Machaeranthera asteroides [Fall Tansyaster]

[Andrea B.]

Blum, A.G. (2018) Machaeranthera asteroides (Torrey) Greene (Asteraceae) Fall Tansyaster. Flowers photographed in ultraviolet and visible light. http://www.ultraviol...all-tansyaster/

 

Boyce Thompson Arboretum, Superior, Arizona, USA

24 Apr 2013

Wildflower in botanical park

 

Synonym:

• Dieteria asteroides Torrey
  

Comment:

This southwestern US native has a rather scrubby appearance as a plant. But when the blooms break out in bright purple, it makes for quite a striking sight. In UV the UV-bright center is surrounded by a small UV-dark ring in reversal to its Visible brightness. The rays are moderately UV-reflective with darker veining.

 

Reference:

1. Flora of North America Online (03 May 2018) Dieteria asteroides Torrey, vol. 20, p. 396. FNA, New York & Oxford. http://www.efloras.o...on_id=250066479

 

 

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

Unless otherwise noted.

 

 

Visible Light [f/11 for 1/200" @ ISO-200 with Onboard Flash and Baader UVIR-Block Filter]

 

Ultraviolet Light [f/11 for 1/125" @ ISO-400 with SB-14 UV-modified Flash and BaaderU UV-Pass Filter]

 

Visible Light [f/6.3 for 1/640" @ ISO-100 with CoolpixA in Sunlight]

Many desert plants besides cactus have some spines.

 

Visible Light [f/6.3 for 1/640" @ ISO-100 with CoolpixA in Sunlight]

The leaves, stems and involucre are all quite hairy.