Pollenatlas

species: Fagus sylvatica (Beech)
plant family: Fagaceae
at aerobiological analyses usually achieved determination level: Fagus, (Fagaceae)

photos: Landesagentur für Umwelt, Bozen (Italy)

description:
outline: more or less circular
size: polar axis: 44.6 (41-47) µm, equatorial axis 47.8 (45-52) µm
apertures: tricolporate pollen with more or less short, acute colpi and distinct pori (about 9-11 µm in diameter), sometimes exine leftovers are visible at the margin of the pori
pollen wall: thin, scabrate to rugulate exine, slightly thickening around the pori. Thin intine protrudes in the area of the pori.
additional remarks: granular cell plasma

remarks to the plant:
Beech is plainly the typical European tree, growing preferably on well-drained soils. It is a large deciduous tree, up to 40 m or more of height, with smooth greyish bark. The leaves are untoothed, elliptical-ovate, and silky hairy when young. Adolescence and thus flowering of the trees begins with an age of 40-60 years. Male flowers appear concurrently with leaf bud break in April/May in long-stalked, rounded clusters, females in short-stalked clusters, surrounded by scaly bracts.

species: Fraxinus excelsior (Ash)
plant family: Oleaceae
at aerobiological analyses usually achieved determination level: Fraxinus excelsior, Fraxinus, (Oleaceae)

photos: Landesagentur für Umwelt, Bozen (Italy)

description:
outline: circular or rounded triangular in polar view, oval in equatorial view
size: polar axis: 22.5 (20-24) µm, equatorial axis 26.7 (24-28) µm
apertures: tricolpate (seldom tetracolpate) pollen with long, narrow, acute colpi
pollen wall: thin, reticulate exine, muri appear dotted in lines (like a cord of pearls). Lumina of the fine reticulum of variable width, but not diminishing towards the margins of the colpi. Thin intine with flat germination areas.
additional remarks: the pollen grain has a tendency to permit staining only very feebly

remarks to the plant:
Ash grows widespread and common in woods, scrub and hedgerows, often on calcareous soils and preferably at the side of flowing waters. It is a wind-pollinated, deciduous tree with opposite, pinnate leaves composed of 7-13 ovate, toothed leaflets. Even in winter ash is easily recognizable by its black buds. Flowers come up in clusters of male, female or mixed, appearing before leaves. Petals and sepals are absent, stamens in purplish tufts. Fruit are stalked and winged. Flowering time is March to May.

species: Fraxinus ornus (Manna-ash)
plant family: Oleaceae
at aerobiological analyses usually achieved determination level: Fraxinus ornus, Fraxinus, (Oleaceae)

photos: Landesagentur für Umwelt, Bozen (Italy)

description:
outline: mostly circular, seldom rounded triangular in polar view, oval or circular in equatorial view
size: polar axis: 20.1 (18-22) µm, equatorial axis 22.6 (21-24) µm
apertures: tricolporate pollen with very long, spindle-shaped colpi and lolongate, often almost invisible pori
pollen wall: reticulate exine, exine cross section and network width reducing towards the openings. Muri appear dotted in lines (like a cord of pearls) in top view. Membranes of the openings contain often fine exine remnants. Intine forms frequently flat germination areas (onci).
note: similar pollen in Olea europaea

remarks to the plant:
Manna-ash is probably a south European – west Asian plant. It is widespread in the Mediterranean, extending into the central Alps along the major valleys. The deciduous, thermophilous tree grows in scrubs and sunny forests, occasionally also spontaneous or planted as ornamental. Leaves are pinnate with ovate-lanceolate leaflets. The white, fragrant flowers are united in terminal erect clusters. They appear together with the leaves between April and beginning of June. Manna-ash produces no nectar, but plenty of pollen for various insect visitors.