Aroramyces	sp.	MEL2320943	SA	MW218374	MW302286	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Aroramyces	sp.	MEL2320959	SA	MW218375	MW302287	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	rugisporum	OSC59662	NZ	DQ218784	DQ219164	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	rupticutis	OSC59667	NZ	DQ218838	n/a	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterogaster	sp.	H6973	SA	MW218372	MW302284	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterogaster	sp.	T16994	VIC	MW218373	MW302285	Hysterangiaceae	Hysterangineae (Hysterangiales)
Gen. prov. 15 Castellano	Hysterangium	sp.	AHF602	USA - AZ	DQ218854	DQ219185	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	T19263	MEX	DQ218849	DQ219180	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	calcareum	Gross97	EUR	DQ218776	DQ219149	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	pompholyx	Gross495	EUR	DQ218783	DQ219163	Hysterangiaceae	Hysterangineae (Hysterangiales)
Aroramyces	Aroramyces	gelatinosporus	H4010	AUS	DQ218809	DQ219118	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Aroramyces	radiatus	Verbeken99062	ZIMB	DQ218810	DQ219119	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Aroramyces	sp.	OSC122590	NEWCAL	DQ218814	DQ219123	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Aroramyces	sp.	OSC122858	ASIA	DQ218813	DQ219122	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Aroramyces	sp.	SM10030	NSA	DQ218815	DQ219124	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Aroramyces	sp.	T15013	SEASIA	DQ218811	DQ219120	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Aroramyces	sp.	T9930	IND	DQ218812	DQ219121	Hysterangiaceae	Hysterangineae (Hysterangiales)
Gen. prov. 16 Lebel & Castellano	Hysterangium	occidentale	OSC47048	WNA	AY574825	DQ219162	Hysterangiaceae	Hysterangineae (Hysterangiales)
Gen. prov. 17 Lebel & Castellano	Hysterangium	sp.	SEA29	QLD	MW438328	MW302300	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	SEA30	QLD	MW438323	MW302301	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	SM10007	GUYANA	DQ218869	DQ219200	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	SM10100	GUYANA	DQ218870	DQ219201	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	SM10166	GUYANA	DQ218871	DQ219202	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	T13345	THAI	DQ218872	DQ219203	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	T17501	SING	DQ218841	DQ219171	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	UFRN2112	BRZ	LT635647	LT635645	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	UFRN2115	BRZ	LT635648	LT635646	Hysterangiaceae	Hysterangineae (Hysterangiales)
Gen. prov. 18 Castellano & Lebel	Hysterangium	sp.	PDD82853	NZ	DQ218868	DQ219199	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	affine	T6884	AUS	DQ218831	n/a	Hysterangiaceae	Hysterangineae (Hysterangiales)
Gen. prov. 19 Castellano	Hysterangium	sp.	T3328	MEX	DQ218852	DQ219183	Hysterangiaceae	Hysterangineae (Hysterangiales)
Hysterangium	Hysterangium	sp.	Garcia3779	MEX	DQ218847	DQ219178	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	OSC122859	ASIA	DQ218859	DQ219190	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	T8997	WNA	DQ218876	DQ219207	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	album	T15139	ENA	DQ218774	DQ219147	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	cistophilum	T1088	EUR	DQ218777	DQ219150	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	clathroides	Zemere	EUR	DQ218832	DQ219151	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	crassum	OSC110447	—	AY574827	DQ219154	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	membranaceum	T12836	EUR	DQ218782	DQ219160	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	setchellii	OSC58071	WNA	DQ218839	DQ219167	Hysterangiaceae	Hysterangineae (Hysterangiales)
Gen. prov. 20 Castellano	Hysterangium	sp.	T22832	WNA	DQ218850	DQ219181	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	T27921	COSTA	DQ218875	DQ219206	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	aureum	OSC56988	WNA	DQ218775	DQ219148	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	coriaceum	Kers4984	EUR	DQ218833	n/a	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	coriaceum	OSC55265	ENA	DQ218834	n/a	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	coriaceum	OSC64939	WNA	AY574826	DQ219152	Hysterangiaceae	Hysterangineae (Hysterangiales)
	Hysterangium	crassirhachis	OSC58056	WNA	DQ218778	DQ219153	Hysterangiaceae	Hysterangineae (Hysterangiales)
Gen. prov. 2 Lebel	Aroramyces	sp.	H6547	VIC	MW417410	MW302213	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Aroramyces	sp.	MEL2364203	NSW	MW417417	MW302214	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	AWC42	VIC	MW417411	MW302212	Mesophelliaceae	Hysterangineae (Hysterangiales)
