Peucedanum venetum:en
Pollen (tricolporate): Size 25 (22.4-26.1); 14 (11.6-15.5) μm. Polygonal or slightly triangular, prolate (PoFormI ca. 1.66-2.07), tricolporate, isopolar, verrucate. Aperture membranes are not ornamented. Long colpi.
Pollen (bicolporate, twin-mutation): Size: 24 (20.0-27.8) μm; 15 (13.1-16.7) μm. Rectangular to ovale, prolate (PoFormI ca. 1.40-1.93), dicolporate, heteropolar, verrucate. Aperture membranes are not ornamented. Long colpi. Pore diameter about 3.2 (2.9-3.7) μm. After a new sampling, no bicolporate pollen could be found any more.
Abstract: Peucedanum venetum belongs to the family of the Apiaceae. This family shows a very characteristic rod-shaped (prolate) pollen with three germination openings (tricolporate). In polar view the shape of this pollen is slightly triangular. In pollen samples of this species, pollen very different from the basic form of the Apiaceae was found. These samples were prolate also but showed only two germination openings (dicolporate). In polar view the outline was elliptic with distinct constrictions on the two longer sides. This deviation of the usual pollen form might be triggered by local mutations or by disturbances during pollen development.
See also: Ungewöhnliche Pollenform bei Peucedanum venetum, Zeitschrift "Mikroskopie", Nr. 1, 2017, S. 40-43
Rundliche bis ovale Apertur. Direkte Oeffnung in der Exine.