Trifolium campestre [Pinnate Hop Clover]

[Andrea B.]

Blum, A. G. (2014) Trifolium campestre Schreb. (Fabaceae) Pinnate Hop Clover. Flowers photographed in ultraviolet and visible light. http://www.ultravioletphotography.com/content/index.php?/topic/930-trifolium-campestre-pinnate-hop-clover/

 

Synonyms:

• Low Hop Clover
  
• Trifolium procumbens sensu L.1755, not L.1753
  

Comment:

A key point of differentiation between T. campestre and the usually larger T. aureum is that the middle leaflet of the trifoliate leaf of T. campestre has a petiole which is longer than the petioles of the side leaflets. In T. aureum the middle leaflet appears sessile or on a very short stalk.

 

The banner petal of T. campestre is more conspicuously veined than that of the similar, but smaller T. dubium.

 

In Ultraviolet light the newer florets of Pinnate Hop Clover are UV-reflective. As they age and fold down, they become slightly darker. The veins are slightly darker than the rest of the petal.

 

Reference:

1. New England Wild Flower Society (2014) Trifoium campestre Schreb. Pinnate Hop Clover. https://gobotany.new...lium/campestre/

 

Set 1

Southwest Harbor, Maine, USA

10 July 2014

Wildflower

 

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

 

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

 

Visible Light [f/9 for 1/1250" @ ISO 400 with Nikon Df and 60/2.8G Micro-Nikkor]

Note the middle leaflet's petiole and the stipule.

 

Ultraviolet Light [f/11 for 15" @ ISO 400 with SB-14 UV-modified Flash and Baader UV-Pass Filter]

A long exposure was taken so that the UV flash could be fired 3 times for more even lighting.

 

Set 2

Southwest Harbor, Maine, USA

15 July 2008

Wildflower

 

Equipment [Nikon D200-broadband + Nikon 105mm f/4.5 UV-Nikkor]

 

Visible Light [f/11 for 1/250" @ ISO 400 in Sunlight with Baader UVIR-Block Filter]

 

Ultraviolet Light [f/11 for 1.5" @ ISO 400 in Sunlight with Baader UV-Pass Filter]