Additional Specimens Examined. NEW ZEALAND (all on Rhopalostylis sapida). NORTH ISLAND. Auckland: Waitemata City, Waitakere Ranges, Cascades, 14 Mar 1980, Samuels (80-48) & Kendrick (PDD 49648), 7 May 1981, Samuels (81-76), Johnston & Horak (NY, PDD 45720); Cowan Track, 27 Apr 1983, Samuels (83-30), Johnston & Petersen (NY, PDD 46841); Fairy Falls Track, 26 Jan 1980, Samuels (80-11) & Kendrick (NY, PDD 49626). Coromandel: Little Barrier Island, Haowhenua Stream, 21 Feb 1976, Samuels 76-20 (NY, PDD 47021), 76-47 (NY, PDD 47032). SOUTH ISLAND. Westland: Vic. Greymouth, Rapahoe Scenic Reserve, Pt. Elisabeth Walkway, 1 May 1985, Samuels (85-48), Johnston, Kohn & Stengs (NY, PDD 50058). INDONESIA. NORTH SULAWESI: Eastern Dumoga-Bone National Park, Camp Edwards, 00°35'N, 121°51'E, 664 m, on palm sheathing base, 6-9 Oct 1985, Samuels 2062, 2066, 3065 (all BO, NY).

Anamorph: Acremonium sp.
Mycelium not visible. Perithecia 230-350 µm. diam., solitary to gregarious, superficial on a minute basal stroma and difficult to remove from the substrate, globose to tympaniform, nonpapillate or with a minute papilla in the middle of the flat to broadly rounded apex; cupulate or not collapsing when dry; orange, not changing color in 3% KOH; scaly to waned, rarely smooth. Cells at surface of perithecial wall nearly circular in outline, (15)20-30(-40) µm in greatest dimension, walls :51 µm thick. Perithecial wall 40-80 µm wide at the perithecial apex, of two ± distinct regions: outer region 30-70 µm wide, cells circular to elliptic in outline, 18-30(-40) µm diam., walls less than or equal to 1.5 µm thick; inner region ca. 10 µm wide, cells flattened; perithecial opening of small cells continuous with the inner region of the perithecial wall and merging with the periphyses within; perithecial base anchored to the substrate by a basal stroma of minute cells. Asci clavate, (69)75-97(-120) x (11-)11.7-17(-27) µm, apex simple, 8-spored. Ascospores ellipsoidal to fusiform, (22-)23.5-30(-37.8) x (4.4-)5.6-7.3(-9) µm, equally 2-celled, not constricted at the septum, striate, pale tan in mass, colorless by transmitted light in water, 3% KOH, and lactic acid, striate, biseriate, completely filling each ascus.
Characteristics in Culture. Colonies grown 14-21 days at 18-20°C, diffuse daylight. CMD: colonies 2-4 cm diam., flat, white to red-brown, sometimes with a red-brown pigment spreading through the medium, transparent, aerial mycelium dense in the center, scant elsewhere, margin entire to scalloped. PDA: colonies 2.5-7.5 cm diam., flat, tan with brown pigment in the medium, opaque, aerial mycelium felty, hyphae short, margin scalloped to deeply dissected. Conidia forming in small numbers on CMD and PDA. Conidiophores arising from a (3-)4-6(-7) µm wide hypha, macronematous, mononematous, 1-9-septate, (80)120-190(-210) µm long x 4.3-6.7 µm wide at base, straight, smooth, monophialidic. Phialides (57-)70-95(-115) µm long x (2.2-)3-4(-4.5) µm wide at the tip, monoblastic, straight, smooth, tip with periclinal thickening, collarette not flared. Conidia oblong to ellipsoidal, (9-)13.3-19.8(-26) x 5.3-7(-8) µm, with a slightly protuberant, broad, flat, basal abscission scar, unicellular, colorless, smooth, in a drop of colorless liquid at the tip of each phialide. Habitat. On decaying palm fronds.

Known Distribution. New Zealand, Indonesia (North Sulawesi).

Nectria arenulae Berk. et Broome, et N. arenuloidea Samuels similis sed ascosporae (22-)23.5-30(-37.8) x (4.4-)5.6-7.3(-9) µm et conidia (9)13.3-19.8(-26) x 5.3-7(-8) µm.
Status anamorphicus: Acremonium sp. Holotypus: PDD 45718.

Notes. Ascospores (99) of the New Zealand collections are larger [(24)25.4-31.2(-37.8) x 5.8-7.5(-9) µm] than ascospores (54) of the Indonesian collections [(22-)22.3-25.4(-27.5) x (4.4)5.5-6.7(-7) µm]. One New Zealand collection (PDD 46926) had exceptionally large ascospores (22) [(22.5)29-35(-37.8) x (7.2-)7.4-8.6(-9) µm.]. In all other respects the New Zealand and Indonesian populations are identical.
Nectria macrarenula is very closely related to N. arenuloides Samuels (Samuels, 1976b), a species that has smaller conidia and ascospores and that is found on herbaceous substrates.

Holotype. NEW ZEALAND. NORTH ISLAND. Auckland: Waitemata City, Waitakere Ranges, Cascades, on Rhopalostylis sapida Wendl. & Drude., Samuels (81-78), Johnston & Horak 7 May 1981 (PDD 45718; isotype, NY).