Monographs Details: Nectria gossypina Samuels & Rogerson
Authority: Samuels, Gary J. & Rogerson, Clark T. 1990. New ascomycetes from the Guayana Highland. Mem. New York Bot. Gard. 64: 165-183.
Family:Nectriaceae
Description:Species Description - Perithecia globosa vel subglobosa, 270-350 (-450) µm diam., nonpapillata, aurantia, in acido lactico lutescens, in hyphis albis insidentia. Asci saccati, 40-50 x 8.5-12.5 µm, evanescentes. Ascosporae oblongae vel ellipsoideae, (10-)11- 13.3(-14.3) X (3-)3.4-4.2(-4.3) µm,2-cellulares, laeves, hyalineae. Perithecia globose to subglobose, 270-350 (-450) µm diam., nonpapillate, not collapsed when dry, orange, not changing color in 3 % K O H , yellow in 100% lactic acid, completely covered with a thick mantle of white hyphae with perithecial apex free, cespitose in effused to tuberculate, erumpent aggregates of 10-50 with outlines of individual perithecia obscure, hyphae growing a short distance away from the aggregates. Hyphal mantle 20-50 µm wide; hyphae 2-5 µm wide, septate, branched, smooth, thinwalled, loosely disposed and with many free ends away from the perithecial wall, dense adjacent

Distribution and Ecology - Bark of dicotyledonous trees. Venezuela, Guyana, French Guiana.

Discussion:

Status Anamorphicus: Acremonium/ Verticillium, conidia eseptata, (4.5-)5.6-8.9(-10.8) x (1.8-) 2.4-3.4(-3.6) ixm, conidiophorae pauciramosae.

Hab.: In cortex.

Holotypus: French Guiana (Samuels 5978, N Y )

Anamorph: Acremonium/Verticillium

Characteristics in Culture. Colonies grown 10 days at 20°C, diffuse daylight, on commeal dextrose agar (Difco) 2 cm diam., flat, white, transparent, with aerial mycelium scant or lacking. Conidiophores mononematous or held in pionnotes, 70-100 µm long, straight, smooth, colorless, unbranched and monophialidic or verticillately branched, each branch bearing a single phialide. Phialides 20-55 µm long, 1.8-2 µm at base, 1.5-1.8 µm at tip, collarette slightly thickened, flared or not. Conidia oblong, (4.5-)5.6- 8.9(-10.8) X (1.8-)2.4-3.4(-3.6) µm, aseptate, with or without a slightly protuberant basal abscission scar, colorless, held in colorless slime

Habitat. Bark of dicotyledonous trees.

Etymology of the Specific Epithet. Gossypinus refers to the white hyphae that enclose the perithecial aggregates.

TYPE. FRENCH GUIANA. Upper Marouini River, 2 k m N of Oumanfou-Langasoula, 02º24' N, 54º00'W, elev. 150 m, on bark of recently dead tree, 23,24 Aug 1987, Samuels (5978), deGramille, AUorge, Hahn, Hoff & Weitzman (holotype N Y , isotype CAY). Paratypes. VENEZUELA. Amazonas: Dpto. Rio Negro, Cerro de la Neblina, along Rio Mawarinuma, just outside Cafion Grande, vie. Neblina Base Camp, 00°50'N, 66nO'W, elev. ca. 140 m, on bark, Samuels 7772 (NY, VEN).

GUYANA. Cuyuni-Mazaruni Region, VII: Mazaruni Subregion, VII-2, foothills immediately S of Mt. Ayanganna, ca. 1 k m W of Pong River, 05°28'N, 60º04'W, elev. 550-650 m, on bark of recently dead tree, Samuels (4830), Pipoly, Gharbarran, Chin & Edwards (BRG, NY).

Notes. Nectria gossypina superficially resembles N. subfalcata Henn., but the two are easily distinguished through perithecial anatomy and ascospore morphology. There are no obvious relatives for N. gossypina in Nectria; the rather wide perithecial waU formed of circular to angular ceUs, the oblong, obtuse ascospores, and the Acremonium anamorph recall the N. peziza (Tode: Fr.) Fr.-Group (Samuels, 1976), but perithecia of species of that group do not become yellow in lactic acid and the Acremonium anamorph has unbranched conidiophores. Nectria gossypina is unusual for its stroma, which is formed of loosely intertwined hyphae that emerge through the bark. The anamorph of this species is morphologically intermediate between Acremonium and Verticillium. A n anamorph simUar to that formed in culture was found on the holotype specimen (Fig. 32).