• Ultraviolet Photography
  •  

Interesting ID Problem: Geum, Duchesnea or Potentilla?

29 replies to this topic

#1 msubees

    Zach Huang

  • Members
  • 389 posts
  • Location: Michigan, USA

Posted 29 June 2015 - 03:18

EDITOR'S NOTE: Zach, Bjørn and Andrea have all been working on this troublesome plant ID. The original post will be edited & re-placed in the appropriate section eventually. Some flowers are just really tough to ID!!

******************

Huang, Z.Y. (2015) Geum aleppicum? Jacq. (Rosaceae) Yellow Avens?. Flowers photographed in ultraviolet, visible light and simulated insect vision. http://www.ultraviol...m-yellow-avens/

Okemos, Michigan, USA
28June, 2015
Wild flowers in my back yard.

Comment:
Photographs taken in the order of visible light, ultraviolet, and simulated insect vision. Contrary to the white avens, this one has a dark spot at the base of each petal, which becomes green under insect vision. It is more similar to the other avens presented here.

Reference:
1. Wikipedia (28 June 2015) Geum aleppicum. Wikimedia Foundation, San Francisco, CA.

Equipment [Sony Nex7 + El Nikkor 80mm f/4.5 old format]

1. Visible Light [f/11 for 1/500" @ISO100, S8612 (2 mm thick), natural light, direct sunlight]
Posted Image

2. Ultraviolet Light [f/11 for 0.5" @ISO100, S8612 (2 mm thick) and ZWB1 (1.5 mm thick), direct sunlight]
Posted Image

3. Simulated Insect Vision [f/11 for 1/6" @ISO100, S8612 (2 mm thick) and UG 5 (1.5 mm thick), direct sunlight]
Posted Image

#2 msubees

    Zach Huang

  • Members
  • 389 posts
  • Location: Michigan, USA

Posted 29 June 2015 - 03:21

Strange, copying from another post suddenly stopped working...now toggling the editor modes (html and visual) does not change anything.

#3 Andrea B.

    Desert Dancer

  • Owner-Administrator
  • 4,813 posts
  • Location: USA

Posted 29 June 2015 - 03:55

I don't know what happened? I will check the Admin area for sql errors.

This flower might be a Duchesnea indica which has a yellow center.
Geum aleppicum has a green center.
Also check the similar Potentilla argentea.
Andrea G. Blum
Often found hanging out with flowers & bees.

#4 nfoto

    Fierce Bear of the North

  • Owner-Administrator
  • 1,836 posts
  • Location: Oslo, Norway

Posted 29 June 2015 - 13:36

Whatever this plant might turn out to be, it is *not* Potentilla argentea (a species with narrow and dissected leathery leaves shining white on their underside). However, it being another Potentilla is an open possibility. The emarginate petals are a trait frequently seen in Potentilla and to my best knowledge, not present in Geum (I was wrong as such shapes do exist, for example in G. chiloënsis, but not for G. aleppicum). Not familiar with Duchesnea as this genus is not native to Norway, though.

A picture of the basal foliage would be a great help in putting identification on the right track. Geum has very distinct shape of the lower leaves. Many species in Potentilla are defined by their rosette leaves.

It is worth mentioning that Geum aleppicum frequently cross with G. urbanum and in some regions, the hybrid actually is more numerous than the parents.

On a side note: Zach, you should really tag your files with a correct colour space to help them display properly. As of now they lack any specification thus default to sRGB.
Bjørn Birna Rørslett

#5 Andrea B.

    Desert Dancer

  • Owner-Administrator
  • 4,813 posts
  • Location: USA

Posted 29 June 2015 - 15:10

Yes, please embed an sRGB profile.

I'm going to put up my Duchesnea indica so that they can be used for ID along with our many Potentilla entries. A leaf is shown in the D. indica post. It is trifoliate like a strawberry leaf. D. indica has a Potentilla synonym. I'm not sure how it is currently classified. but my most recent New England flora keeps it as Duchesnea. That was incorrect. It is shown as P. indica in that flora. But other recent field guides do not have that.

An important point of identification in Potentilla, Duchesnea and similar flowers is the relative length of sepal to petal.

Still other very similar flowers found in genera Argentina, Comarum, Dasiphora, and Sibbaldiopsis.
Andrea G. Blum
Often found hanging out with flowers & bees.

#6 msubees

    Zach Huang

  • Members
  • 389 posts
  • Location: Michigan, USA

Posted 29 June 2015 - 15:15

Here is a photo of the leaves, I think these are near the flowers. I can do basal one tonight.

Posted Image
I thought I embedded the color profile in PN. But I think I may forgot it check it in photoshop since I res-aved it using PS to correct for exposure.

