SPECIMENS EXAMINED: NEW ZEALAND: AUCKLAND: Waitakere Ranges, Cascades Loop Tr., on dead frond Cyathea dealbata, P. R. Johnston D1 &G. J. Samuels, 9 Sep 1981, PDD 41794. GISBORNE: Urewera National Park, Lake Waikaremoana, Lake Ruapani Tr., on dead frond Dicksonia lanata, P. R. Johnston D454, 24 Nov 1988, PDD 56634. NORTHLAND: Russell Forest,Punaruku Rd, Hori Wehi Wehi Tr., on dead fronds Dicksonia sp., P. R. Johnston D1107 & L. Morin, 8 Aug 1994, PDD 63497. TAUPO: Pureora Forest, Mt Pureora, Link Tr., on dead frond Dicksonia squarrosa, P. R. Johnston D1423 & B. M. Spooner, 24 Aug 1999, PDD 70965. AUSTRALIA: VICTORIA: Wait-a-While Rd, near Beech Forest, on Dicksonia antarctica, K. & G.Beaton 260, 20 Sep 1964, MELU, holotype; Mt Torbrek, near Eildon, on Dicksonia antarctica, G. Weste & G. Beaton 260a, 3 May 1975, MELU. TASMANIA: south-west, Rutherfords Rd, SE side,N of St Johns Ck crossing, on Dicksonia sp., T. W. May & B. A. Fuhrer, 8 May 1996, MEL 2066941, PDD 71686.

DESCRIPTION: Apothecia developing on dead fronds, erumpent from beneath epidermis, with flap of host tissue pushed to one side at base of apothecium, arising from small patch of compact, hyaline tissue confined to upper few layers of host cells across base of apothecium. Apothecia 0.5-1 mm diam., sessile, disc pale yellowish, receptacle pale to dark brown, with a row of massive, tapering, pale, whitish appendages up to 0.8 mm long. Ectal excipulum twol ayered; outer layer up to 50 µm thick, of textura angularis to textura prismatica with elements oriented at high angle to receptacle surface, comprising brick-shaped to angular, 6-10-µm-diam. cells with walls thick, hyaline, encrusted with yellowbrown material on outermost cells, gelatinous; inner layer up to 50 µm thick near edge of disc, 10-15 µm at sides of receptacle, comprising long cylindric, 2.5-3-µm-diam. cells with walls thick, hyaline (outermost cells encrusted with yellow-brown material), gelatinous. Medullary excipulum comprising 65-µm-deep layer of cylindric, partly tangled cells oriented more or less perpendicular to host surface,4-6 µm diam., with walls slightly thickened, hyaline, slightly gelatinous. Excipular hairs arising from outer layer of ectal excipulum, up to 800 x 3 µm, cylindric with rounded apex, walls thick, smooth, hyaline, dextrinoid in Melzer's reagent (under interference contrast microscopy with amyloid appearance at some angles), numerous hairs aggregated into tight groups forming triangular, tapering appendages, 60-80 µm wide at base. Subhymenium comprising 2-4-µm-diam. hyphae with walls hyaline, thin, nongelatinous. Paraphyses 1.5 µm diam., apex slightly swollen to 2.5-3 µm diam., unbranched, extending 15-30 µm beyond asci, embedded in common hyaline gelatinous matrix. Asci 90-115(-130) x 5.5-7 µm, cylindric, tapering slightly to subtruncate apex, wall thickened at apex, apical pore sometimes amyloid, 8-spored, spores overlapping uniseriate or biseriate, spores extending 65-80 µm from ascus apex. Ascospores 10-14.5 x 3-3.5 µm, elliptic to fusoid, ends more or less acute, flattened one side, often slightly curved in side view, 0-1-septate, wall hyaline.

NOTES: H. dicksoniae is macroscopically similar to the other pale-coloured Hispidula spp., but can be distinguished by its narrower ascospores, and its substrate. Beaton & Weste (1977) placed this fungus in Cyathicula. They noted that they did so with "some hesitation", but that there was no other satisfactory genus for their fungus. Although some Cyathicula species have large, tooth-like appendages around the margin of the disc, these are simply extensions of the excipular tissue, and have the same anatomical structureas the highly gelatinised excipulum of this genus. The apothecial appendages of H. dicksoniae and the other Hispidula species comprise anatomically distinct hairs. Carpenter (1981) excluded H.dicksoniae from Cyathicula, compared its excipular structure with Hymenoscyphus, but otherwise made no attempt to recombine this species. An additional Tasmanian collection (Mt Field National Park, Lyrebird Nature Walk, on Dicksonia antarctica dead fronds, P. R. Johnston Tas 129 & A. K. Mills, 26 May 1988, HO, PDD 54963) from Dicksonia matches H. dicksoniae macroscopically, but has slightly wider asci (7-8.5 µm) and ascospores (4-4.5 µm). It could represent a distinct species, but until more material is available from Australia to enable assessment of variation between populations of these fungi, its identity remains doubtful