(sagebrush [woody] or wormwood [herbaceous])
Pollen light micrograph:
The Artemisia pollen type is routinely distinguished from other
pollen produced by members of the sunflower (Asteraceae or Compositae)
plant family. Artemisia is a tricolporate, echinate pollen grain
recognized by its thick,tapered wall with large collemella,
The foot layer and tectum are of uniform thickness, but
the layer of thick columellae usually tapers toward the furrows (colpi).
The short spines are hard to see with light microscopy, typically they
are less prominent than the large collumella in plan view. The spines
and rods may interact to produce a reticulate patter in light microscopy.
Pollen scanning electron micrograph (SEM)
The furrow membrane is smooth, and the pore circular. The spines
are very short, and widely and evenly placed. In Tranmission Electron
Microscopy (TEM) the wall can be seen to be comprised of an outer layer
(tectum) T of thin branching collumella overlaying
an inner layer of thick collumella C,
and a thick foot layer F.
Production and Dispersal:
Production is moderate and dispersal good. Production by woody
taxa (sagebrush) seems to be much greater than for herbacious
Preservation of the thick walls is good, and the characteristic
shape is easy to recognize in poorly-preserved samples.