// Definition
The hair-like reproductive structures of female cannabis flowers designed to catch pollen for seed production. Non-glandular — they do not contain cannabinoids or produce resin. Often confused with trichomes but serve an entirely different biological function.
// From the Episode
Dr. David Allen asked about tiny structures on stigma hairs that resembled trichomes. Bubbleman clarified through bioassay (isolating and smoking individual plant components) that stigma hairs produce no psychoactive effect. They are a common contaminant in dry sift, causing it not to melt. The tiny structures on stigma hairs are papillae (p-a-p-i-l-a-e), hair-like cells that help catch pollen. Bubbleman's isolation bioassay work confirmed only glandular trichome heads produce the high.