page_title: Phyllactinia guttata
section_title: Description
hierarchical_section_title: Phyllactinia guttata / Description
caption_attribution_description: English: The powdery mildew species Phyllactinia guttata (Wallr.) Lév. Microscopic view of cleistothecium with appendages with bulbous base.
context_page_description: Phyllactinia guttata is a species of fungus in the family Erysiphaceae; the anamorph of this species is Ovulariopsis moricola. A plant pathogen distributed in temperate regions, P. guttata causes a powdery mildew on leaves and stems on a broad range of host plants; many records of infection are from Corylus species, like filbert and hazel. Once thought to be conspecific with Phyllactinia chorisiae, a 1997 study proved that they are in fact separate species.
  Microscopically, P. guttata is characterized by large ascomata, long narrow pointed appendages with bulbous swellings at base, 2- or 3-spored asci with large ascospores; the ascomata also have gelatinous cells with tufts of hyphae somewhat resembling hairs. The cleistothecia are capable of dissemination and attachment to new growing surfaces by means of gelatinous penicillate cells.
context_section_description: The mycelium may be abundant and persistent, or scant and short-lived (evanescent). The cleistothecia can become large (216–245 μm), with soft wall tissue, and obscure  cellular structure and cracks and wrinkles (reticulations).
  The cleistothecia typically develop 8–12 easily detachable hyaline appendages that vary in length from 191–290 μm long. The asci are 4 to 5 to 20 or more, ovate, supported by small stalk-like structures (pedicellate), with dimensions of 72–83 by 32–40 μm. There are typically 2 spores per ascus, sometimes 3 or 4, and they are 31–36 by 21–25 μm.
  The cells attached to the upper part of the ascomata that resemble hairs are known as penicillate cells; they are made of foots and filaments. The filaments can gelatinize by absorbing water and are thought to function in helping the ascomata adhere to the surface on which they grow, like the underside of leaves. In P. guttata, the foots are cylindrical, irregular in width, 32–72 by 7.5–25 μm, and divided into 2–10 branchlets in the upper part. Each branchlet is short, bulbous, with filaments being 20–42 μm, somewhat shorter than the foots, which are 2–4 μm wide. The short, bulbous branchlets on the multi-branched upper part of the foots are unique among the Phyllactinia and are a distinguishing taxonomic characteristic of this species.
caption: Microscopic view of cleistothecium showing appendages with bulbous base
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