Tracing The Visible and Invisible Work of Roots

Such enormous quantities of water are involved, a single wheat plant needs 4 pints each day to survive, while a mature oak tree may consume more than 200 gallons that many plants ceaselessly extended their roots in the desperate search for moisture.

The roots of some plants grow at a prodigious rate.  In one study, scientists found that a four-month old rye plant had put out a total of 385 miles of roots, on average of 3 miles every day.  If the root hairs which help the route to grip the soil as well as to take in water had been lead out in two and they would have stretched for 6600 miles.

Keeping a grip

Besides being the plans vital link with water, roots also anchor it to the soil.  Where the soil is then, very large plans may need more support than under ground roots can provide.  Many tropical trees for example have such dense heavy foliage that they produce wide spreading buttress roots that grow out from the trunk to hold it upright.

In wet soils and habitats subject to flooding, some trees grow supports known as stilt roots.  In the pandanus or screw pine a number of 10 branch like roots grow down at an angle from the trunk forming a structure that looks like an untidy wigwam.  These roots provide such effective for support that sometimes the base of the original trunk will wither away completely.

The Banyan tree of tropical Asia grows so many supporting roots that it looks more like a dense thicket than a single plant.  As the Banyan’s branches spread outword, fine vertical roots grow from them down to the ground. 

Once they take root in the soil, they thicken up to form a cluster of pillars supporting the trees massive canopy.  In time, the pillars themselves produce branches, which in turn drop roots to the ground in this way the Banyan is able to spread to enormous size one near Poona in India has 320 pillars.  It measures of astounding 2000 feet in circumference, and it is said that its crown could shelter some 20,000 people.

Image via Wikipedia

Did you know?

The African baobab tree may have a circumference as great as 100 feet.  One in eastern Zimbabwe is so wide that it’s hollowed out trunk has been used as a bus shelter, holding as many as 40 people.