Details about map content are available here Click on the map dots to view record details.
Species Information
Summary: This is one of the species of Exobasidium that affects plants of the family Ericaceae, this species infecting plant shoots and causing leaves to be red on the upper side and felty dull light green on lower side. Savile''s description is from collections on Vaccinium uliginosum.
It has been reported at least from WA (Burt), and BC (Ginns) and Savile examined collections from NL, NU, QC, and Sweden, but Nannfeldt''s work on Exobasidium species in Europe means that records need to be reassessed.
Fruiting body: infects plant shoots, causing the leaves to become larger or smaller and to roll under from the margins, becoming purple-red to light wine-red, especially towards tips; the lower leaf surface, covered with white spore-bearing tissue appears dull light green, (Breitenbach), parasitic, producing shoot galls with all the later leaves of the gall red on the upper side and felty below, but slightly if at all deformed, spore bearing surface growing flat over the whole lower surface of the leaves, 30-45 microns thick, felty, (Burt), fruits evenly over lower surface, causing leaves to be large, flat, and red on upper surface, (Savile)
Microscopic: spores 20-22 x 8-10 microns, elliptic-cylindric, smooth, inamyloid, colorless, some with droplets of granular contents; basidia 2-spored, 70-80 x 8-10 microns, cylindric to cylindric-clavate, without basal clamp connection; cystidia not seen; hyphae 1.5-3 microns wide, without clamp connections, (Breitenbach), spores 16-20 x 7-8 microns, curved toward the base, colorless; basidia 2-spored, fructification 30-45 microns thick, consisting of large basidia arranged side by side, (Burt), spores 15.5-22.5 x 7.3-9.0(11.5) microns, broadly clavate to elliptic "with hilum bluntly rounded and not prominent, never septate"; basidia projecting about 25-32 microns beyond cuticle, about 9.0-10.0 microns wide, with 2 (rarely 3) sterigmata up to 7.0 microns long x 1.8-2.5 microns wide at base; conidia absent, (Savile)
Habitat / Range
on Vaccinium uliginosum (bog bilberry), (Breitenbach), reported on Vaccinium uliginosum in YT, V. caespitosum (dwarf bilberry) in BC, (Ginns who notes that redisposition of records needs to occur as a result of Nannfeldt''s work on European Exobasidium species), on Vaccinium membranaceum, in WA, V. uliginosum and V. myrtillus in Europe, (Burt), collections examined from Ledum groenlandicum, Vaccinium myrtillus, Vaccinium uliginosum, (Savile)
Similar Species
Exobasidium vaccinii has smaller, nearly cylindric spores, borne on (2)3-6(8)-spored basidia, (Savile). Exobasidium dimorphosporum is similar but spores of two forms: either 13.0-18.5 x 6.5-8.5 with inconspicuous hilum or 18.5-28.5(32.0) x 5.0-7.0(8.0) microns with hooked hilum, 0(1)-septate. The broad spores are somewhat too short and the narrow ones are too narrow and too long for E. vaccinii-uliginosi. (Savile). Exobasidium cordilleranum has smaller spores and has conidia (Savile). Exobasidium phyllodoces has smaller spores and basidia and collections were on Phyllodoce empetriformis. (Savile). Exobasidium empetri has smaller spores which are frequently 1-septate, and fruits on Empetrum nigrum. (Savile).
