Bloemstigmas

Bloemstigmas, or flower stigmas, are the receptive surfaces at the tip of the pistil in flowering plants. They are the first contact point for pollen grains carried by wind, water, or pollinators and play a central role in fertilization. Located at the top of the style, above the ovary, stigmas vary in shape and surface texture but share the function of capturing pollen and supporting the germination of pollen grains and the growth of pollen tubes toward the ovules.

Structure and variation: stigmas can be dry or wet. Dry stigmas typically have a rough or papillate surface and rely on specialized epidermal cells to capture pollen. Wet stigmas are sticky or moist and may secrete mucilage to trap pollen grains. The surface is often rich in papillae, small protrusions that aid pollen adhesion. Stigma morphology—including lobed, disc-shaped, or elongated forms—varies across plant groups and is often of taxonomic utility.

Function and pollen interaction: upon contact, pollen grains hydrate and germinate on the stigmatic surface, producing pollen tubes that grow through the style to reach the ovules. Stigmas can participate in species-specific pollen recognition, and in some plants, they contribute to self-incompatibility mechanisms that prevent self-fertilization.

Development and ecological context: stigma receptivity is tied to floral development and usually coincides with anthesis. Environmental conditions can influence stigmatic function and pollen performance. In agriculture and horticulture, stigma structure and compatibility affect seed set and hybridization.

This organ’s structure and function reflect adaptations to diverse pollination strategies and are useful in plant taxonomy and breeding studies.