Chondrogaster	Chondrogaster	sp.	H170	WA	MW438325	MW302215	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Chondrogaster	sp.	H4362	QLD	MW449881	MW302217	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Chondrogaster	sp.	MEL2137016	VIC	MW417412	MW302218	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Chondrogaster	sp.	TL449	NSW	MW417415	MW302219	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Chondrogaster	sp.	TL1487	NSW	MW417414	MW302220	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Chondrogaster	sp.	TL1426	NSW	MW417413	MW302221	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Chondrogaster	sp.	T17536	CHN	MW449874	MW302224	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Chondrogaster	sp.	SEA10	QLD	MW449868	MW302225	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Chondrogaster	sp.	T11067	WNA	MW438324	MW302223	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Chondrogaster	sp.	MEL2238556	NSW	MW417405	MW302226	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Chondrogaster	angustisporus	MEL2105021	WA	MW417407	MW302216	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Chondrogaster	angustisporus	OSC62041	BRZ	DQ218822	DQ219135	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Chondrogaster	angustisporus	OSC62042	BRZ	MW449876	MW302222	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Chondrogaster	pachysporus	OSC49298	AUS	DQ218823	DQ219136	Mesophelliaceae	Hysterangineae (Hysterangiales)
Andebbia	Andebbia	pachythrix	MEL2124354	NSW	MW449879	MW302227	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Andebbia	pachythrix	MEL2238554	NSW	MW449880	MW302228	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Andebbia	pachythrix	OSC58809	NSW	DQ218808	DQ219117	Mesophelliaceae	Hysterangineae (Hysterangiales)
Gen. prov. 26 Castellano	Castoreum	sp.	MEL2238626	NSW	MW449869	MW302229	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Castoreum	sp.	T18910	NSW	MW417409	MW302230	Mesophelliaceae	Hysterangineae (Hysterangiales)
Gen. prov. 3 Castellano	Castoreum	sp.	MEL2389702	SA	MW417408	MW302241	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Castoreum	camphoratum	MEL2063469	NSW	MW417404	MW302231	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Castoreum	camphoratum	MEL2238635	NSW	MW417416	MW302232	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Castoreum	camphoratum	MEL2063470	NSW	MW449877	MW302233	Mesophelliaceae	Hysterangineae (Hysterangiales)
Gen. prov. 4 Castellano & Lebel	Malajczukia	amicorum	MEL2056858	TAS	MW449867	MW302235	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Malajczukia	amicorum	OSC59295	VIC	DQ218792	DQ219208	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Malajczukia	ingratissima	OSC59296	VIC	DQ218793	DQ219209	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Mesophellia	sp.	SEA37	QLD	MW449875	MW302237	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Mesophellia	sp.	MEL2389696	SA	MW449870	MW302238	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Mesophellia	sp.	SEA35B	QLD	MW438333	MW302239	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Mesophellia	brevispora	MEL2281255	WA	MW449872	MW302236	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Mesophellia	clelandii	MEL2042631	VIC	MW449878	MW302234	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Mesophellia	clelandii	OSC59292	VIC	DQ218795	DQ219211	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Mesophellia	glauca	OSC56986	TAS	DQ218878	DQ219212	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Mesophellia	sabulosa	OSC55918	VIC	DQ218879	DQ219213	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Mesophelllia	trabalis	OSC59282	VIC	DQ218880	DQ219214	Mesophelliaceae	Hysterangineae (Hysterangiales)
Mesophellia	Mesophellia	arenaria	OSC59306	TAS	DQ218877	DQ219210	Mesophelliaceae	Hysterangineae (Hysterangiales)
Nothocastoreum	Nothocastoreum	cretaceum	MEL2356006	WA	MW246680	MW302240	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Nothocastoreum	cretaceum	OSC79832	AUS	DQ218881	DQ219215	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Nothocastoreum	cretaceum	OSC79925	AUS	n/a	DQ219216	Mesophelliaceae	Hysterangineae (Hysterangiales)
Gen. prov. 5 Lebel	Chondrogaster	sp.	SEA6B	QLD	MW246665	MW302273	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Chondrogaster	sp.	TL1294	NSW	MW246677	MW302274	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Chondrogaster	sp.	T19877	VIC	MW246684	MW302275	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Chondrogaster	sp.	TL1097	NSW	MW246685	MW302276	Mesophelliaceae	Hysterangineae (Hysterangiales)
Gen. prov. 6 Lebel & Davoodian	Gummiglobus	sp.	H7679	WA	MW449873	MW302242	Mesophelliaceae	Hysterangineae (Hysterangiales)
