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UltravioletPhotography

Sunflower?


Andrea B.

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I thought this was a Sunflower. But there are no UV-bright ray tips. It's all UV-dark!

 

Birna, ever seen a sunflower which is all UV-dark? This would be the first one I've ever seen if it proves to be a Helianthus.

 

I'm going to have to use the Flora Neomexicana, Part 2 (which weighs 4.7 pounds = 2.1 kilos) to try to research this.

 

These photo are quick conversions, not finished.

Cat hair courtesy of "Moka" who likes to make her contributions to my photography.

 

610_0014pn.jpg

 

610_0041pn.jpg

 

610_0026pn.jpg

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There are nectar guides, the tips of the "petals" (I know they aren't petals) are lighter than the center (you can see this better in the bottom-left corner). When I photographed my sunflowers, they didn't have a strong contrast in UV, although my camera had a limited UV reach.

 

There is surely some variability.

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But the rays (which are called the petals when the flower is in the Asteraceae family) of your sunflower are UV-brighter than the UV-dark center and the UV-dark proximal end of the rays.

 

I'm not seeing that at all with my flower above. I think the lower left corner is just a variation in amount of light?

 

I still like that photo of you in front of those 10-foot tall sunflowers.

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I'm not seeing that at all with my flower above. I think the lower left corner is just a variation in amount of light?

 

I am taking that back. :rolleyes: :grin:

 

Here is another photo of that flower and indeed there does appear to be a very small amount of less darkness on the tips of the rays. But I've just never seen a sunflower like this.

 

This is a white balanced conversion using a D610 color proifile.

 

610_0100pn.jpg

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Your "sunflower" still looks like a common sunflower. The petals (so this is their name?) have those UV-dark lines you find on "real" sunflowers too.

 


I will have to redo that selfie with the 10-foot tall sunflowers this summer, if I can plant them again. Hopefully with a better camera and better composition. I may even try UV, why not.

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Thanks, Bernard. It's good to have your example.

 

Cadmium, yes, my photos were made with the D610 + UV-Nikkor + BaaderU + SB14 flash.

The photos were made not made using the SB14. Just ambient light.

 

Here is a saturation/brightness push of my 2nd photo. This forces some false yellow to appear.

610_0100pnBGYPush.jpg

 

 

Here are some color samples from my 2nd photo. Please do not read too much into false color sampling with a 5x5 pixel color dropper from PS Elements !! Still, this kind of sampling does indicate the general yellow/blue palette of UV false colour. But the file has been jpeg-ed, so there can be some slight shifts of colour.

The flower rays are basically a very dark false yellow.

610_0100pnDots.jpg

 

 

OK, I'm thinking this must indeed be a Sunflower of some kind.

It is very INTERESTING :cool: :grin: to any amateur botanist/UV botanical photographer to find a flower which does not fit expectations. For the record all other wild Sunflowers which I have photographed in New Mexico have ray tips which are obviously brighter than the other part of the ray. I'll go get one of those to show you.

 

Here's an example. This is a Sunflower as it appears SOOC. Only crop and resize to post here.

helianthusAnuus_20200702laSecuela_21588.jpg

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Here you showed very well how much the UV false colors can vary: https://www.ultravioletphotography.com/content/index.php/topic/2201-three-sunflowers-three-filters-baaderu-kolariu-straightedgeu

 

But in this case you have something different. It isn't about false colors, it is about reflectance (darkness or "lightness"). Sunflowers really seem to have a great variability. They all look basically the same to our eyes, but can be so different in UV. This is really fascinating.

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Firstly, we cannot be certain this actually *is* a sunflower ie. a member of the genus Helianthus. The Asteraceae (Daisy Family) to which this specimen belongs is the largest of all plant families and there are numerous genera which superficially are the same to the eye. Differences are seen in the flower arrangements (ligulate ([rays] vs disk florets), details in the corolla and pappus, the fruits, presence and shape of chaff spaced between each floret, and the phyllaries which often are mistaken as the bracts. Then we have shape and arrangement of leaves along the stems, degree of hirsuteness and kind of trichomes found, whether the plant is perennial, biennial, or annual, and finally whether reproduction is sexual or asexual. To all this, factor in all the variability originating from horticultural breeding.

