March 20, 2015. During my nine-day absence, a green tide has rolled over the swamp. It starts first along the riverbank, where the silver maples are the first hardwood species to leaf out, sometimes in February (but not this year), and along with the willows, sugarberries, box elders, river oats, and other early-leafing riparian vegetation, has cast a bright-green hue to the river corridor.
Spring in the swamp also starts from the ground and works up. The sedge meadows green-up first (some of the sedges have already produced flowers). The quintessential spring flower of Congaree, butterweed (Packera [formerly Senecio] glabellus), is standing tall and offering its yellow blooms to any interested insect pollinator, primarily small bees and flies but on occasion, butterflies. The understory trees of deciduous holly, ironwood, and spicebush are taking advantage of extra sun filtering through from a still- bare canopy to produce flowers and leaves. Pawpaw is also getting into the act with abundant flower-bud production. Its leaves will come later and are so large that they apparently have no problem imbibing enough sunshine through a leafed-out, closed canopy.
On this first day of spring, red maples are starting to leaf out, and young, tender laurel oak leaves are making an appearance to soon replace the recently fallen, mature leaves of last year. Oak catkins are swaying in the breeze, and many ironwood catkins have already produced pollen and fallen to the ground. The thickets and blow-downs are green with the new growth of blackberry briars, and in some unfortunate cases, new growths of Japanese honeysuckle and Chinese privet.
Other signs of spring I observe today on an eight mile, round-trip hike to the river and back are paired-up blue gray gnatcatchers, two calling white-eyed vireos, singing male Northern parula warblers, at least half-a-dozen zebra swallowtails (about half the size of summer specimens), and three question mark butterflies. I also see our state flower, yellow jessamine, in bloom along with a few purple violets and an interesting white violet blooming in the muck swamp which I think is primrose-leaved violet, Viola primulifolia.
On the low boardwalk earlier today I ran into some bat researchers who have been monitoring a large hollow tupelo at the back of Wise Lake supporting a colony of Eastern pipistrelles. The tiny bats have already been making feeding sorties in the warming March air.