Ferocactus wislizeni [Compass Barrel]

[Andrea B.]

Blum, A.G. (2018) Ferocactus wislizeni (Engelmann) Britton & Rose (Cactaceae) Compass Barrel. Flowers photographed in ultraviolet and visible light. http://www.ultraviol...compass-barrel/

 

Desert Botanical Garden, Phoenix, Arizona, USA

25 Apr 2013

Wildflower in botanical garden

 

Synonyms:

• Echinocactus wislizeni Engelmann
  
• Echinocactus emoryi Engelmann 1848
  

Other Common Names:

• Arizona Barrel Cactus
  
• Candy Barrel Cactus
  
• Fishhook Barrel Cactus
  
• Biznaga de Agua (Sp. Water Barrel)
  

Comment:

This barrel cactus eventually uproots itself from its increasing southward lean as it ages. These are youngsters, maybe 12-15 years old, not leaning much yet.

Note the UV-dark top center area in the blooming barrels. Some of the topmost fishhook spines are also UV-dark while the others (older, perhaps?) are UV-bright. The flower is UV-dark with strong iridescence as is often seen in other cactus blooms. The anthers are notably lighter in UV but not quite UV-bright.

 

Reference:

1. Flora of North America Online (03 May 2018) Ferocactus wislizeni (Engelmann) Britton & Rose, vol. 4, pp. 244. FNA, New York & Oxford. http://www.efloras.o...on_id=242415343

 

Equipment [Nikon D600-broadband + Nikon 105mm f/4.5 UV-Nikkor]

^{Unless otherwise noted.}

 

Visible Light [f/22 for 1/200" @ ISO-400 in Sunlight with Baader UVIR-Block Filter]

The cactus on the left is blooming. The one in the back shows the developing fruits.

 

Ultraviolet Light [f/22 for 1.3" @ ISO-400 in Sunlight with BaaderU UV-Pass Filter]

^{f/22 !!! For a little over a second !! Gotta love that UV-Nikkor ...and I do. "-)}

Note, please, the dark top of the blooming cactus on the left. That does not appear on the rightmost cactus.

 

Visible Light [f/7.1 for 1/1000" @ ISO-200 in Sunlight with Nikon Coolpix A]

The cactus wears a crown of flowers and buds during blooming season.

 

Visible Light [f/11 for 1/1000" @ ISO-400 in Sunlight with Baader UVIR-Block Filter]

Note the beetle in the anthers. The cactus flowers of all types were full of bugs, beetles, flies and bees down at the base of the flower hiding in the anther forest.

 

Ultraviolet Light [f/11 for 1/100" @ ISO-400 with SB-14 UV-modified Flash and BaaderU UV-Pass Filter]

There's a big striped insect in the anthers, probably a bee? Lithurgus bees are the chief pollinators of Ferocacti.