Nectria mariae

A little-known species with very few records in the Iberian Peninsula, easily recognised by its host (decaying small twigs of Buxus sempervirens on the ground) and the appearance of the stromata upon drying.

Stromatal surface up to 2.5 mm in diameter, composed of 2 to 15 aggregated perithecia. Perithecia globose to subglobose, 0.3–0.5 mm in diameter, reddish with a darker apical zone.

Outer part of stroma of textura globulosa-angularis, with thick-walled hyphae, yellowish in water mounts under the microscope.

Inner wall of stroma formed by elongated hyphae of textura prismatica with thinner walls; hyphae of the perithecial wall react deep purple in KOH, while superficial hyphae remain yellow.

Asci clavate, 8-spored, irregularly biseriate, measuring 120–150 µm long by 20–23 µm wide, inamyloid in Melzer's reagent.

Ascospores ellipsoidal to fusiform with rounded ends, minutely spinulose-walled, mostly with a prominent median septum, measuring 20–27 µm long by 8–11 µm wide, with a distinct constriction at the septum and faint granular contents inside.

Herbarium material available: JTP1940/23.