The Saguaro!

While we're still enjoying ourselves in Illinois, loving the green of a late Spring, I've still got some catching up to do on "posts to be written"! Most overdue is one on the saguaro cactus, recently flowering in our neighbor Susan's yard...


First, for those non-Tucsonans out there, is pronunciation of saguaro. It is a native American word, so is pronounced differently than spelled. Try this - "sah-wah-roh", that should get you pretty close. Some alternate spellings even help out by using the sahuaro spelling, including some local businesses. But most everyone knows what you are talking about - the iconic cacti that is likely a close second to the Grand canyon in symbolizing the State of Arizona. While the plant is a hardy survivor of the harsh Arizona Summers, it is very sensitive to low temperatures and excessive rainfall. As a result, it is not found outside the borders of the state except perhaps Sonora, Mexico. So yes, all those old-timey western movies that were supposed to have taken place in Texas showing saguaros were all filmed in Arizona, as they will not survive outside the state!





It has been over a month already (time flies!) that I posted this year's first pictures of Susan's saguaro. I wrote an iconic post about it 2 years ago, but have more to add this time around... Note that mostly saguaro blossoms (the Arizona State Flower!) bloom at the top of the main trunk and arms, so usually they are located 20 to 50 feet off the ground (note another pair of Susan's plants at upper left). But fortunately, one of Susan's saguaros suffered some frost damage a few years back, one of the arms drooping to head level, this year making the flowers easily accessible. I already posted some anaglyph images of the new buds in the first post above. The lower branch started blooming in early May, the buds popping open just after sunset and lasting into the morning of the next day. Of course, I was there to document it - these anaglyph (3D) images taken on 9 May - the same morning as the Mercury transit across the sun! Of course, you need the red-blue glasses to view them, red filter on the left...

I also took a number of focus-stacked images as with the close-up macro work, it is difficult to get good depth of focus. Here, several or many images are combined with slightly different focal positions and combined in Photoshop to extend the depth of focus much deeper than normally possible. At left is a 9-frame stack that shows the entire flower. In another setup, an ultra-closeup of the saguaro blossom was framed and 13 images combined for maximum depth of field. In that one, I cropped it down to the full camera resolution to retain full sharpness of the flower. Shown at right, you can see the flower anthers loaded down with pollen grains...


Finally, I took some images for making time-lapse sequences of the flowers opening at night. I was fooled several times, checking the buds at sunset and swearing that none of them were going to open that evening, only to check an hour later and finding them well on their way to open! Finally I set up on some of the buds that were likely candidates and had my fingers crossed they would bloom and I got a couple over several nights that way. I'm also looking out for pollinators, but only found small insects on these flowers. I've heard stories of bats pollinating these at night, but never captured any...





This is likely the last of the saguaro posts of the season as by the time we return to Tucson, I'd not expect much activity. But there will certainly be other topics on which to post!