It's That Time of Year!

A couple notable milestones today - first of all, it broke 100F in Tucson today!  Turns out, 16 May is about average for it to happen.  Last year, it didn't happen till 1 June, but then set a record by exceeding 100F for every day of the month, the first time it has ever happened!  It has also broken 100F as early as April too, so really, it is the season for that to happen.  One of the local stations runs a contest to name the date, hour and minute that it happens, the big prize being a trip to Cancun or somewhere, so is kind of a big deal 'round here.  They call it the "Icebreak Contest", when the proverbial ice breaks on the Santa Cruz River...  Of course, the Santa Cruz is a dry wash for 360 days of the year, so you have to use your imagination!

The other milestone is that our neighbor's saguaro cactus started blooming yesterday!  A couple years back it was damaged by some cold temperatures (they don't do well below 28F for more than a few hours).  It lost a good 60" (1.5 meters) off the main trunk, and one of the arms, normally held high, droops down to almost head level.  The good thing about that, if it survives, is that the flowers normally out of reach will be easily accessible.  The amazing thing about this particular branch is that it had literally dozens of buds on it.  Unfortunately they don't bloom all at once, only a couple per night typically, but it may keep me entertained for weeks!  The shots shown at left and right were taken a couple days ago, and you can see my reason for excitement.

What you may not know about the Sonoran Desert icon, Cereus giganteus or Carnegiea gigantean is that they are night bloomers, opening shortly after sunset and close up in the heat of the next day.  They require pollination from other plants, but fortunately there are numerous night-time and early-morning pollinators from long-nose bats, birds and insects.  One of my favorite local bloggers, biologist M. Brummermann has a great post on non-insect pollinators...  Shown at left is tonight's crop of flowers, freshly opened! 

I checked on these about an hour after sunset and they were just starting to open.  An hour later and they were in full bloom!  The closer you look, the more the flowers look fake!  The short white petals look like the satin cloth that make up a lot of artificial flowers, and the cup-shaped bowl full of pollen almost looks artificial in it's perfection.  I'm going to look at these in the morning to see if they look a little more ragged after a night's worth of visits...  At least I'm glad I don't have to be 20 feet in the air in the dark to take these closeups!


Edit:

Of course, there are a couple things I forget when writing a post...  Concerning the 100 degree temps, of course, the local qualifier is that at least "It's a dry heat!"  It is not as uncomfortable as you might think because your body's cooling system works fine - while you sweat, you sweat efficiently - no sweaty clothes!  And that is one of the reasons we can have low temperatures near 60F, yet break 100F later in the day - dry air takes less energy to heat up than humid, so you can usually infer that when it is that hot, it is also dry.  Case in point, last night when we heard it had broken 100F on the 5pm news, the dewpoint at the time was 1F, for a depression of nearly 100 degrees (!) making the humidity 3%!

Shown here is a photo of the neighbor's saguaro flower this morning after surviving the night time pollinators.  Looks none the worse for wear, though perhaps in our part of town we don't get many pollinators.  There are some differences from the freshly-bloomed blossom above - the center of the flower is much deeper, either an artifact of the flower further blooming or of pollinators burrowing in to get to the nectar at the flower bottom, their ultimate interest in exchange for carrying pollen...

So of course, I had to stick my finger in it...  If you went to the Brummermann blog above, you saw birds that stuck their heads into the flower and came out yellow-headed!  So yes, I had to try and sure enough, the pollen coats your finger, or whatever it comes in contact with to carry to the next plant and cross-pollination goes on.  The macro lens (Canon 100mm used for all these shots) can resolve the pollen grains against my fingerprint structure...

I'm sure that by the time this saguaro is done blooming, you'll be bored with all my posts on it.  Then, of course, comes the fruit and seeds from the plant - much more interesting when the flowers/fruits/seeds are at eye level than 30 feet in the air!