The strange thing of last night: normally the code here is [img] for images, and [b] for bold, but last night it became standard html tags "<img src". Initially when I copied straight from the web (not going to the editor), I got messages saying images were somewhere, but no
code. Then I used editor, and toggled to html mode, but the codes were totally different and did not work in my new post...I had to manually edit it.

#7 msubees

    Zach Huang

  • Members
  • 389 posts
  • Location: Michigan, USA

Posted 29 June 2015 - 15:27

Andrea,

Thanks. Mine might very well be the same species...I will need to resave all the files in photoshop with the embedding turned on and upload. Still this is easier than uploading to here (the old method). I see now there is only one way to link images externally? Is all Potentilla being renamed to a different genus?

View PostAndrea B., on 29 June 2015 - 15:10, said:

Yes, please embed an sRGB profile.

I'm going to put up my Duchesnea indica so that they can be used for ID along with our many Potentilla entries. A leaf is shown in the D. indica post. It is trifoliate like a strawberry leaf. D. indica has a Potentilla synonym. I'm not sure how it is currently classified, but my most recent New England flora keeps it as Duchesnea.

An important point of identification in Potentilla, Duchesnea and similar flowers is the relative length of sepal to petal.

Edited by msubees, 29 June 2015 - 15:29.


#8 Andrea B.

    Desert Dancer

  • Owner-Administrator
  • 4,813 posts
  • Location: USA

Posted 29 June 2015 - 15:32

Zach, sometimes there is a transmission error or a db error. Nothing to do but delete the glitch and start over. I corrected your link above.
Andrea G. Blum
Often found hanging out with flowers & bees.

#9 Andrea B.

    Desert Dancer

  • Owner-Administrator
  • 4,813 posts
  • Location: USA

Posted 29 June 2015 - 15:34

Argentina, Comarum, Dasiphora, Duchesnea, Potentilla and Sibbaldiopsis are the genera to search for this flower - after we see the basal leaves along with the stem leaves you posted. If your plant is extensive enough to have some mature examples, look for a small red strawberry fruit.

Here is a Key for this cluster: https://gobotany.new...key/potentilla/

At the start the key offers this choice:
Bractlets definitely larger than the sepals, with 3 conspicous teeth at the apex
OR
Bractlets of ± similar size as the sepals or smaller, lacking conspicuous apical teeth (though the margins may have small teeth)

So, this is *not* a D. indica (aka Potentilla indica) because the underlying bractlets as shown in Zach's Post #6 are not 3-toothed.

I'm going with P. norvegica at this point. QV: http://www.ultraviol...ian-cinquefoil/
Andrea G. Blum
Often found hanging out with flowers & bees.

#10 nfoto

    Fierce Bear of the North

  • Owner-Administrator
  • 1,836 posts
  • Location: Oslo, Norway

Posted 29 June 2015 - 17:01

"Still other very similar flowers found in genera Argentina, Comarum, Dasiphora, and Sibbaldiopsis".

No wonder as these genera all were once included in Potentilla ...

Andrea, the stem leaves shown by Zach do not appear like P. norvegica*. This might be P. intermedia or another Potentilla. We simply need to see the entire plant including the basal foliage.

*The funny factoid about P. norvegica is of course that this species is not native to Norway. Linné had a twisted sense of humour.
Bjørn Birna Rørslett

#11 Andrea B.

    Desert Dancer

  • Owner-Administrator
  • 4,813 posts
  • Location: USA

Posted 29 June 2015 - 18:59

Ternate leaf with two stipules put me near P. norvegica which has ternate leaf with two stipules.
However, in P. norvegica petals are shorter than calyx.
In Zach's flower, the petals are almost same length as calyx.
Andrea G. Blum
Often found hanging out with flowers & bees.

#12 msubees

    Zach Huang

  • Members
  • 389 posts
  • Location: Michigan, USA

Posted 29 June 2015 - 19:35

Wow..it is not easy with plant classifications! I would rather be studying bees :) :)

Edited by msubees, 30 June 2015 - 16:40.


#13 msubees

    Zach Huang

  • Members
  • 389 posts
  • Location: Michigan, USA

Posted 30 June 2015 - 01:38

here comes the photos.

1. very base. the large one had one leaflet missing, but they appear all trifoliate. one dried one also like this.
Posted Image

2. a bit up, still trifoliate.
Posted Image

3. hairy stem.
Posted Image

4. back of leaves.
Posted Image

#14 nfoto

    Fierce Bear of the North

  • Owner-Administrator
  • 1,836 posts
  • Location: Oslo, Norway

Posted 30 June 2015 - 08:27

I land on Potentilla intermedia. Flower appearance matches. Stem leaves are sessile or nearly so, which does not fit with P. norvegica but agree with P. intermedia.

