This is a challenging time of year to write a nature blog. Trees have gone dormant; their once colorful leaves are but a distant memory. The flowers of spring, summer and fall are nonexistent except for dried seed hoping to be transported on the wind to begin anew in another location. Nature’s reproduction system at work…

Not far from where I live are several Sweet Gum (Liquidambar styraciflua) trees. They are rather barren looking this time of year, as are most deciduous trees. Leaves are long gone, although branches create a natural artwork of its own. At first glance one might think the Sweet Gum could be almost any tree species. Nothing out of the ordinary until you look a bit more closely.

Seed pods hang precariously on its branches. In late fall/early winter seed pods are a warm dark brown, some having already dispersed their seeds.

Pods are sharp, prickly little things to the touch with what appears to have numerous little projections that are visually similar (at least to me) to the beaks of some seed-eating birds. And within that “beak” is a dark open hole. Seed pods may only be an inch and a half in diameter at most. It’s absolutely miraculous, don’t you think? Such intricate tiny detail, almost as if carved by hand. Here’s an up-close look.

Within those holes can be one or two seeds hiding away until they reach their maturity and escape their pod protection. The seeds are winged at one end which allow them to float on the wind and find a place they can take root and grow.

Seeds are small – perhaps just 3/8″ long and less than 1/8″ wide. Not all seeds make it to the ground to take root, as they are eaten by finches, towhees, nuthatches, Carolina wrens, chickadees, yellow-bellied sapsuckers, as well as squirrels and chipmunks. With that many seed “predators” it takes a lot for a Sweet Gum seed to actually sprout and develop into a sapling. A seed pod can have 40 or more seeds within it, depending upon the overall size of the pod. But not all of the seeds are fully developed. Immature seeds can look more like sawdust, as I found out when I left two pods drying on my desk.

Sweet gum seed pods have an interesting growth timeline and one most people never notice until they see the pods on the ground in the fall. It begins in the Spring when small green flowers appear. Trees are monoecious, which means they have both male (staminate) and female (pistillate) flowers. Male flowers are a yellow-green and grow typically on the upper side of a branch, while female flowers are green, smaller and grow on the lower side of a branch.

Wind helps pollinate the flowers which continue to grow throughout the summer and become a green hardened ball in late summer-early fall. The green balls turn brown and mature, eventually dropping seeds to fly away on the wind. However, it takes 20 to 30 years for a tree to be mature enough to produce flowers.

It’s easy to recognize a Sweet Gum tree with its five-to-seven sharply-pointed leaves which resemble a star. In the fall their leaves can turn spectacular shades of yellow, orange, red and even purple. Trees can grow to be up to about 70 feet in height though I’ve read some can be taller when growing in the wild.

This tree can be a host to more than 30 kinds of moths and butterflies including the Luna moth (photo below).

The Luna moth has a wingspan of about 4″ and is a spectacular moth to see with its vivid green coloring and tinges of pink/burgundy along wing edges. The Sweet Gum tree (along with Walnut, Hickory and Persimmon trees) are host trees for the Luna moth. Luna moth caterpillars eat the foliage and eventually pupate into a silken cocoon from which it emerges. It does not have a mouth and does not eat as an adult moth. Its sole purpose is to mate and produce eggs before it dies in about a week.

So next time you see a Sweet Gum tree, I hope you glance up into its branches and look for seed pods and recognize the importance of this tree to butterflies, moths and our natural world. I hope you find the seed pod to be as interesting and fascinating as I have.

Until next time, keep exploring nature up close.