False-colour scanning electron micrograph (SEM) of two pollen grains of cocksfoot grass, Dactylis glomerata, a major cause of hay fever (allergic rhin

---

False-colour scanning electron micrograph (SEM) of two pollen grains of cocksfoot grass, Dactylis glomerata, a major cause of hay fever (allergic rhinitis). The pit on the right-hand grain is the germination pore, out which the pollen tube grows. Cocksfoot pollen is a wind-dispersed summer pollen. Hay fever sufferers produce a sensitising antibody, immunoglobin E (IgE), which attaches to cells in the nose & eyes. It reacts with inhaled pollen, causing the release of various chemicals including histamine. Histamine causes the mucous membranes of the nose, eyes, & throat to swell & become inflamed, bringing on the symptoms of hay fever. Magnification: x570 at size. JBU colouring: blue & orange. BW original is B786/073.

---

Size: 4309px × 3344px
Photo credit: © DR JEREMY BURGESS/SCIENCE PHOTO LIBRARY / Alamy / Afripics
License: Licensed
Model Released: No

Keywords: allergen, allergic, allergy, botany, causing, circular, cocksfoot, coloured, colouring, dactylis, fever, germinating, glomerata, grains, grass, hay, hayfever, jbu, nature, plant, plants, pollen, pollinosis, pore, reproduction, reproductive, rhinitis, sem, spherical