Trixis californica [American Threefold]

[Andrea B.]

Blum, A.G. (2013) Trixis californica Kellog (Asteraceae) American Threefold. Flowers photographed in visible and ultraviolet light. http://www.ultraviol...ican-threefold/

 

McDowell Sonoran Preserve, Scottsdale, Arizona, USA

http://mcdowellsonor...ress.com/about/

http://www.scottsdaleaz.gov/preserve

22 April 2013

Wildflower

 

Synonyms:

• Trixis
  
• Plumilla
  

Comment:

The genus Trixis (Greek for 3-fold) is widespread across the US desert Southwest and Mexico. The rayless flowerhead is deceptive because the lower lip of each disk flower is elongated and thus appears to be a 3-toothed corolla ray. In ultraviolet, the lower lip is UV-bright, but the coiled upper lip is darker.

 

Reference:

1. Morhardt, S. & E. (2004) Trixis, page 76. California Desert Flowers. The U. of Cal. Press, Berkeley, CA.

 

Equipment:

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

 

Visible Light [f/11 for 1/500” @ ISO 400 in Sunlight with Baader UVIR-Block Filter]

 

Ultraviolet Light [f/8 for 1/200” @ ISO 400 with SB-14 UV-modified Flash and Baader UV-Pass Filter]