Jump to content
UltravioletPhotography

Pilosella caespitosa [Field Hawkweed]


Andrea B.

Recommended Posts

Blum, A.G. (2014) Pilosella caespitosa (Dumort.) P.D. Sell & C. West (Asteraceae) Field Hawkweed. Flowers photographed in ultraviolet and visible light. http://www.ultraviol...field-hawkweed/

 

Southwest Harbor, Maine, USA

07 July 2014

Wildflower

 

Synonyms:

  • Hieracium caespitosum Dumort
  • Hieracium pratense Tausch
  • King Devil
  • Yellow King Devil
  • Yellow Hawkweed

Comments:

The tightly clustered capitula of P. caespitosa provides for an easy identification of this plant.

 

Field Hawkweed's UV appearance differs considerably from the other Pilosella we have photographed so far in that it has only a very small central UV-dark area while the rays are quite UV-bright. We had initially thought that the almost uniformly UV-dark appearance seen in Pilosella peleteriana and Pilosella aurantiaca might indicate another way of separating Pilosella from Hieracium, but clearly that UV-dark signature does not appear across all Pilosella species.

 

References:

1. New England Wild Flower Society (2014) Hieracium caespitosum. Yellow Hawkweed. https://gobotany.newenglandwild.org/species/hieracium/caespitosum/

 

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

 

Visible Light [f/32 for 1/25" @ ISO 100 in Sunlight with Baader UVIR-Block Filter]

pilosellaCaespitosaVis_070714swhME_19614pnCrop.jpg

 

Visible Light [f/22 for 1/15" @ ISO 100 in Sunlight with Baader UVIR-Block Filter]

pilosellaCaespitosaVis_070714swhME_19749pnCrop2.jpg

 

Visible Light [f/11 for 1/20" @ ISO 100 with onboard Flash and Baader UVIR-Block Filter]

Aphids and a spittle bug nymph inside the white bubbly spittle (to the right) enjoy the flower.

pilosellaCaespitosaWithSpittleBugsVisFlash_070714swhME_19644pn.jpg

 

Ultraviolet Light [f/16 for 1/30" @ ISO 400 with SB-14 UV-modified Flash and Baader UV-Pass Filter]

Stigmas are UV-dark.

pilosellaCaespitosaUVBaadSB14_070714swhME_19655pnCrop.jpg

 

Ultraviolet Light [f/16 for 1/30" @ ISO 400 with SB-14 UV-modified Flash and Baader UV-Pass Filter]

Unopened rays are UV-dark.

pilosellaCaespitosaUVBaadSB14_070714swhME_19760pnCrop.jpg

 

Ultraviolet Light [f/11 for 1/30" @ ISO 400 with SB-14 UV-modified Flash and Baader UV-Pass Filter]

UV-dark aphids and UV-white spittlebug spittle.

pilosellaCaespitosaWithSpittleBugsUVBaadSB14_070714swhME_19675pn.jpg

Link to comment
  • 1 year later...

SET 2

Shore Cottage, Southwest Harbor, Maine, USA

22 July 2015

Wildflower

 

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

 

Visible Light [f/11 for 1/200" @ ISO-200 in Sunlight with Baader UVIR-Block Filter]

pilosellaCaespitosumCluster_visSun_20150722shoreCottageME_35852pnPf.jpg

 

Ultraviolet Light [f/11 for 1/2" @ ISO-200 in Sunlight with BaaderU UV-Pass Filter]

pilosellaCaespitosumCluster_uvBaadSun_20150722shoreCottageME_35858pnPf.jpg

 

Ultraviolet Light [f/11 for 1" @ ISO-200 in Sunlight with CopperU UV-Pass Filter]

pilosellaCaespitosumCluster_uvCopperSun_20150722shoreCottageME_35876pnPf.jpg

 

Simulated Bee Vision [f/11 for 1/10" @ ISO-200 in Sunlight with UG5 + S8612 Stack]

The yellow, UV-absorbing areas of the rays would probably stimulate the bee's green receptor.

With this filter stack, these areas are the darker green in this photo.

The yellow, UV-reflecting areas would stimulate both the bee's green and UV receptors.

With this filter stack, these areas are the lighter green yellow in this photo.

pilosellaCaespitosumCluster_ug5s8612Sun_20150722shoreCottageME_35878pnPf.jpg

 

Infrared Light [f/11 for 1/60" @ ISO-200 in Sunlight with B+W 093 IR-Pass Filter]

pilosellaCaespitosumCluster_093IrSun_20150722shoreCottageME_35890pn.jpg

Link to comment

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now
×
×
  • Create New...