Stealing Sugar and Killing for Nitrogen

Common butterwort – Pinguicula vulgaris by Björn S..., 2015, Flickr (https://www.flickr.com/ photos/40948266@N04/18350804581/ in/photostream). CC BY-SA 2.0.

By Dr. Ken Marr

Curator of Botany

Illustration of a butterwort plant.

British Columbia’s Outlaw Plants

Sugar is life! Photosynthesis, arguably the most important chemical reaction on Earth, uses the sun’s energy to combine carbon dioxide and water to form sugar and oxygen. Sugar is the energy currency of ecosystems. Complex assemblages of primary producers (plants, algae and some bacteria—the only organisms in which photosynthesis occurs), herbivores and carnivores (animals), and decomposers (fungi and bacteria) depend directly on the metabolism of sugar.

Nitrogen is equally important to life. Soil bacteria convert nitrogen gas into a form that can be absorbed by plant roots. Nitrogen atoms are present in every amino acid— the molecules that form protein—and in DNA, the genetic code of life. Alkaloids, molecules that include a nitrogen atom within a ring of carbon atoms, do a great deal for us: they keep us alert (caffeine) and treat our pain (morphine). Often bitter-tasting, alkaloids also deter insects from feeding upon plants. (continues next page)

(right) Witches’ broom (a dense cluster of branches near the top of the tree) formed by abnormal branching of the tree caused by mistletoe.

(below) Mistletoe growing on lodgepole pine near Manning Provincial Park.

(bottom) Dodder growing on sea asparagus near Crofton. A single branching orange stem can be greater than 700 m long! Photograph courtesy of Greg Suftin.

Remarkable adaptations allow some BC plants to secure their nutrition from other plants and even from animals. One of the rarest is a pitcher plant that occurs in the Peace District, though it’s more common farther east. There are also sticky-leaved sundews, which grow in many bogs. Insects that fall into the liquid of the slippery “pitcher” of the pitcher plant or are trapped by the sticky leaves of the sundews provide these species with sugar and nitrogen. Butterworts likewise have sticky, insect-trapping leaves, with enzymes that digest insects, releasing their nitrogen-containing compounds to be absorbed by the plant.

Many conifers in British Columbia are infected by mistletoes. Their explosive fruits spread the seeds from one tree to another. These non-photosynthetic plants sprout rootlike structures that penetrate into the conductive cells of the host tree to secure sugar and other nutrients. Infected branches grow in an abnormal manner, forming a dense mass of branches referred to as a “witches’ broom.” Another unusual plant, the orange-stemmed dodder, grows in dense patches, with narrow stems up to hundreds of metres long that coil around the stems of specific host species.

As you enjoy British Columbia’s spectacular wild places, keep an eye out for some of these fascinating outlaw plants. Look for witches’ brooms in forests, dodder on beach plants and butterworts on mossy seeps. You never know what you’ll find!

Some of Laing’s work published between 1924 to 1935.

The Records of Hamilton Mack Laing at the BC Archives

By Sue Halwa

Archivist