Wednesday, 29 August 2018
Galapagos Day 5
First, some landscapes from the Cerro Dragon area of Santa Cruz.
A study of Prickly Pear Cacti (Opuntia)
The prickly pear cacti in the Galapagos presumably developed their tree-like forms as a defense against giant tortoises and land iguanas. By the way, the pads are part of the stem, while the spines are the leaves.
Galapagos Day 5
First, some landscapes from the Cerro Dragon area of Santa Cruz.
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| A sunrise view of Cerro Dragon from the ship. |
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| Low tide ashore. |
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| Dry shrubs against low lava hills. |
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| Two off-shore islets. |
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| Bitterbush in bloom. |
The prickly pear cacti in the Galapagos presumably developed their tree-like forms as a defense against giant tortoises and land iguanas. By the way, the pads are part of the stem, while the spines are the leaves.
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| A young prickly pear entirely covered in spines as a defense against predation by tortoises and iguanas. |
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| As the cactus grows, the main stem stays very spiny. |
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| A closer view of the downward-pointed spines -- they almost look like fur. |
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| Eventually, the main stem becomes tough enough that spines are no longer needed. But these low-hanging pads will be eaten by iguanas and tortoises. |
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| Eventually, the cactus resembles a tree. |
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| A fallen prickly pear shows that the stem is not woody, but a network of fibers. |
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| A closer look at a dead prickly pear stem. |
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| When prickly pear fruits fall off the cactus, they are choice food for iguanas and tortoises. |
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