Tussock, Vernal Pool: Origins, Forms, Histories of Words Meaning Marsh, Swamp

The natural features of a region are its topography (Greek topos, "place"). Marshes, swamps, and related areas are important kinds of topographic features.

In the current alphabetic series of terms that refer to such places, here are the origins, forms, and histories of tussock and vernal pool. The dates of forms and meanings come from the Oxford English Dictionary and Merriam-Webster's Collegiate Dictionary.

Tussock
Modern English tussock (18th century) comes from the earlier form tussocke (16th century), of unknown origin.

The original meaning of tussock is a tuft or bunch of hair (16th century).

A compact tuft or matted clump of grass or sedge is also a tussock (16th century). By extension, the word refers to an area of raised solid ground in a marsh or bog that is bound together by roots of low vegetation, such as grasses and sedges.

Tussock grass is any of various grasses or sedges that typically grow in tussocks. Many such sedges form dense tufts in bogs or wet meadows, especially tussock sedge, a common North American wetlands sedge (Curex stricta).

Vernal Pool
Vernal, meaning "occurring in the spring," entered English in the 16th century from Latin vernalis, an alteration of vernus, from ver ("spring").

The word has long been used to describe anything associated with springtime, such as vernal equinox (the time when the sun crosses the equator in the spring), vernal flower, vernal bird, vernal shower, and vernal flood.

The term vernal pool is used primarily in the United States, originally to denote any of the small periodically filled depressed wetlands in western regions. Such pools collect water during winter and spring rains, maintaining a shallow covering of water for varying lengths of time. Sometimes they fill and dry several times during a single season. However, they are often completely dry for most of the summer and fall.

Vernal pools, usually located on gently sloping grassland plains, range in size from small puddles to little lakes. Bedrock or a layer of hard clay under the depressions helps maintain the water in the pools.

Vernal pools attract animals and vegetation. Many birds, such as ducks and egrets, use the pools as a seasonal source of food and water.

As spring turns to summer and the water level goes down, wildflowers often bloom along the receding shoreline. By early summer, evaporation has taken all the water, and the vernal depressions become brown and cracked.

However, they still provide a habitat for many plants and animals, some of which spend the dry season at the depressions as seeds or eggs and then grow and reproduce when the water returns in the spring.

From its original application to western seasonal wetlands, vernal pool has been extended to include small ephemeral wetlands in other parts of the country. These generally differ from the western pools by often lacking vegetation and being associated mainly with amphibians, such as salamanders.
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Encyclopaedia Britannica Ready Reference 2004. CD-ROM. Encyclopaedia Britannica, 2004.

Merriam-Webster's Collegiate Dictionary. 11th ed. Springfield, Mass.: Merriam-Webster, 2006.

Merriam-Webster's Geographical Dictionary. 3rd ed. Springfield, Mass.: Merriam-Webster, 2007.

The Oxford English Dictionary. 2nd ed. Oxford, England: Clarendon Press, 1989.