 

There are a great number of species in this family with bright yellow flower heads which turn out very dark in UV. Some have the outer fringe of the ray florets appearing a bit brighter, while for some the dark zone extends all the way to the tip of the ligule. My general impression is that the "UV dark" comprise a majority among the yellow species in this family.

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OK, I can do this, I'm pretty sure. I'm not afraid of a flora key. I just look things up as I go along when I don't know the terminology. And I owe it to Birna as her Best Amateur Botany Student to show I can still do this. :cool:

 

Flora Neomexicana III, Part II Dicotyledonous Plants

Edition 2, Copyright 2020

by Allred, Jercinovic, & Ivey

Print on demand, 2021, at Lulu.com

 

This is an impressive flora for the state of New Mexico. The illustrations by R. Ivey and the county range maps add to the usefulness of this flora. I had just bought the first edition when I moved here. As is typical of these things, the second edition came out shortly after. I plan to donate the first edition to my local library as it is a valuable reference book.

 

The volume begins with a Family Key, but I know already my flower is in the Asteraceae family because of its obvious morphology.

 

Here is an Asteraceae diagram from the Stanford Dahlia Project.

(It appears to be uncopyrighted, but I have provided a fair reference anyway. Always the safe thing to do.)

compositae_parts.gif

 

The Asteraceae Key, page 77, at a high level, places the Asteraceae flowers into 8 groups. It is easy to eliminate many of the groups.

 

Key A. Involucres conspicuously armed. NO.

No, an "armed" flower doesn't carry a little weapon. This means that the flower has thorns or spines or similar on the bracts underneath the corolla.

Key B. Leaves and/or phyllaries obviously dotted with translucent oil glands. NO.

 

You can see the involucre of my flower in the second photo of the first post above. The green, hairy involucre consists of several phyllaries.

 

It is difficult to hold this giant-@$$ book open while using it. I need some kind of clip. Oh well.

 

Key C. Corollas all ray like. NO. Or corollas bilabiate. NO.

Clearly my flower above has a central disk bearing little florets.

Many will recognize that this is where Dandelions (Taraxacum) belong.

Dandelions have no central disk of little florets.

 

Key D. Ray flowers absent (and more about pappus). NO.

Key E. Ray flowers absent (and more about pappus). NO.

Clearly my flower abve has rays around the central disk;.

Some Asteraceae have only a disk with no surrounding rays.

 

There. We have already eliminated 5 of those 8 groups.

 

The next three groups are all Ray Flowers Present with different descriptions of pappus for each group.

 

Review: Pappus. An Asteraceae disk floret has a modified calyx at the base of the corolla above the ovary which can look like a tuft of feathery bristles, papery leaf-like scales, or spine-like extensions called awns. You've all seen a Dandelion clock. The stuff which makes up that fluff is the pappus attached to the seeds.

Greek: πάππος meaning "old man".

 

KEY F. Ray Flowers Present. Pappus of Capillary Bristles, at least in part. NO.

These are the Asteraceae which produce a fluffy "clock" like the Dandelions after all the florets and rays dry up.

KEY H. Ray Flowers Present. Pappus Absent. NO.

 

At this point you will have to take my word for it that my flower above does not have any feathery, bristly pappus, but it does have a kind of leaf-like pappus under the little disk florets. I don't have photos showing that for the example above. But I will refer you to a Sunflower cut-away which I photographed a couple of years ago.

Three Sunflowers - Three Filters [baaderU, KolariU, StraightEdgeU]

The reddish pappus of that sunflower is shown in the 3rd photo in Post #10 and in all three photos in Post #11.

 

Thus we arrive at KEY G because my flower has scale-like pappus.

KEY G. Ray Flowers Present. Pappus of Awns of Scales. YES.

 

Easy enough so far, now the going gets tougher.