Castoreum	Castoreum	sp.	SEA2	QLD	MW246674	MW302246	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Castoreum	sp.	SEA3	QLD	MW246668	MW302247	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Castoreum	sp.	OSC122814	AUS	DQ218821	DQ219134	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Castoreum	radicatum	MEL2354501	QLD	MW246672	MW302244	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Castoreum	radicatum	MEL2364205	NSW	MW246690	MW302250	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Castoreum	tasmanicum	MEL2041148	VIC	MW246695	MW302243	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Castoreum	tasmanicum	MEL2056682	VIC	MW246683	MW302248	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Fusicastoreum	sp.	MEL2354440	QLD	MW246667	MW302245	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Mesophellia	arenaria	MEL2356530	TAS	MW246688	MW302249	Mesophelliaceae	Hysterangineae (Hysterangiales)
Gummiglobus	Gummiglobus	sp.	SEA22	QLD	MW246691	MW302252	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Gummiglobus	agglutinosporus	OSC58784	AUS	DQ218830	n/a	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Gummiglobus	agglutinosporus	MEL2042096	VIC	MW246693	MW302251	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Gummiglobus	agglutinosporus	MEL2105039	VIC	MW246670	MW302254	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Gummiglobus	joyceae	MEL2314623	QLD	MW438332	MW302253	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Gummiglobus	joyceae	OSC59485	AUS	DQ218772	n/a	Mesophelliaceae	Hysterangineae (Hysterangiales)
Gummivena	Gummivena	potorooi	MEL2104390	WA	MW246678	MW302255	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Gummivena	potorooi	MEL2314967	WA	MW246696	MW302256	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Gummivena	potorooi	MEL2105001	WA	MW246673	MW302257	Mesophelliaceae	Hysterangineae (Hysterangiales)
Gen. prov. 7 Davoodian, Lebel & Castellano	Aroramyces	sp.	TL1701	NSW	MT947437	MT947438	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Chondrogaster	sp.	SEA9	QLD	MT947436	MW264847	Mesophelliaceae	Hysterangineae (Hysterangiales)
Gen. prov. 8 Hosaka	Chondrogaster	sp.	H6586	VIC	MW246682	MW302260	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Chondrogaster	sp.	TL2871	SA	MW246692	MW302262	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Chondrogaster	sp.	MEL2364057	NSW	MW246671	MW302267	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Chondrogaster	sp.	MEL2364304	NSW	MW246697	MW302268	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Chondrogaster	sp.	TL2888	SA	MW246689	MW302269	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Chondrogaster	sp.	TL2889	SA	MW246687	MW302270	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	T16823	ACT	MW246686	MW302258	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	T36459	USA - CA	MW246694	MW302259	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	PSC4372	SA	MW246679	MW302261	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	H6761	VIC	MW246666	MW302263	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	SEA27	QLD	MW246681	MW302265	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	H5573	PNG	MW246669	MW302264	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	T14749	WA	MW246698	MW302266	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	T6923	AUS	DQ218855	DQ219186	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	T15362	NT	MW246675	MW302271	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	T15375	NT	MW246676	MW302272	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	MEL2057692	NSW	DQ218848	DQ219179	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Hysterangium	gardnerii	T6950	AUS	DQ218835	DQ219157	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Hysterangium	inflatum	H4035	AUS	DQ218836	DQ219159	Mesophelliaceae	Hysterangineae (Hysterangiales)
Gen. prov. 9 Davoodian	Hysterangium	sp.	H381	TAS	MW449871	MW302281	Mesophelliaceae	Hysterangineae (Hysterangiales)
Gen. prov. 10 Hosaka	Chondrogaster	sp.	MEL2305115	QLD	MW449861	MW302277	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Chondrogaster	sp.	SEA7B	QLD	MW449864	MW302280	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	H2022	AUS	DQ218856	DQ219187	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	H4262	AUS	DQ218773	DQ219146	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	T22535	QLD	MW449862	MW302278	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Hysterangium	sp.	SEA270	QLD	MW449863	MW302279	Mesophelliaceae	Hysterangineae (Hysterangiales)
	Hysterangium	aggregatum	MEL2049882	VIC	DQ218844	DQ219175	Mesophelliaceae	Hysterangineae (Hysterangiales)

