Weird, peculiar, wonderful, strange, bizarre fascinating, and of course, unique, are the kind of word that are used to described the welwitschia. It is one of the few things on Earth that can truly claim to be one of a kind. There really is nothing like it.
An adult welwitschia consists of two leaves, a seem case and roots.That is all! Its two permanent leaves are unique in the plant kingdom. They are the original leaves from when the plant was a seedling, and they just continue to grow and are never she. They are leathery, broad, trap-shaped and they lie on the ground becoming born to ribbons and tattered with age. The seem is low, woody, followed-out, obconical in shape and study. It grows to about 500 mm in height. The largest recorded specimen is in the Messum Mountains and is 1.8 m high, and another on the Welwitschia Flat near the Swakop River is 1.2 m tall and 8.7 m wide. Carbon eating tells us that on averaged, welwitschias are 500-600 years old, although some of the larger specimens are thought to be 2000 years old. Their estimated lifespan is 400 to 1500 years. Growtg occurs annually during the summer months.
The seeds are 36 x 25 mm and have a large paper wing and are dispersed by wind, in spring, when the female one disintegrates. In their natural habitats, many seeds are lost to fungal infections and to small desert animals that feed on them. The seeds remain visble for a number of years. They germinate only if fairly heavy rain is spread over a period of several days. As these conditions rarely occur, it often happens that many plants in some colonies are the same age, as they all germinated in the same good year. The seedlings, once established, depend on the for for survival until the next rain occur.
There are more remarkable features that make welwitschia so difficult to categories. Unlike any other plant, the apical growtg point of the seem stops growing from an early stages. This caused the seem to grow upwards and outwards, away from the original apex (which remains dead), resulting in the characteristic obconical shape. In order specimens, continued growtg results in the undulating of the seem margin. This growtg habit is unique. Like other one-bearing plants (gymnosperms e.g. pine and cycads) it is a dioecious (male and female separate) one-bearer with named seeds, but the male flowers or microstroboli are reminiscent of the flowering plants (angiosperms). The water-conducting issue (xylem) is also typical of the angiosperms.
What is the main idea of paragraph four?
Welwitschia has remarkable features.
Welwitschia male fiowers are angiosperms.
Welwitschia stem grows away from the original apex.
Welwitschia apical growth stops from an early stage
Welwitschia xylems are reminiscent of angiosperms
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