Arnold (London, 1888); articles on Local Government in France in the Stock Exchange Official Intelligence Annuals (London, I908 and 1909); M.
Tropophytes.Plants which are hygrophytes during some favorl part of the year and xerophytes during the rest of the year; ~., deciduous trees and shrubs, deciduous herbaceous plants with iderground perennating organs, and annuals and ephemerals.
For example, deciduous trees shed their leaves in winter: geophytes go through a period of dormancy by means of bulbs, rhizomes, or other underground organs with buds; whilst annuals and ephemerals similarly protect themselves by means of the seed habit.
Under normal conditions in warm climates many of the species are perennials, but, in the United States for example, climatic conditions necessitate the plants being renewed annually, and even in the tropics it is often found advisable to treat them as annuals to ensure the production of cotton of the best quality, to facilitate cultural operations, and to keep insect and fungoid pests in check.
Flowering annuals are mainly aquatic. Water lilies, water hyacinths, which are an obstruction in many streams, and irises in rich variety give colour to the coast wastes and sombre bayous.
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