Each gene was aligned using MAFFT online (Katoh ), visually inspected, and manually adjusted as required. Phylogenetic analyses of each individual gene were conducted using the methods outlined in the next paragraph. Dendrograms from these analyses were then compared using PHYLO.IO (Robinson ) to assess concordance. The topologies between each gene were found to be almost completely concordant at the generic level and below, corroborating all genera and species (with the exception of specimen H381 which appeared in different positions). Also, many relationships between genera were corroborated between atp6 and tef1. In the individual gene analyses, higher taxonomic levels (e.g. family, suborder) were either not recovered or recovered with low support.

After the assessment of the individual gene phylogenies, atp6 and tef1 were concatenated, resulting in an alignment of 1 464 sites long with 223 terminals. MrBayesS v. 3.2.7a (Ronquist ) was used via the CIPRES REST API (Miller ) for Bayesian inference (BI) analysis. An analysis using default priors and the following parameters was run for 20 000 000 generations; nstopts: 6, nucmodelopts: 4by4, rateopts: gamma, nrunsval: 2, nchainsval: 4, tempval: 0.200, swapfreqval: 1, nswapsval: 1, samplefreqval: 1 000, burninfracval: 0.5, vparam.stopval: 0.003, sump_burninfrac: 0.5, sumpnruns: 2, sumt_burninfrac: 0.5, sumtnruns: 2, sumtntrees: 1. The average potential scale reduction factor reported for all parameters was 1.038. The alignment and resultant consensus phylogram is deposited in TreeBASE under study number 27527. To corroborate our topology and support values, we conducted additional separate analyses using different outgroup taxa (Geastrales), extended generations (ranging from 22 000 000 to 59 000 000), different models of rate variation among sites, and different partitions i.e. one partition, two partition (each gene), or multi-partition (codon positions for each gene, as well as introns for tef1) analyses. We also conducted maximum likelihood (ML) analysis using RAxML software (Stamatakis ) via the CIPRES REST API with the following options; dna_gtrcat: GTRGAMMA, select_analysis: fa, choose_bootstrap: x, bootstrap_value: 1 000. Taxon names at individual terminals in the phylogram are field-based, verbatim identifications, from various mycologists.

