Doellingeria umbellata [Flat-topped White-aster]

[Andrea B.]

Blum, A. G. (2014) Doellingeria umbellata Miller (Asteraceae) Flat-topped White-aster. Flowers photographed in ultraviolet and visible light. http://www.ultraviol...ed-white-aster/

 

Southwest Harbor, Maine, USA

01 August 2014

Wildflower

 

Other Common Names:

• Tall White-aster
  
• Tall White Aster
  

Synonyms:

• Tall White-aster
  
• Aster umbellatus Miller
  
• Diplopappus umbellatus (Miller) Hooker
  
• Diplostephium umbellatum (Miller) Cassini
  

Comment:

D. umbellata is one of the first asters to appear along the Maine coast in mid-August heralding the beginning of the yearly fall aster parade which continues on into October. The plant can indeed be tall. I have seen the flat-topped white inflorescence at my eye level which is above 5 feet.

The variety found in Maine is the default species D. umbellata (Mill.) Nees var. umbellata.

Like many other asters in UV, the flowers are moderately UV-absorbing and have no marked central bullseye with respect to the outer ray flowers. However each disk floret appears to have a darker throat. The exserted stigma and fused stamens are UV-bright.

 

Reference:

1. New England Wild Flower Society (2014) Doellingeria umbellata. Tall White-aster.https://gobotany.newenglandwild.org/species/doellingeria/umbellata/

 

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

 

Visible Light [f/11 for 1/160" @ ISO 100 with onboard Flash and Baader UVIR-Block Filter]

 

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

A view of the involucres which are a key point in the identification of D. umbellata.

 

Visible Light [f/11 for 1/1.3" @ ISO 400 with onboard Flash and Baader UVIR-Block Filter]

Leaf blade top view. Note the brochidodromous venation.

 

Visible Light [f/11 for 1/2" @ ISO 400 with onboard Flash and Baader UVIR-Block Filter]

Leaf blade abaxial view.

 

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

A long exposure was used so that the UV-flash could be fired three times for more even lighting.

Please click the photo for a larger view.

 

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

A long exposure was used so that the UV-flash could be fired three times for more even lighting.

Please click the photo for a larger view.