Wednesday, May 13, 2009

Cereus Giganteus

Since we are on the topic of native desert plants, time to address the Saguaro (sah-whar-oh) cactus. My eyes are usually a little bleary on the way to work, but am always on the lookout for cactus flowers on the way home in the afternoon. Saguaro flowers are rare on that schedule - they are night bloomers and are usually closed back up by noon.

There is a good sized cactus in front of neighbor Susan's house - likely a transplant as it is about 8 meters (over 25 feet) tall, and would be close to 100 years old at that height in the wild. These houses were built about 40 years ago, and in my 20 years here, it has always been over 5 meters (15 feet) tall. The first photo at left was taken yesterday afternoon from ground level. Lots of flower buds, but no blossoms 2 hours before sunset. The next photo was taken this morning, 2 hours after sunrise - lots of flowers with bees and insects too!

Despite the abundance of insects, the most important pollinators of saguaros (Cereus Giganteus or Carnegiea Gigantea) are bats. I was amazed a decade or more ago when one of our amateur astronomers brought in a night-time video of bats feeding on pollen and nectar from the flowers. They did this while flying past the open flowers, using their long tongues to reach far inside the flower! The closeup image here doesn't do it justice - realize I was shooting blind, with the camera atop a nearly 1.8 meter monopod held over my head using the autofocus and the self-timer, hoping to get a flower or two in the shot before I had to leave for work. There are future yet-to-blossom buds, as well as the wilted results of past blooms. An unusual-looking flower (no doubt adapted for it's unique method of pollination), it is the state flower of Arizona. If the flower was pollinated, a fruit will develop and ripen. Each fruit might contain thousands of seeds, and is heavily sought after by animals, as well at local Native Americans as an important food source. Hmmm, sounds like a July post...

1 comment:

Anonymous said...

Nice shot considering the difficulty.

Cereus(ly) ahem... I mean Seriously, the saguaro is among the various plant or animal species named for a person rather than for group characteristics. Fortunately, in recent years, the night bloomer has regained, more often, the "Cereus" (serious) classification.

Andrew Carnegie, a "giant" of a philanthropist financed quite a number of scientific endeavors. (wow that's a huge understatement) Carnegie's financing of research related to how cacti survive in arid conditions, eventually leads to the mighty saguaro being named after him. (So also, is the Diplodocus carnegii, a dinosaur) not sure i spelled that quite right...

see also:

"1902 With the blessing of President Theodore Roosevelt, Andrew Carnegie founds and endows The Carnegie Institution to conduct scientific investigations. Coville, now the Botanist of the US Dept. of Agriculture, appeals to the Institution to set up a botanical laboratory in the desert. Purpose: to discover how plants do manage to survive and thrive in hot, dry environments. The Carnegie sets aside $8000 for the lab and delegates Coville and Daniel T. MacDougal to find a suitable place for it.

1903 After an overland journey that takes them to promising sites in California, New Mexico, Chihuahua and Sonora, as well as Arizona, Coville & MacDougal choose Tumamoc Hill and its surroundings."


It is told that Carnegie visited the lab on the hill once, and was taken in by the enormity of the mighty saguaro.

again... nice photos