RESULTS

The BI analysis recovered Hysterangiales (Bayesian posterior probability, bpp = 1) with the four constituent families Gallaceaceae, Hysterangiaceae, Mesophelliaceae, and Phallogastraceae fam. nov. (all bpp = 1), containing numerous described and undescribed genera (Supplementary Fig. S1, Fig. 3 - Parts 1,2,3). In total, 26 provisional undescribed genera were inferred (25 Hysterangiales and 1 Phallales). The results of the additional BI analyses and ML analysis were not substantively different from our primary BI analysis, corroborating all taxa indicated in Fig. 3 and Table 1. Phallogastraceae is accommodated by a newly established suborder, Phallogastrineae (described below, Fig. 3 - Part 1), and the families Mesophelliaceae (Fig. 3 - Part 1), Hysterangiaceae (Fig. 3 - Part 2) and Gallaceae (Fig. 3 - Part 3) are accommodated in the new suborder Hysterangineae. Trappeaceae is not in Hysterangiales, since the type species of Trappea, T. darkeri, is inferred to be in Phallales based on this and previous analyses (Hosaka , Sulzbacher ; Fig. 3 - Part 3, Table 1). Neither Trappea pinyonensis nor T. phillipsii belong in Trappea given their position within Phallogastraceae (Xu & Luo 2003, Hosaka ; Fig. 3 - Part 1); the combination to Phallogaster is made here. It should be noted that true Protubera lies outside of Hysterangiales, since the type (P. maracuja) and related species belong in Protophallaceae, Phallales (Trierveiler-Pereira ). Thus, Protubera hautuensis, P. nothofagi, and all other taxa appearing in Fig. 3 - Part 3) labelled as Protubera are not true members of the genus (this includes P. canescens, which is a synonym of Ileodictyon gracile in Phallaceae, Phallales).

Fig. 3.

Part 1. Phylogram from Bayesian analysis showing families and genera within Hysterangiales. Node A indicates Phallogastrineae subord. nov.; node B indicates Hysterangineae subord. nov. Maximum likelihood (ML) bootstrap values / Bayesian posterior probabilities (bpp) are shown at the nodes. The scale bar shows substitutions per site. Where bpp ≥ 0.95 and ML bootstrap ≥ 70%, branches are thickened. Type species indicated by a blue asterisk *. The asterisk in parentheses (*) denotes Ileodictyon, the currently accepted genus for Protubera canescens. Australian (AU) States and Territories indicated by: WA (Western Australia), NT (Northern Territory), QLD (Queensland), NSW (New South Wales), VIC (Victoria), TAS (Tasmania), SA (South Australia). United States (USA) states indicated by: ARIZ (Arizona), CAL (California), COL (Colorado), ID (Idaho), OR (Oregon). Other geographic areas indicated as follows: NZ (New Zealand), NewCal (New Caledonia), PNG (Papua New Guinea), BRZ (Brazil), MEX (Mexico), WNA (western North America), ENA (eastern North America), CHN (China), Guyana (Guyana), SSA (southern South America), NSA (northern South America), ASIA (Asia), SEASIA (southeast Asia), SING (Singapore), THAI (Thailand), IND (India), EUR (Europe), COSTA (Costa Rica), ZIMB (Zimbabwe).

Taxonomy

Order K. Hosaka & Castellano

Castellano, T. Lebel, Davoodian & K. Hosaka, MycoBank MB 838485.

