Holotype (PDD 27100); Isotype (Herb. HK. ZT 68/246): 'Waiuta, E of Totara Flat, Prov. Westcoast, N.Z.; leg. Horak, 2.IV.1968'.

Pileus 25-50 mm diam., conic becoming broadly conico-umbonate, plane with conspicuous small umbo in age, olive turning olive-brown at the centre, dark brown towards the striated margin, viscid when moist, hygrophanous, glabrous. Lamellae adnexed to subfree, ventricose, pink to reddish-brown turning pallid ferruginous in age, crowded, gill edge whitish, crenulate. Stipe 100-150 x 4-6 mm, gradually attenuated towards the base, rooting, brownish, reddish-brown towards the base, lilac or violaceous colours lacking, dry, glabrous, tough, hollow, rhizoids absent, single. Context olive in pileus and upper portions of the stipe, fibrillose-stuffed. Taste and odor fragrant, like burnt hair. Chemical reactions on pileus: KOH - yellow-brown; HCI and NH₃ - negative.
Spores 8-9 x 5-5.5 µm, amygdaliform with a short and blunt beak, distinctly verrucose, ferruginous. Basidia 26-30 x7-8 µm, 4-spored. Cheilocystidia 22-30 x 2-6 µm, narrowly clavate, occasionally subcapitate, hyaline, membrane thin-walled abundant on gill edge. Pleurocystidia absent. Cuticle a cutis consisting of repent, cylindric, slightly gelatinized hyphae (2-6 µm diam.), encrusted with brownish pigment. Clamp connections absent.

Amongst Sphagnum in swamp-forest under Nothofagus cliffortioides, Phyllocladus alpinus, Libocedrus bidwillii etc. New Zealand.

Pileo 25-50 mm lato, conico dein conico-umbonato, e olivaceo brunneo-olivascente, viscido, glabro. Lamellis adnatis vel subliberis, ex carneo-brunneo ferrugineis. Stipite 100-150 x 4-6 mm, radicato, pallide brunneo. Odore ingrato. Sporis 8-9 x 5-5.5 µm, amygdaliformibus, verrucosis, ferrugineis. Cystidiis cylindrico-subcapitatis, 22-30 x 2-6 µm. Epicute ex hyphis cylindricis cutem formantibus, pigmento brunneo incrustatis, septis defibulatis. Inter Sphagnum in silvis nothofagineis. Novazelandia.

The habit and colours of Phaeocollybia longipes remind one of Ph. festiva (Fr.), Ph. pseudofestiva Smith or Ph. olivacea Smith. However, the spores of Ph. festiva (Fr.) (within the European-Japanese area of distribution) are ovoid and not beaked at the ape. Furthermore the spores and cheilocystidia of Ph. pseudofestiva Smith are distinctly different concerning size and shape. Finally Ph. olivacea Smith is distinguished by its robust habit, its glutinous cuticle, the larger strongly beaked spores and the capitate cheilocystidia

Holotypus (PDD 27100): 'Waiuta, N.Z.; leg. Horak, 2.IV.1968'.