Phylloblastia fortuita
Phylloblastia fortuita is a species of foliicolous lichen in the family Verrucariaceae. Found in Western Europe and North America, it was formally described as a new species in 2009 by Esteve Llop and Antonio Gómez-Bolea. The type specimen was collected from Sant Medir at an altitude of, where it was found growing on the leaves of Ilex aquifolium. The lichen, originally documented as occurring in the Mediterranean climate of the Iberian Peninsula, was reported from Marin County, California, in 2016. Other plants from which it has been documented include Buxus sempervirens, Hedera helix, Quercus ilex, and, in North America, Sequoia sempervirens.
Description
The thallus of Phylloblastia fortuita appears scattered across leaf surfaces, forming a thin, diffuse, cobweb-like structure with a greenish-grey colouration. The thallus develops more prominently around reproductive structures and consists of clear, interwoven fungal threads measuring 3-4 micrometers in thickness. The is, with algal cells 6–10 micrometres in diameter that form irregular to rounded clusters surrounded by fungal hyphae.The reproductive structures are, more or less spherical to hemispherical in shape, with flattened or depressed tops. These measure 0.1–0.2 mm in diameter and up to 0.1 mm in height, with colouration ranging from greyish brown to dark brown and featuring a felt-like outer surface texture. The perithecia lack an .
The measures 18–32 micrometers thick, with two distinct layers. The outer layer resembles a textura globularis with an olivaceous-brown colour, while the inner layer consists of compressed, elongated cells in a arrangement forming a textura angularis. While paraphyses are absent, are consistently present, appearing colourless with a basal layer of roughly equal-diameter cells and 1–2 oblong apical cells.
The asci are club to egg-shaped, each containing 8 spores, measuring 40–60 by 15–20 μm, with slightly thickened tips that do not react with iodine stain. The ascospores are ellipsoid to with rounded ends, straight to slightly curved, with a somewhat structure. They typically have 5–9 transverse septa and 1–6 longitudinal septa, except in the end cells, with slight constrictions at the septa. They typically measure 20–35 by 5–9 μm, being 3–5 times longer than wide. No pycnidia have been observed in this species.