Monday, February 20, 2023

Yew tree pollination

 February is the month when the tiny male cones of yew trees begin to shed their yellow pollen. These were photographed in Teesdale a couple of days ago. 














Yew trees are dioecious - either male of female - and the male pollen is carried on the wind to single female ovules hidden amongst the foliage on another tree. These are tiny and can be hard to spot, but here is one, ready to receive pollen.














After fertilisation the outer wall of the ovule swells to become a soft, fleshy, aril that surrounds the single hard seed inside. It turns bright red in autumn, to attract the attention of birds. 

Every part of a yew tree, except the aril, is poisonous to humans but thrushes, fieldfares and redwings quickly devour them. Nuthatches extract the hard seed, wedge it into crevices in yew trunks and hammer it open to extract the kernel. There's more about them in this Guardian Country Diary.



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