Shumilovskikh et al 2015a: Pollen infected by dark-coloured hyphae are pollen grains, the apertures and/or insides of which are covered by dark-coloured fungal hyphae or are filled by pigmented fungal spores.
Shumilovskikh et al 2015b: Fungal infection by dematiaceous (dark-colored) hyphae is documented in our material for pollen of gymnosperms and angiosperms as well as for spores of ferns and of Sphagnum. The observed hyphae are concentrated in the aperture areas. In Angiosperm pollen, these are pores and/or colpi; thin regions in the pollen wall are supposed to be passed by the germination tube and therefore not entirely covered by the very inert sporopollenin layer of the outer pollen wall. In the gymnosperm pollen of Pinus and Picea, aperturoid areas and major occurrence of hyphae are located at the distal side between the two air-sacs of the pollen grains. From there hyphae often grow into the air-sacs. In angiosperms, the main hyphal concentrations are in the pore areas of Alnus, Corylus, Tilia, Matricaria-type and C. vulgaris. In an initial stage, the presence of dark-brown hyphae in the apertures of yellowish pollen grains is typical. Progressive infection is characterized by a developed dark-brown layer inside the pollen grains. The hyphal attack of Sphagnum spores occurs through the trilete mark, the region of spore germination.
Shumilovskikh LS, Schlütz F, Achterberg I, Bauerochse A, Leuschner HH (2015) The development of the raised bog “Borsteler Moor” (Lower Saxony, Germany) based on non-pollen palynomorph data. Studia Quaternaria 32: 5-18.