Native from North America, the Saguaro cactus can only be found
in the Sonoran Desert (US states of Arizona and California and Northwestern
Mexico). The peculiarity of such plant is part of the imaginary of the native
tribes since ancient times. Many legends have been build-up around the cactus;
many of those legends confer special gifts or divine powers to these plants. Its
shape and size (which can grow over 20 meters tall) makes a superb view along
the desert landscapes, and this was probably the reason why natives believe
that the Saguaro cacti were reincarnations of the spirits of Native American
warriors, standing in the desert as guardians of their people with arms upwards,
supplicating for water and light to the Creator.
Seri People in Sonora Desert, Mexico (Photo: Graciela Iturbide, 1979) |
As in a desert whatever you find is a gift from heavens, the
Saguaro has been venerated for generations and used as a source of food and
shelter for the natives, especially by the Tohono O’odham and the Mexican Seri
people, as well as for other inhabitants of the desert. The fruits are an
important food source not only for the people but also for birds, whereas the
plant itself is used by some species for nesting. The needles were used for
sewing, and other parts of the plant were used to build shelters or to produce
tools.
A - Parabuteo unicinctus (Photo: Walter Meayers Edwards); B - Micrathene whitneyi (Photo: Bruce D. Taubert); C - Zenaida asiatica; D - Bubo virginianus (Photo: Jim Zipp) |
But the real magic happens during the quiet night, when
pollination takes place. Any guess on who’s starring this time? Bats! Just take
a look at the flowers – white, open, big and on the top of that, it releases a sweet
smell of nectar during the night.
Bat pollination of Saguaro flowers by Leptonycteris yerbabuenae (Photos by: Merlin Tuttle / Bat Conservation International) |
However during the day the cacti flowers
keep opened, so other animals can pollinate when bats are asleep – after all,
nothing forbids them to do the job, even though the main pollinator is the
lesser long-nosed bat (Leptonycteris
yerbabuenae). Unfortunately these bats are threatened and considered Vulnerable according to IUCN, especially due to
habitat destruction.
Day pollinators |
We have to admit cacti flowers are absolutely gorgeous. More
than the natural gorgeousness, they are a botanically interesting case to
study. Caryophyllales’ members tend to be odd and have their own peculiarities,
and so does Cactaceae, having an immense (botanically speaking, we actually say
infinite) number of petaloid tepals.
No, not petals – they are not real
petals, Caryophyllales lack petals and this is probably one of the reasons why
so many different trends arose in this group. They had to find a way to attract
pollinators even though they did not have petals to do it! What a task… But
they went over it and they reinvented petals with the genetic sources they had.
Phenotypically, my dear Cactaceae, I must admit I love what you invented –
isn’t Nature truly an artist?
Photo source: Flickr (J Rindrr) |