OTHER COLLECTIONS EXAMINED: NEW ZEALAND: AUCKLAND: Waitakere Ranges, Glen Esk Valley, B.E.G. Molesworth, 19 Aug 1947 (PDD 5581, OSC); Waitakere Ranges, Kauri Grove Track, R.P. Korf & R.E. Beever 83, 13 Aug 1981 (PDD 52007); same locality, R. E. Beever85, 12 Sep 1981 (PDD 52009); same locality, R.E. Beever 598, 27 May 1986 (PDD 52010, OSC). COROMANDEL: Thames, Kauaeranga Valley, S.D. Baker, 26 Aug 1954 (PDD 13629, OSC); Coromandel Forest Park, track to Tarawaere Dam, L.E. Hooper, 1 Sep 1986 (PDD 51929). TAUPO: Urewera, Te Awhiti, ?collector, Jul 1948 (PDD 6229, OSC); Turangi, Pihanga, J.M. Dingley, 10 Oct 1968 (PDD 45877, OSC); Karioi, Rotokuru Ecological Reserve, D.C. Hogan, 7 Sep 1987 (PDD 55124).

Basidiomata up to 4 cm diam., globose to depressed, slightly ridged, white to bluish white when fresh, bruising pale pink to pale grey red, especially on ridges, surface finely tomentose, tomentum easily rubbing off upon handling; EtOH red to reddish brown. Gleba gelatinous, pale olive grey to greyish olive; locules elongate, empty. Rhizomorph stout, single, soon branching, up to 2 mm diam., concolorous with peridium, attached at base. Columella distinct, dendroid, gelatinous, translucent. Taste not noted. Odour not noted. Peridium fragile when dried, not easily separable from gleba, 450-750 dim thick, 2-layered; epicutis 200-400 µm thick, of hyaline, thin-walled, interwoven, inflated hyphae, 5-60 µm diam., clamp connections absent; subcutis 250-350 µm thick, of hyaline, interwoven hyphae, 2-4 µm diam., in a gelatinised matrix, clamp connections absent. Sutures infrequent, of hyaline, interwoven hyphae, 2-5 µm diam., without clamp connections, connecting some locules to epicutis. Trama up to 80 µm thick, of hyaline, thin-walled, interwoven hyphae, 2-3 µm diam., in a gelatinised matrix, clamp connections absent. Basidia not observed, "8 spored" (Cunningham). Spores smooth, 4-5.5 x 1.5-2 gin, ellipsoid; apex obtuse, base obtuse; wall <0.5 µm thick. Utricle absent. Spore colour in KOH hyaline to pale green singly, pale green in mass.

New Zealand.

Habitat: epigeous and buried amongst decaying leaves and white-rotted branches in podocarp-broadleaf and Nothofagus forests. Season: February through October.

Basidiomata usque ad 4 cm diam., globosa vel depressa, alba vel lactea, contundentibus pallide rosea vel pallide lateritia, minute tomentosa. Gleba gelatinosa, pallide olivaceo-cinerea vel cinereo-olivacea, loculis elongatis, vacuis. Rhizomorpha singularis, usque ad 2 mm diam., peridio concolor. Columella dendroidea, gelatinosa, translucens, truncata. Peridium fragile, non facile separabile, 450-750 µm crassum; epicute 200-400 µm crassa, hyphis hyalinis, intertextis, inflatis, 5-60 µm diam.; subcute 250-350 µm crassa, hyphis hyalinis intertextis, 2-4 µm diam., in matrice gelatinosa. Cutis suturis infrequentibus, hyphis hyalinis, intertextis, 2-5 µm diam. Trama usque ad 80 µm crassa, hyphis hyalinis, intertextis, 2-3 µm, in matrice gelatinosa. Sporae laeves, 4-5.5 x 1.5-2 µm, ellipsoideae, apice obtuso; paries minus quam 0.5 µm crassus; sin gulariter hyalinae vel pallide virides, aggregate pallide virides. Holotypus PDD 8311.

ETYMOLOGY: From Maori Hautu, the district where the type was collected.
REMARKS: Cunningham proposed the name Hysterangium hautu without a Latin description after 1935, so it is a nomen nudum in accordance with Article 36.1 of the Botanical Code. We validate the specific epithet, as hautuensis, in accordance with the code recommendations on forming epithets from place names.
The occurrence of sutures through the gelatinised subcutis places this species in genus Protubera. The combination of thin peridial layers, infrequent sutures, and peridium colouring, especially upon handling, separates P. hautuensis from all other Protubera species.
The record of H. hautu from Queensland by Cribb (1958) is erroneous and based on a distinct, as yet unnamed, taxon.

TYPE: NEW ZEALAND, TAUPO, Waimarino, J.C. Neill, Feb 1930 (holotype PDD 8311; isotypes DAOM 116161, K, OSC) (type of Hysterangium hautu).

Plants irregularly tuberiform, much shrunken and wrinkled when dry, fresh plants to 4 cm. diameter, drying to 2.5 cm., exterior clingy sage-green, brown where exposed, pallid dingy create and dull below, attached by a prominent rooting strand. Peridium 300-400 microns thick, of an outer layer of pseudoparenchyma exteriorly coated with a delicate fibrillose lacer of hyphae coated with crystals, and a thick inner layer of gelatinized hyphae. Gleba olivaceous. cells irregular, 3-4 to mm, subglobose in fresh plants, traversed by a branched columella; at maturity sometimes becoming gelatinized and collapsing to a thin compressed layer tramal plates 50-75 microns thick, of gelatinized hyphae; basidia 8-spored.. Spores elongate-elliptical, 4.5-5 x 1.5-2 microns, hyaline or tinted, smooth.

Distribution: Auckland, Waimarino,.1. C. Neill, Type Collection.