Pine

Pine pollen is dramatic — you can literally see yellow clouds of it — but it's actually less allergenic than most other tree pollens. The grains are very large (45-65 micrometres) with distinctive air bladders that help them travel long distances. Because the grains are so large, they're less likely to penetrate deep into the respiratory tract. However, the sheer volume of pine pollen can irritate anyone.

If you're allergic to pine pollen, you may also react to:

• Spruce
• Fir
• Other conifers (limited cross-reactivity)

• Don't be fooled by the dramatic yellow clouds — pine is actually less allergenic than invisible pollens like ragweed.
• If pine makes you sneeze, it's likely the volume and physical irritation rather than a true allergic reaction.
• The yellow coating on everything outdoors during pine season is annoying but relatively harmless.
• True pine allergy is rare but does exist — if symptoms are severe during pine season, get tested.