February 15 - Tree Expert Visit

​Today we had a wonderful visit from Anne Aldridge, a botanist with the Dumbarton Oaks Park Conservancy who was introduced to us by Brown Room parent Lindsey Milstein. Anne brought lots of twigs from different trees so that we could see their different characteristics. There were evergreen Yew twigs, Red Twig Dogwoods, Box Elders, and Osage Oranges. With Anne’s guidance, we carefully examined the twigs freckles, or lenticels, which help the tree breathe.
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​We noticed the trees’ different branching patterns. Some form two branches opposite each other like shoulders. Some branch out in different directions. Anne and Lindsey cut twigs and scratched off strips of bark so that we could smell the inside of the twigs. Jack observed that one of the twigs was very bendy, Anne explained that this tells us the tree is young. We also noticed that some branches had tiny buds. Some leaf buds and some flower buds.  Anne explained there are lots of characteristics we can observe even in the winter. The color and texture of their bark, the pattern and size of their lenticels as well as their branching pattern, buds, and smell are all features that help us to identify tress and understand their behavior. 

Leigh: It smells like fresh air.

Louise notices branching patterns.

Lindsay shows us tree cutting tools.

​After our discussion we spent time carefully observing and drawing some of Anne’s sample twigs. Sam was very interested in the tiny buds of the Yew. Kian carefully observed the up and down direction of his branch and its tiny leaf buds. 

​After drawing, we headed to the outdoor classroom. We noticed that there are a few evergreens visible from the outdoor classroom and talked about the weeping willow a few yards over. Anne pointed out that it’s possible to see its buds even from this distance. Observing the silvery, flickering appearance of the leaves of one tree fluttering in the breeze, Will said, “It looks like a ghost.” Looking closely at the tress in the outdoor classroom, Anne identified a Witch Hazel, which blooms in the fall and has tiny buds and flowers still visible. She pointed out that the Magnolia has fuzzy flower buds and smooth leaf buds. 

​Back in the classroom, we had lots of questions for Anne. Louise asked “How do the trees grow?” Anne explained that the roots carry water and minerals up from the ground, through the branches to the leaves, which are a kind of “food factory” that takes in carbon dioxide and sunlight and converts them into energy to feed the tree. Elle asked, “Why do the leaves change color?” Anne explained that when cold weather comes, of if there is a drought, the trees protect themselves and conserve energy by shutting down the food factory; it closes of the supply and the leaves fall off. She also explained that sap helps the trees carry water and minerals from the ground to the branches and leaves.  

Thanks to Anne for sharing her knowledge and love of trees, to Lindsey for making the visit possible, and to Gigi for spending time with us.