Trifolium pratense [Red Clover]

[Andrea B.]

Blum, A. G. (2014) Trifolium pratense L. (Fabaceae) Red Clover. Flowers photographed in ultraviolet and visible light. http://www.ultraviol...nse-red-clover/

 

Southwest Harbor, Maine, USA

11 July 2014

Wildflower

 

Synonyms:

• Trifolium pratense var. sativum (P. Mill.) Schreb.
  

Comment:

Red clover is widely cultivated as a crop for nitrogen fixation and for feeding animals. It has naturalized across the US.

A key point of differentiation between T. pratense and the similar T. medium is that T. pratense's paired stipules are oblong and narrow abruptly to a bristly point. The leaf has a pale chevron marking.

In UV, like other Clovers, T. pratense is UV-dark with some brighter reflective areas dependent on the angle of the illumination.

 

Reference:

1. New England Wild Flower Society (2014) Trifolium pratense L. Red Clover. https://gobotany.new...olium/pratense/

2. Mittelhauser et al. (2010) The Plants of Acadia National Park. Red Clover, page 192. The U. of Maine Press, Orono, ME.

 

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

 

Visible Light [f/11 for 1/4" @ ISO 400 with onboard Flash and Baader UVIR-Block Filter]

 

Ultraviolet Light [f/11 for 20" @ 400 XXX with SB-14 UV-modified Flash and Baader UV-Pass Filter]

A long exposure was taken in order to use the UV flash three times for even lighting.

 

Visible Light [f/11 for 1/1.6" @ ISO 400 with onboard Flash and Baader UVIR-Block Filter]

Leaf with chevron and characteristic stipule.