Additional Specimen Examined. NEW ZEALAND. North Island. AUCKLAND: Waitemata City, Waitakere Ranges, off Mountain Rd., on Nectria tawa Dingley (PDD 18527), Dingley, 16 Sep 1958 (PDD 51331, NY).

Anamorph. Acremonium-like.
Mycelium not evident. Perithecia solitary, superficial, nonstromatic, anchored to substrate by a fringe of white hyphae, pyriform 190-280 (-375) x 150-250(-310) µm, with an acute papilla, smooth, collapsing by lateral pinching when dry; pale yellow, not changing color in 3% KOH. Cells at the surface of the perithecial wall forming textura angularis to textura epidermoidea, with unevenly thickened walls. Perithecial wall 15-30 µm wide, comprising a single region of elliptic, 5-7,um long, indistinct cells. Perithecial papilla formed of a palisade of hyphal elements with tip cells, at exterior, clavate to circular in outline, 7-10 x 5-7 µm, walls ca. 0.5 µm thick; hyphal elements becoming progressively more narrow and thin-walled toward the ostiolar canal and there merging with the periphyses. Asci cylindrical to clavate, (63-)67-75(-90) x 6-8(-9) µm, apex with a ring; 8-spored, ascospores 1-striate throughout or 2-striate above and 1-seriate below. Ascospores ellipsoidal, (8-)8.5-11(-12) x (3-)3.8-4.7(-5) µm, equally 2-celled, not constricted at the septum, coarsely striate, colorless.
Characteristics in Culture. Colonies grown two weeks at 20°C, 12 hours near ultraviolet + cool white fluorescent light. CMD, PDA: barely.growing away from the original inoculum, colony dense, velvety, pale salmon with a strong actinomycetous odor. Conidia forming on CMD and PDA; conidiophores arising from 2-3 µm wide hyphae, macronematous, mononematous, unbranched, smooth, 1-2-septate, (58-)75-132 (-160) µm long x 2-3 µm wide at base, monophialidic. Phialides integrated, terminal, straight, smooth, (13-)25-66(-80) µm long, monoblastic, tip slightly thickened, flared or not, (1.5-)2(-2.5) µm. Conidia cylindrical to naviculate and narrower at tip than at base, with a broad, protuberant basal abscission scar: 0-septate: (10-)11-14.5(-16) x (2.5-)2.7-3.7(-4) µm 1-septate: (14-)14.8-21(-22) x 3-4. µm 2-septate: (17-)18-23(-25) x 3-4 µm 3-septate: (17-)20.5-26 x (3-)3.5-5 µm; held in a single, terminal, colorless drop of slime.

Known Distribution. New Zealand (Auckland).

Habitat. On perithecia of Nectria spp.

Nectriopsidi perpusillae (Mont.) Samuels similis, sed ascospores striatae, (8-)8.5-11(-12) x (3-)3.7-4.7(-5) µm.
Status anamorphicus Acremonium-similis. Holotypus. New Zealand (PDD 41423).

Etymology of the Specific Epithet. Refers to parasitism on a species of a sister genus of the Hypocreales.
Notes. Cultures derived from the holotype are no longer viable. The ring in the apex of asci of PDD 51331 is obscure, far less obvious than it is in asci of the holotype.
Nectriopsis sororicola superficially resembles N. puiggarii and Nectria brunneostriata in forming small yellow perithecia directly on the perithecia of other pyrenomycetes. Nectriopsis albofulta and N. epinectria also have striate ascospores but perithecia of these species form within mycelium on other ascomycetes. Ascospores of Nectria brunneostriata and N. epinectria are distinctly brown.
The anamorph of N. sororicola cannot be unequivocally placed into any described anamorph genus. The phragmosporous conidia borne on phialides indicate Cylindrocarpon or Cephalosporiopsis. Because N. sororicola is unrelated to any of the species of Nectria that have typical Cylindrocarpon anamorphs (Booth, 1966), I do not refer this anamorph to that genus. Cephalosporiopsis and Acremonium, as described, are distinguished through conidial septation; conidia of species of the former are once septate whereas conidia of species of the latter are aseptate. Rossman (1983) emended the concept of Cephalosporiopsis to include the species with phragmosporous conidia that are anamorphs of Nectria arenula (Berk. & Broome) Berk. and its relatives (Rossman, 1983; Samuels, 1978). Nectriopsis sororicola is not closely related to these fungi. The closest relatives of N. sororicola are species of Nectriopsis, and most of the known anamorphs of Nectriopsis are species of Acremonium. In the belief that anamorphs of related teleomorphs are themselves related, in spite of morphological differences, and in the understanding that Acremonium as currently constituted is biologically heterogeneous, I refer the anamorph of N. sororicola to Acremonium.

Holotype. New Zealand. North Island. Auckland: Waitemata City, Titirangi, Titirangi Beach Reserve, on perithecia of Nectria discophora (Mont.) Mont., Samuels, Johnston & Rattray, 10 Dec 1980 (PDD 41423).