Читать книгу Intelligence in Plants and Animals онлайн

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No better example of carnivorous plants could be taken than Dionæa muscipula, or to use the common name, Venus’s Fly-trap. It is a species that is indigenous to North Carolina and the adjacent parts of South Carolina, affecting sandy bogs in the pine forests from April to June, and a representative of the Droscraceæ, or Sundew Family. One cannot fail after once seeing it of becoming impressed with its peculiar characteristics. It is a smooth perennial herb with tufted radical leaves on broadly-winged, spatulate stems, the limb orbicular, notched at both ends, and fringed on the margins with strong bristles. From the centre of the rosette of leaves proceeds at the proper time a scape or leafless stalk which terminates in an umbel-like cyme of from eight to ten white bracted flowers, each flower being one inch in diameter. The roots are small and consist of two branches each an inch in length springing from a bulbous enlargement. Like an epiphytic orchid, these plants can be grown in well-drained damp moss without any soil, thus showing that the roots probably serve for the absorption of water solely. Three minute pointed processes or filaments, placed triangularly, project from the upper surface of each lobe of the bi-lobed leaf, although cases are observed where four and even ten filaments are found. These filaments are remarkable for their extreme sensitiveness to touch, as shown not only by their own movement, but by that of the lobes also. Sharp, rigid projections, diminutive spikes as it were, stand out from the leaf-margins, each of which being entered by a bundle of spiral vessels. They are so arranged that when the lobes close they interlock like the teeth of an old-fashioned rat-trap. That considerable strength may be had, the mid-rib of the leaf, on the lower side, is quite largely developed.

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