Phycology


Richard McCourt examines a specimen of Chara vulgaris
from Sulfur Spring, near Great Falls, Montana.

Dr. McCourt is Associate Curator of Botany at the Academy of Natural Sciences
in Philadelphia, Pennsylvania. Phycology is his principal field of interest.
1

The smell of the spring that caught Lewis's attention comes from hydrogen sulfide created by decaying anaerobic bacteria at the bottom of the pond.2 But there is another odor in the neighborhood—at least distinctive, some say obnoxious, and decidedly unappetizing—that is peculiar to a species of algae growing there today, called Chara vulgaris Linneaus.3 For instance, charaphytes have large cells that are studied by biologists interested in how cells maintain their interior water pressure. It is one of the most widespread members of the genus, which accounts for the name of the species, vulgaris, meaning "common."4

In 1813 the Reverend Henry Muhlenberg (1753-1815), a German-American botanist and Lutheran pastor, published his Catalogus plantarum Americae septentrionalis (Catalogue of North American Plants) in Lancaster, Pennsylvania (second ed., 1818). It contained over 700 species of algae, lichens, fungi and mosses that he had collected within a three-mile radius of his parish in Lancaster.

It thrives in water hardened, as this is, by flowing through limestone. Dr. McCourt's colleague, Ken Karol, positively identified the specimen pictured at left, by sequencing a gene in its chloroplast. A chloroplast is the structure of genes within a cell where photosynthesis occurs. Gene sequencing is a method of studying molecular structure of a gene by determining the arrangement, or sequence, of its components.

The tops of Chara vulgaris Linneaus such as Dr. McCourt is holding in the other two photos on this page create a glistening, slimy surface on the water at the edge of Sulfur Spring, among grasses and other riparian plants. (The penny is just for scale.)

Scratch-and-sniff

H ere at Sulfur Springs today, it is easy to overlook—"over-smell"?—the intrinsic beauty of a charaphyte. In this setting, remote from the modern urban monotony of gasoline or diesel fumes and the fat smell of hot grease, which suffuse our otherwise sanitized and deodorized days, the odor of Chara vulgaris is unique, and is so conspicuous that one may wonder why none of the journalists mentioned it. They might simply have ignored it, of course, given the variety and richness of the olfactory environments they passed through day by day. Besides, it couldn't have been as much of a turnoff as the stink of decaying bison carcasses they had to wade around in the Missouri River below the Falls.

Perhaps it's just as well we don't have scratch-and-sniff utilities on the World-Wide Web—yet.

  • 1. The study of algae is called phycology, from phykos, the Greek word for seaweed.
  • 2. Some say hydrogen sulfide smells like rotten eggs, implying that rotten eggs smell like hydrogen sulfide. But anyone who has raised chickens the "natural way," and has had to locate a long-lost egg among the beds of henhouse straw, is entitled to question that. And anyone who has scrambled a too-well-hidden Easter egg with a weed-eater in mid-August definitely will not think of hydrogen sulfide, but of the quickest path to a shovel with a—as Clark would have spelled it—verry long handle.
  • 3. In Lewis's day the term alga (plural, algae) was not yet in any dictionary, for seaweed and similar "marine productions," as Lewis called them, were still considered to be related to terrestrial plants. In the 1830s, however, scientists began to discover that marine algae lack functional roots, stems, leaves, and plant-like reproductive systems, but instead represent a unique and extremely complex group of photosynthetic organisms. It remained for later investigators to grasp the far-reaching ecological significance of the biotic kingdom that was given the name Protista in 1866, but which attracted relatively little attention until a century later. Phycology, as the study of algae is called, remains one of the most challenging frontiers of the scientific community. For an account of a recent discovery by Dr. McCourt relating to a certain species of algae in the evolution of plant life on earth, see the News Department of the Biodiversity Research Group at the Academy of Natural Sciences, http://www.acnatsci.org/press/plantevolution.html/
  • 4. More information about the fascinating world of Charophyta may be read on the Web site for the Algal Collection of the U.S. National Herbarium, of the Smithsonian Institution, http://www.nmnh.si.edu/botany/projects/algae/Algd-Cha.htm#charo/ and also at http://www.life.umd.edu/labs/delwiche/Charophyte.html/