 

The first binary decision in Key G is to decide whether the Receptacle is Paleate or not.

The receptacle inside the involucre is the "basin" which holds the disk florets.

 

Review: Paleae, aka chaff. Dry scales or bracts growing from the bottom of the receptacle. I most often see the term 'palea' used for describing parts of a grass spikelet. The term 'chaff' seems more common for describing a receptacle.

 

Note that pappus and chaff emanate from two different parts of the Asteraceae flower. Don't confuse them.

sunny.jpg

 

 

Marching down the remaining part of this binary key, I'll spare you the decision process and the look-ups from now on. They begin to get a bit boring.

 

KEY G.1. Receptacles paleate. YES.

KEY G.1.2. Phyllaries, stems and leaves lacking black glandular hairs; phyllaries in 2-7 series. YES.

KEY G.1.2.3. Phyllaries and palae not transparent and striate. YES.

KEY G.1.2.3.5. Calyculi absent. YES.

...............No little leafies on the peduncle.

KEY G.1.2.3.5.10. Phyllaries persistent in fruit. YES. (I have photos.)

KEY G.1.2.3.5.10.12. Receptacles not columnar or strongly cone-shaped. YES.

KEY G.1.2.3.5.10.12.16. Ray florets not persistent in fruit and not papery. MOSTLY YES.

...............Most, but not all, dry up and fall off. I'm gonna go with YES here.

KEY G.1.2.3.5.10.12.16.19. Inner phyllaries not broadly obovate or orbicular. YES.

...............Pause to look up obovate and orbicular. In the photo above the inner phyllaries are elongated, not rounded.

KEY G.1.2.3.5.10.12.16.19.20. Rays 5 or more; leaves not linear to filiform, broader. YES.

 

Now I've reached a point where the decision depends on knowing whether the ray florets are sterile or not. And I don't think I know that about this flower. Hmmmm......we'll have to use some other reasoning.

 

KEY G.1.2.3.5.10.12.16.19.20.21.

 

IF ray florets are sterile and produce no seeds, then the possibilities are:

  • Simsia NO.
    • Range map does not include my county.
    • S. calva and S. lagasceiformis ligules too short.

    [*]Sidneya NO.

    • Range map does not include my county.
    • And, the plant is a compact rounded shrub.

    [*]Helianthus YES. The only one left standing.

    [*]Aldama NO.

    • Range map does not include my county.
    • Flowers have rusty stripes, 6-8 rays.

    [*]Viguiera NO.

    • Range map does not include my county.
    • V. dentata ligules are too short.

.

IF ray florets are fertile and do produce seeds, then the possibilities are:

  • Hymenopappus NO.
    • Ray florets 8.

    [*]Eclipta NO.

    • White corolla. Moist habitat.
    • Very short ligules 2-4 mm.

    [*]Engelmannia NO.

    • Ray florets 8-9.

    [*]Silphium NO.

    • S. lanciniatum very tall with large basal leaves.
    • S. integrifolium very rare and range does not include my county.

    [*]Wyethia NO.

    • W. arizonica out of range.
    • W. scabra has whitish stems. Phyllaries narrower, curve outwardly.

    [*]Verbesina NO.

    • I know this smelly Cowpen Daisy. My flower isn't it. :cool:

    [*]Helianthella

    • H. microcephala out of range and ligules too short.
    • H. parryi out of range and phyllaries lanceolate.
    • H. quinquenervis phyllaries lanceolate.
    • H. uniflora out of range and phyllaries lanceolate.

.

CONCLUSION: Helianthus

 

New Mexico has 11 Helianthus species only 4 of which can be found in my county. Plants do migrate over time, but I'll start with those 4 most likely possibilities and one more which ranges widely across the state.

 

The Helianthus key depends on knowing whether the plant is perennial or annual. I don't know that about my plant, so I'll have to work around that.

  • Plant perennial and leaves sessile or nearly so.
    • Leaves mostly alternate, folded and trough-shaped, arcuate downward.
      • H. maximiliani Maximilian Sunflower NO

      [*]Leaves mostly opposite, variously shaped but not as above.

