Tricolpate refers to a subclassification of the "Eudicot" monophyletic group, the "true dicotyledons" (which are distinguished from all other flowering plants by their Tricolpate pollen

Pollen

Pollen is a fine to coarse powder containing the microgametophytes of seed plants, which produce the male gametes . Pollen grains have a hard coat that protects the sperm cells during the process of their movement from the stamens to the pistil of flowering plants or from the male cone to the...

 structure. The number of Pollen grain furrows or pores helps classify the flowering plant

Flowering plant

The flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...

s, with eudicots

Eudicots

Eudicots and Eudicotyledons are botanical terms introduced by Doyle & Hotton to refer to a monophyletic group of flowering plants that had been called tricolpates or non-Magnoliid dicots by previous authors...

 having three colpi (tricolpate), and other groups having one sulcus

Sulcus (anatomy)

A sulcus is a depression or fissure in the surface of an organ, especially the brain.-Elsewhere:* anterior interventricular sulcus* calcaneal sulcus* coronal sulcus* gingival sulcus* gluteal sulcus* interlabial sulci...

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Pollen aperture

Aperture (botany)

Apertures are very small spots on the walls of a pollen, where the wall is thinner and/or softer. For germination it is necessary that the pollen tube can reach out from the inner of the pollen and transport the chromosomes to the egg deep down in the pistil...

s are any modification of the wall of the pollen grain. These modifications include thinning, ridges and pores, they serve as an exit for the pollen contents and allow shrinking and swelling of the grain caused by changes in moisture content. The elongated apertues/ furrows in the pollen grain are called colpi (singular colpus) which along with pores, are a chief criteria for the identifying pollen classes.