Basidiomes sequestrate, small (0.2 cm wide) to larger (up to 5 cm long and 3 cm wide), subglobose to irregularly subovoid, with a tapered to irregularly shaped base, single or caespitose, with white rhizomorphs (rhizomorphs sometimes discolouring pinkish). Basidiome surface smooth to velvety to finely tomentose, white to clay white (discolouring pinkish to salmon buff to reddish or faint lilac). Peridium 160–2 000 μm thick. Columella branched, whitish to semi-translucent, gelatinized. Gleba varies from green, olivaceous green, greyish olive to pale olive; gelatinized, loculate, locules small. Basidia clavate to narrowly clavate to irregularly cylindrical, thin-walled, hyaline, 6–8-spored. Sterigmata small to indistinct. Spores smooth, elongate-ellipsoid to oblong, thin-walled, utricle absent, hyaline singly, olive buff to honey yellow or pale green in mass. Clamp connections present.

Phylogenetic taxon definition of the suborder: The largest crown clade containing Phallogaster saccatus Morgan 1893, but not Hysterangium clathroides Vittad. 1831, Mesophellia arenaria Berk. 1857, and Gallacea scleroderma (Cooke) Lloyd 1905. This is a maximum crown-clade definition (Hibbett ).

Type family: Phallogastraceae Castellano, T. Lebel, Davoodian & K. Hosaka non Phallogastraceae Locq., De Taxia Fungorum: I. Syllabus 1A: 56. 1974.

Castellano, T. Lebel, Davoodian & K. Hosaka, MycoBank MB 838484.

Basidiomes sequestrate, small (0.2 cm wide) to larger (up to 5 cm long and 3 cm wide), subglobose to irregularly subovoid, with a tapered to irregularly shaped base, single or caespitose, with white rhizomorphs (rhizomorphs sometimes discolouring pinkish). Basidiome surface smooth to velvety to finely tomentose, white to clay white (discolouring pinkish to salmon buff to reddish or faint lilac). Peridium 160–2 000 μm thick. Columella branched, whitish to semi-translucent, gelatinized. Gleba varies from green, olivaceous green, greyish olive to pale olive; gelatinized, loculate, locules small. Basidia clavate to narrowly clavate to irregularly cylindrical, thin-walled, hyaline, 6–8-spored. Sterigmata small to indistinct. Spores smooth, elongate-ellipsoid to oblong, thin-walled, utricle absent, hyaline singly, olive buff to honey yellow or pale green in mass. Clamp connections present. Odour sometimes fetid. Species apparently saprotrophic, occurring on decaying wood or leaves, or partially buried in litter.

Type genus: Phallogaster Morgan, J. Cincinnati Soc. Nat. Hist. 15: 171. 1893.

Notes: Phallogastraceae Locq. (1974) is invalid in accordance with Art. 39:1 of the Shenzen code. This is the only clade in Hysterangiales with an apparently non-mycorrhizal habit. Although the number of taxa is thus far very limited, the phylogenetic relationships within the family/suborder strongly indicate reciprocal monophyly of the Northern Hemisphere (“Phallogaster clade”) and Southern Hemisphere clades (“Gen. prov. 1”) (Fig. 3 - Part 1).

In addition to a traditional morphology-based description for the corresponding suborder (Phallogastrineae subord. nov.), we have also applied a phylogenetic taxon definition for the suborder (see Hibbett ). More taxon sampling in the future may require further amendment of the morphological definition of the suborder, whereas our phylogenetic taxon definition of Phallogastrinae will remain stable.

(States) K. Hosaka, Castellano, Davoodian & T. Lebel, MycoBank MB 838487.

Basionym: Trappea pinyonensis States, Mycotaxon 41: 128. 1991. MycoBank MB 129849.

Typus: USA, Arizona, Walnut Canyon National Monument, Coconino County, on sandy soil under Pinus edulis, 10 Oct. 1986, J. States AHF-530 (holotype ASC).

(Harkn.) K. Hosaka, Castellano, Davoodian & T. Lebel, MycoBank MB 840085.

Basionym: Hysterangium phillipsii Harkn., Proceedings of the California Academy of Sciences 1(8): 255. 1899. MycoBank MB 187085.

