Tag Archives: botany

The heartbeat of a twig

We mammals tend to regard plants as stationary objects, inert beings that form a backdrop for the more exciting lives of those us of driven by heartbeats and nerves. Here’s some data from a twig on the sugar maple in my backyard that might call us to a more expansive view of our botanical cousins. The graph shows how the diameter of a growing twig changes over a week.

Maple graph

Measurements made by Ecomatik dendrometer

This is the pulse of the tree: one heartbeat every twenty four hours. The twig is fattest at dawn, then the twig shrinks as the water-conducting vessels, the xylem “tubes,” get pulled inward by the draw of passing water. Like a straw that collapses inward under the influence of an enthusiastic drinker, the twig shrinks and reaches its narrowest point in the early afternoon when the leaves are hemorrhaging water to the hot, thirsty sunshine. The twig then gradually swells as the sun lowers and darkness comes. The movement is slight, a few hundredths of a millimeter each day.

Note that the graph shows an upward trend. This young green twig is adding wood, growing day by day.

All around us: every twig throbbing with life.

Bluebell Island…some botanical treasures

The South Cumberland Regional Land Trust trip to Bluebell Island today was a great success. The bluebells are just opening up. A few are in full bloom. The next week promises a fine display.

Some favorite species:

Two rare dwarf trillium were in bloom:

...only ones know to exist anywhere around here.

…these two plants are the only ones known to exist anywhere around here.

Delicious blooms.

Delicious blooms. Pollinators, do your work. Seeds needed.

Also present were both white and yellow trout lilies, growing side by side. Genetic incompatibility keeps them from interbreeding, even if pollen gets mixed up by the work of insouciant bees.

White trout lily: Erythronium albidum

White trout lily: Erythronium albidum

Yellow trout lily: Erythronium americanum

Yellow trout lily: Erythronium americanum

Thank you, South Cumberland Regional Land Trust, for keeping this botanical treasure thriving.