= Stigma
{disambiguate=botany}
The <stigma (botany)> is the <carpel>'s <pollen>-receiving region. Compatible <pollen> may form a <pollen tube> that grows toward an <ovule>; arrival alone does not establish <fertilization>.<Biology 2e by Mary Ann Clark and others/32.2 Pollination and Fertilization>[Biology 2e, §32.2 Incompatibility Genes in Flowers and Double Fertilization]{ref}
A useful diagnostic question is what was actually observed: <pollen> on a <stigma (botany)>, a growing <pollen tube>, or a new <plant embryo>? Each observation tests a different stage. A <pollen tube germination assay> isolates the middle process for direct viewing.
Back to article page
