Exobasidium andromedae

Exobasidium splendidum

Exobasidium savilei

Exobasidium rhododendri

Exobasidium hypogenum

Exobasidium cassiopes

Exobasidium vaccinii

Exobasidium vaccinii-uliginosi

Exobasidium japonicum

Exobasidium expansum

Exobasidium uvae-ursi

Exobasidium juelianum

Exobasidium ledi

Exobasidium rostrupii

Exobasidium sydowianum

Exobasidium myrtilli

[Nannfeldt, working from observations in Richards 1896, wrote of E. andromedae having two, or even three, seasonal generations on different organs of L. ligustrina in N. America. The spring generation produces "giant bag-galls," which are followed by leaf-concavity galls. Finally, leaf-spot galls may appear near the end of the season. p.7] 

Infected shoots clustered or more rarely scattered or solitary, slightly elongated. Leaves moderately enlarged, especially lengthwise, soft with revolute margins, splendidly red all over, [becoming?] chalk-white ... and ... hymenium-clad beneath. 

On Chamaedaphne calyculata:
Annual shoots, mostly gregarious from adjoining axils. Leaves moderately enlarged, whitish to red above. 

Conspicuous, subglobose, fleshy, chlorophyll-less, often red gall apples, up to 3 cm. across, with narrow base . . . 

Infected shoots scattered, slightly elongated with distinct, sparsely hairy internodes. Leaves much enlarged (up to 10 x 6 mm.), triangular with distinct, hastate base, soft, thin and flat with revolute margin, spreading or slightly reflexed (never appressed), blood-red or whitish (very rarely pink) above (color depending on the host-individual ... ), eventually hymenium-clad beneath.

Infected shoots scattered, pale all over (greenish to pinkish white) with glabrous elongated internodes and only indistinctly set-off leaf-pairs. Leaves malformed (up to 6 x 3 mm), mostly subcylindric, spreading, like the stem eventually hymenium-clad, but apical or marginal parts (especially of the lower leaves) not rarely of normal shape, structure and colour and remaining hymenium-less ... 

In Fennoscandia ... very common on C. tetragona, occurs mostly together with E. hypogenum and seems to be the more abundant of them ... 

it seems justified to combine this tetragona parasite with E. cassiopes, originally described on C. mertensia ...

Circumscribed. Mostly conspicuous and much thickened leaf-concavities, c. 1 cm. across, bright red and yellow-margined above, pinkish white, eventually hymenium-clad and chalk-white beneath. Sometimes mere leaf-spots; occasionally strongly hypertrophied and badly malformed flower-buds or shoot-tips. 

Infected shoots mostly scattered, only a little elongated. Leaves moderately to strongly enlarged, not or only slightly thickened, yellowish white or pale to bright red above (depending on light?), eventually chalk-white, densely and continuously hymenium-clad beneath. 

This species causes a well-known and much studied disease on the horticultural "azaleas." Numerous (all?) cultivars are more or less susceptible ...

Entire leaves or parts deformed into very conspicuous, pale, fleshy, shapeless galls up to 3 cm across, eventually hymenium-clad and chalky white on the morphological underside. 

[I]nfecting major branch-complexes or entire stems but, as it seems, never passing through subterranean parts from one stem to another. Branching only little influenced. Leaves mostly slightly diminished, pale green to (in strong light?) often reddish, often mottled above and eventually hymenium-clad and chalk-white between the well-marked naked nerves beneath.[At times] leaves somewhat enlarged ... 

Dense ... clusters of infected annual shoots, tending to be orthotropic ... Leaves thin, soft, dark purple, eventually hymenium-clad beneath between the nerves, hymenium not continuous, individual fascicles distinctly visible. The upper epidermis of the leaf not invaded by the fungus ...

The whole host-plant as a rule strongly dwarfed and richly branched. Leaves thin, soft and flat with distinctly crenulate margin, bright red, eventually hymenium-clad between the nerves beneath. 

Very inconspicuous, pale (mostly yellowish) leaf-concavities or hardly thickened leaf spots up to about 1/2 cm across, eventually hymenium-clad beneath.

Leaf-spots very small, only rarely more than 3 mm in diam., hardly thickened, reddish above, eventually thinly hymenium-clad beneath. 

Leaf spots small, c. 1/2 cm across, rarely more, in heavy attacks often confluent, not or only moderately thickened, at first bright red above with broad yellowish margin, cuticle soon flaking off, especially from the upper surface, which then turns orange brown and slightly glossy as if greasy, eventually sparsely hymenium-clad beneath. Exceptionally, single annual shoots become wholly diseased with leaves dark purple, simulating such diseased by E. uvae-ursi. Leaf-spots and diseased leaves with hyphal palisade between epidermis cells also on upper side.

Systemic. Stems and ramification as a rule only slightly changed; branches perhaps a little prolonged and more upright than normal. Leaves only slightly enlarged and thickened, often bullate, yellowish green to bright red above (depending upon light?), eventually hymenium-clad between the nerves beneath. Rarely whole plants strongly dwarfed with dwarfed leaves, richly and spreadingly ramified and red all over. 

Exobasidium, a taxonomic reassessment applied to the European species