Tetraneuris scaposa [Four-nerve Daisy]

[dancingcat]

Frary, S. C. (2023) Tetraneuris scaposa (D.C.) Greene (Asteraceae) Four-nerve Daisy. Flower photographed in visible and ultraviolet light.

Collected at the Mockingbird Nature Park, Midlothian, Ellis Co. Texas, USA.  Voucher deposited at the Botanical Research Institute of Texas, Fort Worth Botanic Garden (S. C. Frary #172, 2023-05-18).
 
Synonyms:
* Stemmy Four-nerve Daisy
* Plains Yellow Daisy
* Bitterweed
* Yellow Paper-Flower
* Hymenoxys scaposa (DC) K.L. Parker

 

Comment:
Common throughout the US Great Plains in spring and summer, growing on limestone prairie and rocky hillsides.  Leaves have a resin-like substance with a bitter taste, hence the common name “Bitterweed”.  The center is strongly UV dark up into a third of the petal length.
 
Reference:
Lady Bird Johnson Wildflower Database, University of Texas at Austin

 

Equipment: [Olympus EM1mk2-broadband + Olympus 90mm f/3.5 macro]

In situ [iPhone]

Visible Light [f/6.3, ISO 200, 1/6 sec. with KolariVision hot mirror pro 2 filter, 15-image in-camera stack]

 

Ultraviolet Light [f/6.3, ISO 200, 2.5 sec. with BaaderU filter, UV Beast LED, 15-image in-camera stack]

[Andrea B.]

I found that the adaxial side of Tetraneuris acaulis quite nicely showed the 4 "nerves" in UV when. For Asteraceae, the adaxial side is sometimes surprisingly different than the top side in UV.

 

Here is another interesting example - a Rudbeckia which shows false yellow on top but false blue on the back. Rudbeckia.