Larry Byersp age 10.. of Toronto. Canada..
How can a cactus go so long without water?
Cactus plants grow in dry desert country. Sometimes it is years between showers. Yet a certain big cactus may grow 50 feet tall. This is the saguaro cactus. It stands like a giant candlestick in the dry lands of Mexico and the southwestern United States.
Altogether there are same 1500 different kinds of cactus w big and small. All manage to survive on a very small amount of rainfall. And in certain seasons. they even manage to adorn themselves with gorgeous blossoms.
The trick of course. is in storing water. All cactus plants know how to hoard the little rain that falls. A green oak tree loses gallons of water through its leaves. The moisture dries out into the air„ The cactus plants guard themselves against this kind of evaporation. All their exposed parts are covered with thick. tough coats. The air cannot get the moisture stored within.
Most cactus plants have no leaves at ally The parts that look like leaves are usually stems and branches They are fat and fleshy.. for inside is stored the precious water. It is stored in special large cells. Maybe up to 90 per cent of the total weight of a cactus is stored water. The big saguaro cactus may be storing 30 tons of water.
These desert dwellers also know how to gather up the rain fast when it falls. Most desert showers are short and sharp. A sudden downpour drenches the ground with running water. It does not star long. For it quickly seeps into the sandy soil. The cactus plants are all set to grab it before it runs away.
Most cactus plants spread their roots near the surface to catch the sudden downpours. The roots reach over a wide area but they do not go down deep. If they were moved to watery soil: most of these desert plants would choke up and perish.
Water is the most valuable substance in the desert.. And every cactus has a store has a store of it. Naturally. the thirsty desert animals would steal it if they could. but cactus plants know what to do about that. so they all wear barbs. spines or prickles. Any thirsty animal is going to get his nose poked before he can chew into‑the cactus and get at its supply of water.
These wonderful plants are native Americans. They are said to have started in Mexico and grown used to desert life. Gradually they spread north and south. Andy's favorite is the barrel cactus. It is a chubby plant. just like a green barrel with prickles and fancy grooves. It bursts into flower with a wreathe of orange‑colored blossoms around the top of its fat little heads The barrel can hold enough water to last through six years of drought.