Sep 11, 2010

early adopters


If you are trying to learn tree identification, certain times of year are better than others. Right now is the time to learn black gum, sourwood, sumac and tuliptree. These trees get a head start on fall, turning colors while the rest of the trees remain green.

Tulips are turning yellow, the others red. Sumac tends toward fiery tones like you might see in a sunset. It also has compound leaves, and if it has produced fruit, the red, conical berry clusters are distinctive. Sourwood takes on regal tones that approach purple.

Black gum has the purest reds. Gums start losing leaves as soon as its fruit ripens, possibly as a signal to birds to come eat. Migrating thrushes are especially fond of black gum fruits. Leaves begin to turn red in August, but it takes weeks for all the leaves to turn, so there are always a few bright red ones on any tree at any point during fall migration.

Right now, all these trees are recognizable at a glance, so it's a good time for roadside dendrology. As you drive around, you can get a sense for how abundant these species are, where they grow and what is distinct about their growth form. As other trees start to turn, new colors will appear and the roster of trees you have learned to identify will get a bit longer.

Sep 7, 2010

milkweeds


Butterfly weed is a native of meadows and clearings. It's rich orange color is among the most spectacular on the Southern Appalachian palette. Because it produces several flower clusters per stalk and they bloom progressively, its hue accentuates our meadows for weeks on end. The plant may even flower twice in good years.

Pollinated flowers turn into okra-like seed pods that break open and release round seeds attached to long, feathery filaments that lift them off on wind gusts. All milkweeds do this, as do many of their relatives. There are 14 species of milkweed known from Tennessee, plus five more in sibling genera. Nationwide, we are home to about a hundred species of milkweed.

Dogbane, another meadow plant, is a close relative, as are persimmons and blueberries. Flowers on that segment of the evolutionary tree tend to be tubular, fleshy and clustered. Seeds are more variable.

Many native pollinators visit butterfly weed flowers, including bees, wasps, beetles, flies and their namesake. Orange butterflies such as monarchs and fritillaries love butterfly weed, whereas tiger swallowtails prefer the pale pink common milkweed often growing nearby.