Ludwigia octovalvis [Narrow-leaf Water Primrose]

[dancingcat]

Frary, S.C. (2022) Ludwigia octovalvis (Jacq.) P.H. Raven (Onagraceae) Narrow-leaf Water Primrose.  Photographed in ultraviolet and visible light.

 

Collected: 7 September 2022, creek bed margin, Waxahachie, Texas, USA.  Voucher deposited at the Botanical Research Institute of Texas, S. C. Frary [156].

 

Other Common Names:  Mexican Primrose-willow, Seedbox

 

Comment:  Not native to the US but commonly found along the Gulf of Mexico coast and inland southern US wetlands. Considered invasive in Florida.  Pretty 4-petalled yellow flower with very strong UV dark center.  Grows with roots submerged in shallow water, up to about 1 foot tall.  A very nice late summer wetlands wildflower.

 

Reference: Texas A&M University AquaPlant Database
 
Equipment [Olympus EM1mk2-broadband + Olympus 30mm f/3.5 macro]

 

In-Situ [iPhone]

 
Visible Light [f/11, iso 640, 1”, Kolari UV/IR Cut HotMirror Pro 2 filter, ambient indoor room light, in-camera 15-image stack].

Ultraviolet Light [f/11, iso 640, 5”, BaaderU filter, Kolari UV LED, in-camera 15-image stack]  

 

[KaJashey]

That a very nice stack and a great closeup of the flower.

 

 Does your setup give you UV false color?

[Andy Perrin]

It's an LED, KaJashey, so there wouldn't be much false color with it. 

[dancingcat]

@KaJasheyI haven’t tried UV outside in situ where I probably could get false color.. we have way too much wind for long outside exposure stacks, so I take the flower indoors under an LED or a flash painting setup where I have better control.  I take these photos for teaching and usually render them in b&w to avoid the “how can you get color with a uv filter?” sort of questions.  Really don’t want to go down that rabbit hole in a class of non-physicists . Its bad enough discussing what a bee might actually be rendering in its little bee brain….  I do like the Olympus in-camera stack.. its usually as good as Helicon or Zerene if the subject is relatively simple.

[colinbm]

Beautiful & clear images.

[Nate]

Nice images, the UV stands out well.