Triporate Types
1. Grain with echinate or reticulate sculpture
2. Grain echinate
3. Tri-lobed, exine between apertures thick and with internal chambers (cavea), spines crowded and broad based
3’ Shape elliptical, exine uniform and without cavea, spines narrow based and scattered, pores abruptly thickened internally
2’ Grain reticulate, apertures surrounded by a broad thickening of mesexine that protrudes internally
1’ Grain psilate
4. Grain sub triangular in shape, pores protruding with large cylindrical or triangular pore cavities, pores with an internal collar or conspicuous thickening of endexine at the pore (Onagraceae)
5. Pore with prominent internal collar, size < 65m or > 100 m
6. Size less than 65 m
6’ Size greater than 100 m, pore opening slit-like, collar fused to wall of pore
Oenothera biennis, Oenothera rhombipetala
5’ Size 60- 75 m, Endexine thickened at pore but not making an internal collar
Epilobium angustifolium, Epilobium stricta (Epilobium coloratum, Epilobium adenocaulon)
4’ Grain sub-triangular to round, pores simple, annulate or protruding but lacking internal collars or thickening of endexine at the pore
7. Diameter 40 to 75 m, pores may be slightly heteropolar
Carya cordiformis, Carya ovata
7’ Diameter <40 m, pores equatorial
8. Pores intruding, shape oblate- rectangular, apertures meridionally elongated
Monotropa hypopithys, (Monotropa uniflora)
8’ Pores protruding or even, shape circular or triangular, apertures circular
9. Pores protruding
10. Pores with a pore cavity created by separation of ektexine and endexine
Betula glandulosa, Betula lutea, Betula papyrifera
10’ Pores without pore cavity
11. Inner surface of pores roughened, exine bent outward to make pore protrude
11’ Inner pore surface smooth, exine thickened at pore
12. Shape triangular
Corylus americana, Corylus cornuta
12’ Shape excluding pores spherical
Carpinus caroliniana, Ostrya virginiana
9’ Pores even with surface of grain
Laportea canadensis
