Jump to content
UltravioletPhotography

Calycoseris wrightii [White Tackstem]


Andrea B.

Recommended Posts

Blum, A.G. & Rørslett, B. (2015) Calycoseris wrightii A. Gray (Asteraceae) White Tackstem. Flowers photographed in ultraviolet, visible and infrared light. http://www.ultraviol...white-tackstem/

 

Ajo, Arizona

This Tackstem was growing in a weedy parking lot in Ajo, which is about 40 miles north of the US-Mexico border.

10 March 2012

Wildflower

 

Comment:

White Tackstem is a wildflower of the Southwestern US and Northwestern Mexico usually found in sandy, gravelly areas. The very similar Rafinesquia lacks the sticky glands which are present on the involucre and stem of this C. wrightii. The abaxial rays are often red-striped.

The Tackstem rays are moderately UV-absorbing and exhibit UV-bright pollen and anthers.

 

Reference:

1. Jepson eFlora (2015) Calycoseris wrightii. Jepson Herbarium, U. of Cal.-Berkeley, Berkeley, CA. http://ucjeps.berkel...IJM.pl?tid=1892

 

Set 1 by Bjørn Rørslett

 

CALY_WRI_G1203103389_VIS.jpg

Image reference: CALY_WRI_G1203103389_VIS

Visible light: NIKON D3X, 125 mm f/2.5 Voigtländer APO Macro-Lanthar lens, daylight

 

CALY_WRI_G1203104577_UV.jpg

Image reference: CALY_WRI_G1203104577_UV

Ultraviolet light: NIKON D40X, UV-Nikkor 105 mm f/4.5 lens, built-in Baader U2" (Venus) filter, SB-140 flash

 

The ligules (ray flowers) are extensively dusted by pollen, which is pale yellow and difficult to discern in visible light. In UV, however, the pollen grains are highly UV reflective and stand out against the moderately reflective floral parts.

 

The unopened buds are highly UV reflective so make a strong contrast to the opened flower heads.

 

Set 2 by Andrea Blum

 

Equipment [Nikon D300-broadband + Carl Zeiss 60mm f/4.0 UV-Planar]

 

Visible Light [f/11 for 1/2500" @ ISO-800 in Sunlight with Baader UVIR-Block Filter]

calycoserisWrightiiVisSun_20120310ajoAZ_140239pn.jpg

 

Ultraviolet Light [f/11 for 1/250" @ ISO-800 in Sunlight with Andrea-U UV-Pass Filter]

The Andrea-U UV-pass filter passes a small amount of violet/blue light which slightly alters the typical false colour appearance seen above in Rørslett's photograph. UV dark and light relationships are not changed.

calycoserisWrightiiUVAndreaSun_20120310ajoAZ_135857pf.jpg

 

The preceding photo after a slight turn of the colour wheel.

calycoserisWrightiiUVAndreaSun_20120310ajoAZ_135857pn01.jpg

 

Infrared Light [f/11 for 1/4000" @ ISO-800 in Sunlight with B+W 092 IR-Pass Filter]

calycoserisWrightii092IRSun_20120310ajoAZ_140026pn.jpg

 

Visible Light [f/8 @ ISO-400 with Nikon D3S + Nikon 60/4 Micro-Nikkor]

Details of the sticky tack-headed glands on the involucre and stem of C. wrightii. Dust and debris become caught in their sap.

calycoserisWrightii_20120310ajoAZ_12482701pf.jpg

 

calycoserisWrightii_20120310ajoAZ_124800pf.jpg

 

calycoserisWrightii_20120310ajoAZ_12483601pf.jpg

 

Visible Light [f/8 for 1/11250" @ ISO-400 with Nikon D3S + Nikon 24-70/2.8G AFS]

The abaxial rays show red stripes. It looks like a candy cane effect.

(Tucson, Arizona, 14 March 2012)

calycoserisWrightii_20120314tucsonAZ_125927pf.jpg

Link to comment
Hey, our first joint post - cool !! Let's do more of these and maybe we can finish up the desert wildflowers?
Link to comment

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now
×
×
  • Create New...