Box elder trees are members of the maple family and their sap flows too. You can even make maple syrup from box elders. This particular tree has several broken branches that were probably nipped off by squirrels. The sap leaking out of the ends of the branches froze into icicles. These sapcicles taste sweet if you break them off. American Indians were probably the first to encounter sapcicles and this discovery may very well be how humans first clued into how to make maple syrup.
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