As long as all differential characters are available, most plants are quite easy to identify.
Bjørn Birna Rørslett

#15 msubees

    Zach Huang

  • Members
  • 389 posts
  • Location: Michigan, USA

Posted 30 June 2015 - 14:20

Andrea and Bjorn,

so should I repost this one under a different name? (since I wont be able to change the URL name). or I can change the text now and Andrea can change the header-link. Thanks, Zach

#16 nfoto

    Fierce Bear of the North

  • Owner-Administrator
  • 1,836 posts
  • Location: Oslo, Norway

Posted 30 June 2015 - 15:19

I think we should do this as follows;

1. move the thread into the UV Informal forum and change title to something like 'identifying a plant in the Rose family'. Either Andrea or I can do that.
2. Repost the thread, labelled with the correct species, and without the back-and-forth posts, under Potentilla in UV Botanicals.
Bjørn Birna Rørslett

#17 Andrea B.

    Desert Dancer

  • Owner-Administrator
  • 4,813 posts
  • Location: USA

Posted 30 June 2015 - 15:25

Hi, I'm on now. I'll move this ID-ing thread to Informal with an Editor's note.
When we have all settled on an ID, the Zach can repost it in the Potentilla area.


Wow..it is not easy with plant classifications! I would rather be studying bees

Zach - I hear ya!! Potentilla is a particularly difficult genus. But we all have trouble with these IDs from time to time. Par for the course, as they say. Me, I find bumblebees difficult to ID in spite of their stipe patterns. :) :)
Andrea G. Blum
Often found hanging out with flowers & bees.

#18 Andrea B.

    Desert Dancer

  • Owner-Administrator
  • 4,813 posts
  • Location: USA

Posted 30 June 2015 - 16:42

OK, looking at the new fotos of the stem and lower leaves now.
I'm going to use the New England Flora Potentilla Key which does include P. intermedia.
There are some Potentilla in Michigan which are not in that key, but let's see what it gives us.

FIrst two steps.
  • (YES) Bractlets of +/- similar size as sepals and lacking conspicuous apical teeth(yes).
  • (YES) Flowers not solitary(yes). Stems erect (?guessing, but they do not appear to have come from a prostrate/trailing form.)
    Inflorescence with bracts(yes). Style thick near middle or base (?cannot see).
OK, now we hit a tough key point about the hairs on the underside of the leaf. So I will list both key points.
  • {A} Leaf blades sparsely to densely tomentose(no) OR long straight hairs(YES) OR merely curved(no) hairs on abaxial surface.
  • OR
  • {B} Leaf blades glabrous(no) OR pubescent with straight(YES) OR merely curved(no) hairs on the abaxial surface.
Following {A} leads to a measurement of style length/shape, petal length, filament length, anther length. YIKES!!
  • {C} longer styles 1.5-2.5mm, base conic, then filiform :: longer filaments 1.5 - 3.5mm :: longer anthers .7-1.2 mm
  • OR
  • {D} shorter styles .6-1.2mm, conic or columnar :: shorter filaments .8-1.5mm :: shorter anthers .3-.6 mm

Following {C} as a guess.

  • (YES) Leaflets sparsely tomentose abaxially, toothed with elongate triangular-lanceolate teeth 5-15mm long with sinuses between teeth usually extending 1/3-1/2 distance to midrib.
  • (NO) Potentilla gracilis
    Not our flower because its lower leaves have 3 leaflets and P. gracilis has 5 leaflets.

Following {D} as a guess leads to a dead end.

  • (NO) Lower leaves with 5-7 leaflets
  • OR
  • (NO) Lower leaves with 4-7 leaflets
Go back to {A} versus and take the {B} path.
Following {B}
  • (YES) Lower leaves with 3 leaflets
  • (YES) Plant not mat-forming.
  • (YES) Stem stiff-ish, coarse (not soft, bent). (I.e., stem hairs hirsute rather than villous.)
    And, petals 2-5 mm long (not 1.3-3 mm which are rather tiny).
  • Potentilla norvegica
**************************************

Now, do we really have P. norvegica? Let me add some missing information to convince Bjørn who would not have had access to all these tidbits in the European flora.

Reference:
Haines, A. (2011) Flora Novae Angliae. Yale University Press & New England Wildflower Society, New Haven & Framingham, MA.

Page 797: Potentilla norvegica L.
Our native North American race (ssp. monspeliensis) generally shows obovate leaflets and hirsute-type hairs on the stem (some high-elevation plants have ± glabrous stem, these recognized by some authors as var. labradorica). The European form (ssp. norvegica), which has been introduced to North America, generally shows oblong leaflets and fine hairs on the stem (Rydberg 1898). However, these differences are not absolute, and many researchers recognize a broadly defined Potentilla norvegica instead of multiple taxa.

