Botany Photo of the Day
In science, beauty. In beauty, science. Daily.

February 16, 2016: Botany Photo of the Day will return this spring with a new format similar to the new UBC Botanical Garden web site. In the meantime, please enjoy the restored content!

Peniocereus greggii

Peniocereus greggii

Today's contribution is from Flower of the Desert@Flickr of (if I'm correct) Arizona, USA (original image via BPotD Flickr Group Pool). Many thanks!

The flowers of Arizona queen of the night (aka night blooming cereus) last one night before fading away. Perhaps more amazing, the individuals within a population of plants bloom synchronously on less than 5 nights per year and the flowers are self-incompatible. How, then, do the plants get pollinated given the narrow window of time? A few scenarios are possible. Perhaps a generalist pollinator species could visit the flowers, but presumably a generalist would have a lot to choose from and it would be quite hit-and-miss that they'd visit these flowers often enough (and I suspect most generalists are not active at night). Perhaps a specialist insectoid pollinator species emerges at the same time as Peniocereus blooms. That hasn't been shown to be the case.

The question of the floral biology of Peniocereus greggii was examined by Dr. Robert Raguso and a team of researchers (see Raguso, RA et al.. 2003. Trumpet Flowers of the Sonoran Desert: Floral Biology of Peniocereus Cacti and Sacred Datura. International Journal of Plant Sciences. 164:877-892). The researchers discovered that Peniocereus greggii and the often-growing-nearby and spring-to-fall blooming Datura wrightii (see a related species) shared a few things in common, including pollinators (hawk moths at dusk, bees in the morning), pollination reward, (lack of) UV reflectance and a few benzenoid compounds (components of floral scent). In other words, the pollination of Peniocereus greggii seems to rely on the presence of Datura wrightii to sustain a population of shared hawk moth pollinators that is both specialist enough and in sufficient numbers to visit its flowers when it is in bloom (as for the bees, recall the suggestion that generalists visit many plants and the chances of cross-pollination are reduced).

Read a factsheet about Peniocereus greggii via New Mexico Rare Plants. Two other photographs are available to be viewed via Wildflowers of Tucson, Arizona. Lastly, a legendary tale and a curatorial anecdote offer two different perspectives on the plant via the site of Tohono Chul Park.


Ah, what a treasure I've got to pass on! The link below connects to an etext of Dorothy Canfield Fisher's "The Brimming Cup". Fisher was an iconic Vermont author active in the first half of the 20th century. The book is set in the hill country Vermont of that time, when the state was still decidely agricultural and low-tech. Scroll down to:
The 'Cereus' part of it is in the middle of the chapter, but I recommend starting from the beginning. This story is a Vermont classic. Enjoy!

How timely! I was given one of these as a greenhouse plant here in the eastern U.S. and have been puzzling over what to do with it. Looks like the flower is worth waiting for!

Thanks for the stories and for the information on pollinators. I am always curious about the pollinators.

Tohono Chul Park here in Tucson has an annual Queen of the Night celebration on the night that these plants bloom, usually in June sometime. It's different every year, so you have to be on their special email list to find out. It's a very mystical experience, or it would be, if there were not so many people crowding the trails!

I have had enough of the botany for awhile, please cancel my subscription to it .

Jessie Chayer.

Jessie, there is a cancel your subscription link at the bottom of every email.

I'm researching for this plant coz i believe this is the plant i've been looking for. We have this plant for the past 40yrs or so. Last July 28, it bloomed and had 8 flowers. It also bloomed last year around june or july but it only had 2 flowers. What intrigues us is that last july 27, 2006 my mom died and this yr we celebrated her 1st death anniversary. According to my father, the chinese name of this plant is the same with my mom. What a coincidence?!

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