The dried fruit capsule of the Horse-Chestnut (Aesculus hippocastanum) is distinctively prickly. I just started a class on Native Flora in Winter at the New York Botanical Garden. I hope to share some of what I learn in the coming weeks. Let’s start with: the mints (Lamiaceae) are one of the easiest families to identify in winter; they have square stems, opposite branching, and smell minty-great.
But in the meantime, the horsey Aesculus is generally unmistakable, littering the ground with conkers and spiky capsules. But should you not find any of those trouts in the buttermilk, look to the tree’s bud scars: they are horse-shoe shaped with seven “nails.” This classic park tree is also an introduced species, so it will not be not covered in the course. But I just love those prickly capsules.Here is a North American native, a Kentucky Coffee Tree (Gymnocladus dioicus). But, on 5th Avenue near Green-Wood, somewhat out of its historical Old Northwest range. This youngster probably came from the nursery with this cargo of lichens. Lichens are highly sensitive to air pollution, so, alas, they may not linger on this busy avenue. Note those characteristic long furrows. They won’t be so pronounced in maturity (knock wood), but they certainly are in youth.