tricolpate

Tricolpate describes a type of pollen grain characterized by three apertures, or colpi. These furrows are the sites where the pollen tube emerges during pollen germination. The term comes from Latin tri- meaning three and colpus meaning furrow.

Morphology: In tricolpate pollen, three elongated colpi typically extend from one pole toward the opposite pole, though the precise orientation and length can vary. The exine—the outer wall—may be smooth, porous, or sculptured, often displaying a reticulate or tectate pattern depending on the lineage. The overall shape of the grain ranges from spherical to oblate or elliptical, and the size spans wide across taxa.

Taxonomic significance and distribution: Tricolpate pollen is a hallmark of the core eudicots, a large clade within flowering plants that includes many familiar orders and families. As a diagnostic pollen feature, it is widely used in plant systematics and palynology, including fossil pollen analysis to infer the presence of eudicots in ancient floras. While common among core eudicots, not all eudicots possess tricolpate pollen, and some non-eudicot lineages may exhibit similar aperture patterns.

Examples: In modern flora, many rosids and asterids produce tricolpate pollen. The feature is also observed in numerous extinct taxa used in reconstructing past plant communities.