Celtis australis
species: Celtis australis (Nettle Tree, Hackberry)
plant family: Ulmaceae
at aerobiological analyses usually achieved determination level: Celtis, Ulmaceae
photos:
© Biologisches Labor, Umweltagentur Bozen (Italy)
description:
outline: irregular circular to elliptical
size: polar axis: 30.8 (27-35) µm, very changeable
apertures: tri- to penta-zonoporate, pori about 2-3 µm wide, with dots of remnants from the exine.
pollen wall: thin, scabrate exine, thin intine, thickened to onci underneath the pori.
note: granular cytoplasm, containing numerous leucoplasts sized about 1-2 µm.
remarks to the plant:
Hackberry is a wind-pollinated Mediterranean tree or shrub, growing spontaneous on dry, rocky slopes on hot places. It is often planted as an ornamental as it is resistant to air pollution and long-living. Leaves are hairy on both sides, broad-lanceolate setose to caudate and clear serrate. Long-stalked inconspicious flowers open at the same time as leaves unfold from end of March to May. Male flowers appear in pauci-floral racemes, bisexual flowers stand singular basal next to the stem. A reddish-brown to black fruit contains a stone and (edible) fruit flesh.
