Science: Pitfalls and Lobster Pots

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Ghastly visions of plants that eat flesh have troubled the dreams of many imaginative men. In William Randolph Hearst's American Weekly a romancer named Dr. Carle Liche once described what he saw one frightful tree do to a native girl in Madagascar. ". . . Then while her awful screams . . . rose wildly . . . the great leaves slowly rose and stiffly . . . closed about the dead and hampered victim with the silent force of a hydraulic press. . . . The retracted leaves of the great tree kept their upright position during ten days, then when I came one morning they were prone again . . . and nothing [was left] but a white skull at the foot of the tree. . . ."*

The strict truth about carnivorous plants (The Carnivorous Plants; Chronica Botanica Co., Waltham, Mass; $6) is the business of McGill University's Emeritus Professor of Botany Francis Ernest Lloyd. After twelve years' work, field trips in South Africa, Australasia and North America, he has published the first comprehensive treatise on the subject since Charles Darwin's Insectivorous Plants (1875).

Carnivorous plants spread from South Carolina to Ceylon. There are about 450 species. Their methods of capturing their prey (ostensibly nothing larger than insects) are in some measure common to all. But Professor Lloyd breaks down their "trapping mechanisms" into six categories —pitfalls, lobster pots, snares, flypaper or birdlime traps, steel traps and mousetraps. The plants lure their victims by odors, the secretion of nectar and mucilage, the display of bright colors. With few exceptions, the plants have means of digesting their prey.* Enzymes and acids are excreted, and when these are accumulated together with the prey, something like an animal stomach results.

Among the most elaborate trapping mechanisms is that of the Dionaea (Venus's-flytrap). Indigenous to North and South Carolina, the Dionaea is a rosette of leaves, three to six inches across, rising from a rootstock more or less horizontally. The upper part of the leaf consists of two dished lobes whose outer margins have a row of coarse teeth. The plant appears to have been discovered by Colonial Governor Arthur Dobbs of North Carolina (1754-65).

Writes Professor Lloyd: "The body may be more or less compressed between the lobes. The glands [with which the surface of the leaf lobes are covered] then secrete a digestive fluid and in a few days the insect body disintegrates and the products are absorbed. In the course of ten days the lobes open again, and are ready to catch other prey. This may be repeated two or three times before the leaf reaches its complete maturity, when it dies."

The trap of Darlingtonia californica (also native to Oregon) is a typical "pitfall" among leaves that resembles a hooded cobra. The plant thrives on insects and might also get along on sausages —if they were properly prepared, †