Peter Williams has let me have these fine pictures of Tulipa clusiana. They were taken in his greenhouse at ten minute intervals. As the morning temperature rises they open extremely rapidly, presenting themselves for potential insect pollination. Later in the day when temperatures fall or light fades, they close. This plant movement is an example of thermonasty, a plant movement in response to temperature. Lady-tulips can be seen outside in their full glory at Peter’s Open Day tomorrow!
My own naturalised tulip, ‘Little Beauty’ is also thermonastic. Personally, I like tulips in tight bud when they do not open at all on a dull rainy day.
|Naturalised from self sown seed|
|Later in the day|