Synonym: Trappea phillipsii (Harkn.) Castellano, Mycotaxon 38: 7. 1990. MycoBank MB 127551.

Typus: USA, California, Wire Bridge, Placer County, in soil, associated with Quercus, Jan. 1899, C.L. Phillips (Harkness 234, holotype BPI)

Notes: Although the species was not included in the phylogenetic analysis in this study, it has clearly been demonstrated to be the sister taxon to Phallogaster (Trappea) pinyonensis by Hosaka . Its basidiome surfaces stain pinkish when bruised, which is also a common characteristic with other species in the genus Phallogaster.

Excluded taxa

A-S. Xu & D.Q. Luo, Mycosystema 22: 192. 2003. MycoBank MB 489004.

Notes: Based on the original description of T. cinnamomea (Xu & Luo 2003), its basidiome surfaces have the staining reaction to pink, which is similar to Trappea phillipsii and T. pinyonensis. However, we so far have no access to the specimens and no DNA data from the species are currently available. Until more definitive evidence becomes available, we keep this taxon in the genus Trappea.

Castellano, T. Lebel, Davoodian & K. Hosaka, MycoBank MB 838486.

Basidiomes sequestrate, hypogeous or epigeous, and can be small (0.1 cm wide) to larger (up to 10 cm wide), subglobose to irregularly subovoid without tapered base, single or gregarious, often covered with adhering sand and soil or encased in debris and rootlets, usually with conspicuous white to off-white rhizomorphs at base or along sides of basidiomata. Basidiome surface smooth to velvety to finely tomentose, often white to off-white in colour and often discolouring pinkish, reddish, yellowish or brownish, but purple to violet in some species. Peridium adherent to often readily separable from gleba, elastic, glutinous or hard and brittle, 1–4-layered, sometimes incorporating mycorrhizae. Columella branched, whitish to semi-translucent and gelatinized or a soft to corky or rubbery central core or lacking such structures. Gleba varies from green, olivaceous green, greyish olive, brown to ochraceous or pinkish; gelatinous to cartilaginous or with a powdery spore mass at maturity, often with labyrinthine to elongated to circular locules. Basidia clavate to narrowly clavate to irregularly cylindrical, thin-walled, hyaline, mostly 4-spored. Spores ellipsoid to oblong to fusoid, smooth to minutely verrucose or with long spines beneath a utricle, or sometimes with longitudinal ridges, thin- to thick-walled, often covered with a wrinkled to inflated or ephemeral utricle, hyaline, pale green, or brown in KOH, inamyloid, sometimes weakly dextrinoid. Odour faint, fetid, or sometimes sweet. Clamp connections present or absent. All species are presumably ectomycorrhizal with various vascular plants including Dipterocarpaceae, Fagaceae, Myrtaceae, Nothofagaceae, and Pinaceae.

Phylogenetic taxon definition of the suborder: The largest crown clade containing Hysterangium clathroides Vittad. 1831, but not Phallogaster saccatus Morgan 1893. This is a maximum crown-clade definition (Hibbett ).

Type family: Hysterangiaceae E. Fisch., in Engler & Prantl, Nat. Pflanzenfam., Teil. I (Leipzig): 304. 1899. [1900]

Notes: The Hysterangineae is exclusively composed of sequestrate taxa which are ectomycorrhizal with various vascular plants insofar as inferred from available studies. Most species in Hysterangineae have rather specific ectomycorrhizal hosts, usually restricted to a single plant family. For example, species distributed in the Southern Hemisphere are associated with Myrtaceae (mostly with Eucalyptus spp. and/or Kunzea/Leptospermum spp.) or Nothofagaceae (Castellano & Beever 1994, Hosaka ).