      • H. ciliaris Texas Blueweed NO
        • Bluish-green foliage.
        • Ligules only 8-9 mm.

  • Plant perennial and leaves markedly petiolate.
    • Upper leaves mostly alternate.
      • H. nuttallii NO, based on lanceolate leaves..

.

At this point I'm down to two candidates both of which I know grow very locally and which must be annuals by process of elimination.

 

I have photos of the leaves, but the phyllary shape is enough to complete the ID.

Note that H. petiolaris seems to have variable leaves. Intergrades? Hybrids?

  • Plant annual and leaves canescent to whitish-tomentose on both surfaces.
    • H. petiolaris Prairie Sunflower NO, based on phyllary shape (below).

  • Plant annual and leaves glabrous to variously scabrous or short-hispid,
    but not canescent or tomentose.
    • Phyllaries ovate, abruptly narrowed to an acuminate tip, ciliate.
      • H. annuus Common Sunflower YES !!!

      [*]Phyllaries lanceolate, gradually tapering to the tip, not ciliate.

      • H. petiolaris Prairie Sunflower NO.

.

CONCLUSION: Helianthus annuus Common Sunflower

 

OK, that was time-consuming. I need to stay in practice though. And my particular H. annuus doesn't quite have the typical UV-signature we are used to seeing with Sunflowers, so I really did need to verify it through a flora key as best I could.

 

See you all tomorrow !!

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Bill De Jager

Firstly, we cannot be certain this actually *is* a sunflower ie. a member of the genus Helianthus. The Asteraceae (Daisy Family) to which this specimen belongs is the largest of all plant families and there are numerous genera which superficially are the same to the eye. Differences are seen in the flower arrangements (ligulate ([rays] vs disk florets), details in the corolla and pappus, the fruits, presence and shape of chaff spaced between each floret, and the phyllaries which often are mistaken as the bracts. Then we have shape and arrangement of leaves along the stems, degree of hirsuteness and kind of trichomes found, whether the plant is perennial, biennial, or annual, and finally whether reproduction is sexul or asexual. To all this, factor in all the variability originating from horticultural breeding.

 

There are a great number of species in this family with bright yellow flower heads which turn out very dark in UV. Some have the outer fringe of the ray florets appearing a bit brighter, while for some the dark zone extends all the way to the tip of the ligule. My general impression is that the "UV dark" comprise a majority among the yellow species in this family.

 

Birna, I'm not disagreeing with any of the above, but just looking at the flower as a whole my first guess was that it's in the Heliantheae tribe within the Asteraceae. At least here in the western U.S. a number of our genera within that tribe have flowers with a distinctive appearance that resembles a sunflower, as demonstrated by not just Helianthus but also Helianthella, Wyethia, Balsamorhiza, and Venegasia among others. There are some exceptions within the tribe, such as Madia and Ambrosia, that don't have this appearance.

 

Of course in the end there is no substitute for carefully working through a dichotomous key as Andrea has done so well here.

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Andrea: just pull up the plant specimen and look at the roots. A perennial species has heavy structures (rhizomes, rootstocks, well-developed tap roots and so on); annual species in general lack such structures as they need to start anew (from seeds or vegetative propagules) the next season.
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Yes, when I can do that I will. :lol:

Note: Don't do this on national or state park lands where plants must not be picked, dug up or otherwise harmed.

 

 

It's interesting what the field guides miss showing or describing which would confirm an ID.

And it's interesting what the flora keys omit given they must adhere to the binary methodology.

 

All three of the following

  • a full description of the plant and where it is found
  • a field guide with color photos, and
  • a key

are necessary for me to confirm an ID.

 

And there is an overall "impression" of a plant which often instantly identifies it.

The flower's "gestalt" I suppose we would call it??

 

As Bill points out, we can and often do get fooled by all those yellow Asteraceae we have out west.

Do you know that just in the last few years new Western US flowers have been discovered and named ? Lots of uninhabited land, lots of unseen plants.....pretty cool beans!

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