Saguaro Cactus (Carnegiea gigantea)
Walking around the premisses will bring you sooner or later close up to one of
those gigantic cacti. I thought it would be a good idea to learn
some more about this plant.
Luckily there is a lot of information available on the internet.
Here are some:
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Sonora Desert, Quartzsite, AZ
Kofa Mountains in the background |
A cactus can be as much as 150 - 200 years old
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| Saguaro cactus, and I |
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some are partly damaged, but still alive.
The damage can happen through desert rats and kangaroo mice. They gnaw on the fleshy
cactus part. Those wounds subsequently can get infected by fungi. |
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There are many different forms of growth,
some Saguaro have multiple arms, others have none. |
The branches are called "armes". Certain growth spots develop either into flowers or arms.
Nobody knows exactly what decides whether it is is the one or the other.
Flowers develop always on the very top of the cactus or arm.
Around its centre the soft flesh contains a lot of water.
Those fleshy cells inside shrink with drought and enlarge when water is available.
A cactus can visibly swell up, after a good rainfall, similar to an accordion.
Here ,one can see the start of a new pleat. Those vertical pleats guide rainwater
right down to the root system. Pleats contain all those fleshy water conserving cells.
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Palo Verde trees are important nursing plants for a young cactus. They provide
valuable shelter against cold or heat, nutrient rich soil and access to water through
their deep root system. |
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| New grow points on a Saguaro Cactus |
Cactus spines (thorns) are actually transformed leafs.
They are thin to minimize surface evaporation. They are nearly
as strong as steal needles.
These are growth points that will turn into more arms.
A saguaro cactus can grow up to 40 - 60 feet (12 - 18 m) tall.
But they grow very slow, it takes 20 to 50 years to grow just 3'.3" (1m).
Saguaro roots small and very shallow and grow up to 100 feet ( 30 m diameter) around
the base of the cactus with one tap root that goes down about 2 feet ( 60 - 70 cm)
The wooden ribs in the centre of the cactus and are visible when the flesh is eat off, or the plant damaged otherwise.
The ribs support the growing plant and give it strength.
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| Dixie and Peter examine a dead, fallen over cactus |
One or the other cactus dies off. Old age, drought or damage to the root system
may be the reasons.
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| Saguaro dried up and fallen to the ground |
Those cavities that birds like woodpecker, wrens, finches and other nest in
are called "Saguaro boots".
Woodpeckers carve out those holes with their strong bills.
Then the cactus creates lignin rich callus tissue in order
to close the wound off against water loss.
The Native people used these hard shells as containers for water. |
| A Gila Woodpecker flew off of a Saguaro |
It was still too early for the Saguaro to have flowers, they will bloom the first two week in April, but I learned that important pollinators
are among others:
Bees, White-winged Doves, Hummingbirds and Bats.
The fruit are edible.
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| Source: USDA Forest Service |
I hope you enjoyed my short Saguaro cactus excursion.
Some of the info was from:
desertmuseum. org Saguaro - Cactus Facts
de.wikibrief. org, Saguaro
others were just googled
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