Page 797: Potentilla intermedia L.
Considered to be a hybrid-derived species with Potentilla argentea and 
 P. norvegica as parents.

So, no wonder it was so difficult to ID this one!! Hybrids and non-Euro types!!
Whew....... :)

BTW, I am still not 100% sure of what we have here. Let's keep looking.

Reference:
Flora of North America for Potentilla norvegica, Vol. 9:
Leaves ternate, rarely palmate.
Bractlets 4-8mm. Sepals 5-8mm. (Andrea: so they can be the same length.)

Potentilla norvegica is considered native in both North America and Eurasia, with the American race occasionally recognized as subsp. hirsuta for the stiff hairs on the stems, petioles, and pedicels of most plants in the flora area. This feature and other purported differences between the two races, in addition to being relatively subtle and inconstant, can be found in both America and Eurasia, though undoubtedly at least in part as introductions.

An even greater challenge is determining native versus introduced ranges, especially given the likelihood that both native and Eurasian populations are widespread in North America. Achenes are produced prolifically and easily dispersed, to the extent that Potentilla norvegica is a contaminant in clover and hay fields and considered a weed at least in Canada (P. A. Werner and J. D. Soule 1976).

Reference:
Flora of North America for Potentilla intermedia, Vol. 9:
Basal leaves palmate or ternate (Andrea: aha!!!! So there could be basal ternate leaves.)
Cauline leaflets usually 5. (Andrea: but we do not have that.)
Bractlets .8-1.5cm. Sepals 3.5-6.5cm. Bractlets usually 2/3 x length of sepals, sometimes 1 x.

I think the preponderance of evidence falls to P. norvegica.

Perhaps Zach should label this one as: Potentilla cf. norvegica.

Comments? Question? Debate? :)
Andrea G. Blum
Often found hanging out with flowers & bees.

#19 msubees

    Zach Huang

  • Members
  • 389 posts
  • Location: Michigan, USA

Posted 30 June 2015 - 16:42

Andrea and Bjorn,

Thanks for the ID-ing!

Just noticed that the PN is not so perfect at all in copy settings to crop the same areas across different photos. The last one shifted....Or perhaps my camera shifted? i need to check that. and need to crop all 3 in similar areas.

Zach

#20 Andrea B.

    Desert Dancer

  • Owner-Administrator
  • 4,813 posts
  • Location: USA

Posted 30 June 2015 - 17:46

Michigan Flora: Potentilla Key
This key is not indented, so you have to look for the steps.

Useful key because it narrows things down to what Porentilla actually grow in Michigan.

1. Leaves all (except sometimes the uppermost bracts) palmately compound.
6. (yes) Principal leaves with only 3 leaflets.
7. (yes) Bractlets entire (very rarely 2-toothed at tip); receptacle not enlarging, dry.
Potentilla norvegica.

1. Leaves all (except sometimes the uppermost bracts) palmately compound.
6. (yes) Principal leaves with only 3 leaflets.
7. (NO) Bractlets of calyx with 3 (–5) teeth or lobes at summit; receptacle enlarging in fruit, becoming fleshy and red (as in Fragaria).
Potentilla indica aka Duchesnea indica. NOT Zach's flower.

I cannot answer all of the next portion of this key.
I get stuck on #8.
However 8a leads to P. verna, simplex and canadensis.
I know Zach's flower is NOT P. verna (curly hairs) or P. simplex (5-7 leaflets, when 3 then usually same length).
And P. canadensis is rare in Michigan. So I am going with 8b.
BUT, to continue with 8b, we have to agree to 5-7 leaflets which we do NOT have.

1. (yes) Leaves all (except sometimes the uppermost bracts) palmately compound.
6. (NO) Principal leaves (lower cauline and basal) with mostly 5 (–7) leaflets.
But we will continue anyway.
8a. Flowers on solitary peduncles; stem at first erect, becoming arching (or stoloniferous) and rooting at tip, or plants prostrate and mat forming, with stems rooting at the nodes.
OR
8b. Flowers in cymes; stems various, erect or prostrate to ascending, but without stolons and not rooting at tips or nodes.

If 8b, then
11. (yes) Leaflets not tomentose (though often glandular) or with fine to dense dull grayish tomentum besides long hairs beneath; achenes at maturity ± strongly rugose, with irregular curved ridges on surface.
13. (yes) Leaflets essentially green beneath; larger petals ca. 3–4.3 mm; longer anthers 0.3–0.6 mm long.
Potentilla intermedia - but we only got here by agreeing to 5-7 leaflets which we do NOT have.

Michigan Flora Key leads to P. norvegica.
Andrea G. Blum
Often found hanging out with flowers & bees.