This suborder is much more speciose than Phallogastrineae and many more new species, especially from Australia, remain to be described for all three families, i.e., Hysterangiaceae, Mesophelliaceae and Gallaceaceae. We believe that the family-level phylogeny is robust (Fig. 3, Supplementary Fig. S1), but more taxon sampling in the future may require further amendment of the morphological definition of the suborder. Therefore, as is the case for Phallogastrineae, we have also applied a phylogenetic taxon definition approach as summarized by Hibbett .

DISCUSSION

In addition to revealing new taxa, our analysis highlights prominent biogeographic patterns in Hysterangiales. Trans-Tasman distributions are numerous throughout Hysterangiales; almost every New Zealand lineage inferred in our phylogram is sister to an Australian lineage, at various taxonomic scales. Gondwanan disjunctions are also represented, for example "Gen. prov. 17" (Fig. 3 - Part 2) contains an Australian and paleotropical clade sister to a northeastern South American clade. Some human-mediated introduction events are apparent as well e.g. Chondrogaster angustisporus (OSC62041 - holotype) is from planted Eucalyptus in Brazil (Giachini ). Hosaka postulated that the Hysterangiales originated in Australia or Eastern Gondwana and expanded in range over time, possibly through long-distance dispersal. Sheedy inferred that Hysterangiales was the first group of Agaricomycetes to become sequestrate in Australia (ca. 83 million years ago). The rate of sequestration of Agaricomycetes was inferred to have increased in Australia after separation from Antarctica, the timing of which overlaps with the radiation of potential mycorrhizal plant associates as well as the emergence of specialized mycophagous marsupials. Although periods of aridification were evidently not the sole driver of sequestration, they likely had a major influence on the diversity of sequestrate fungi in Australia, including Hysterangiales (Sheedy ).

Our analysis indicates phylogenetic signals for some prominent macroscopic features. In the Mesophelliaceae, the clade unifying Gummivena, Gummiglobus, and Castoreum is comprised of species that have gummy-like mycelium and/or outer glebal tissue (Fig. 1N, O). Species in the clade containing Chondrogaster, Andebbia, Mesophellia, Nothocastoreum, and related provisional genera have a powdery spore mass at maturity and also incorporate roots and soil in a multi-layered mycelial crust surrounding the basidiome (in Nothocastoreum this falls off easily and remains in the soil) (Fig. 1J–M). In provisional genera 8 through 10, the basidiomes are typically encased in a mycelial soil crust, and the glebal tissue is gelatinized. Macroscopic characters of Hysterangiaceae overlap somewhat with various clades in the Mesophelliaceae and Gallaceaceae, including having a gelatinized gleba and varying degrees of rhizomorph development across the surface of basidiomes (Fig. 1G–I). In Gallaceaceae, most lineages have a firm, cartilaginous peridium surrounding a gelatinized gleba (Fig. 1D–F), and spores lacking an utricle (Fig. 2A). The condition of having ridged spores (Fig. 2C) is not monophyletic in Hysterangiales; this character was previously thought to be diagnostic for the genus Austrogautieria (Stewart & Trappe 1985) but now appears in two well-supported, distinct clades in Gallaceaceae (Austrogautieria and "Gen. prov. 24"; Fig. 3 - Part 3).

Numerous provisional genera and species have been revealed in this study, which will be described by the respective authors of this paper and other collaborators in upcoming publications. We believe our current approach of recognising numerous provisional genera is a more accurate and conservative estimate of diversity than to lump them into fewer, larger genera. In addition to strong phylogenetic signals, each provisional genus is readily distinguishable by macroscopic and microscopic characters, but species level differentiation within genera requires more sampling in many of these taxa. Moreover, our phylogenetic analyses show that some existing genera, such as Castoreum and Gummiglobus in Mesophelliaceae, are closely related to each other within their respective families, but our provisional genera are more distantly related to these existing genera (Fig. 3, Supplementary Fig. S1). More sampling throughout Australasia and South America will likely uncover additional clades and aid in further refining generic and specific boundaries.