A hazelnut tree (this one, a European Corylus avellana, I think), with its strong, narrow, divergent trunks, provides a handy place to lock a bike. After fiddling with lock and keys, I take a closer look at this bike rack of convenience, which is in flower.
Most conspicuous are the male flowers, the dangly yellow catkins. But then another colour catches the eye--tiny female flowers, represented by groupings of extended red pistils, on separate short shoots.Mark's Fruit Crops, hazelnut link,
"Flowering habit is unusual. Both and flowers are initiated the summer prior to harvest. Female flowers lack perianth and ovaries at the time of pollination in mid-January to mid-February; the pollen tube grows to the base of the style and becomes quiescent until 5-6 months later (June), when the ovary and ovule develop. Fertilization then takes place in July, and the nut rapidly develops, maturing by late August. "
How about that. After pollination, fertilization is delayed for several months, during which the incomplete female flower develops further.
There's not a lot to learn from a plain old metal bike rack.
Now leap five months into the future!