Thymophylla pentachaeta var. belenidium [Fiveneedle Pricklyleaf]

[Andrea B.]

Blum, A.G. (2017) Thymophylla pentachaeta (de Candolle) Small var. belenidium (de Candolle) (Asteraceae) Common Dogweed. Flowers photographed in visible and ultraviolet light. https://www.ultravioletphotography.com/content/index.php/topic/2113-thymophylla-pentachaeta-var-belenidium-fiveneedle-pricklyleaf/

 

Tucson, Arizona, USA

Found in graveled border of parking lot.

11 March 2012

Wildflower

 

Synonyms:

• Five-needled Thymophylla
  
• Five-needle Fetid Marigold
  
• Common Dogweed
  
• Dyssodia belenidium (de Candolle) Macloskie
  
• Dyssodia pentachaeta (DC.) B.L. Rob. var. belenidium (DC.) Strotherv
  
• Dyssodia thurberi (A. Gray) B. L. Robinson
  

Comment:

The ciliate phyllary margins easily indicate the variety of this T. pentachaeta. Those little hairs also appear UV-bright in ultraviolet light in contrast to the very dark UV-absorbing appearance of the disk florets and rays.

 

Reference:

1. Epple, A.O. (1995) Five-needle Fetid Marigold, page 269. A Field Guide to the Plants of Arizona. Falcon Guides, Globe Pequot Press, Guilford, CT.

2. Flora of North America Online (2017) Thymophylla pentachaeta var. belenidium, Vol. 21, Page 242. FNA, New York & Oxford. http://www.efloras.o...on_id=250007191

3. USDA Natural Resources Conservation Service (2017) Thymophylla pentachaeta var. belenidium Plant Profile. US Department of Agriculture. https://plants.usda....le?symbol=THPEB

 

Equipment [Nikon D600-broadband + Carl Zeiss 60mm f/4.0 UV-Planar]

^{Unless otherwise noted.}

 

 

Visible Light [f/8 for 1/1250" @ ISO-400 with Nikon D3S + Nikon 24-70/2.8G in Sunlight]

 

Visible Light [f/11 for 1/250" @ ISO-320 with Onboard Flash and Baader UVIR-Block Filter]

 

Visible Light [f/11 for 1/250" @ ISO-320 with Onboard Flash and Baader UVIR-Block Filter]

 

Detail [from preceding photograph showing ciliate phyllary margins]

 

Ultraviolet Light [f/11 for 1/250" @ ISO-320 with SB-140 Flash and BaaderU UV-Pass Filter]

^{Some water on some of the flowers causes the bright specular reflections.}

^{Note UV-bright, hairy margins of the unopened phyllaries on the bud in the upper right.}

 

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