• Ultraviolet Photography
  •  

Anthemis arvensis or Tripleurospermum inodorum

4 replies to this topic

#1 Andrea B.

    Desert Dancer

  • Owner-Administrator
  • 7,351 posts
  • Location: USA

Posted 25 July 2019 - 23:04

These white flowers are between 1 - 1.5" (3 - 4 cm) in width. I attempted to key it but got stuck on determining whether or there was "chaff in the receptacle" or not. Depending on that determination, this will be either an Anthemis arvensis or a Tripleurospermum inodorum both of which are confusingly commonly named Corn Chamomile. (The US has no standardized common names. Too many wildflowers, many of which have no common name at all yet.)

I think that there is no "chaff", but I'm posting this for Birna or anyone else to look at and give me their opinion.


This foto will click up to 1000 pixels wide.
Attached Image: 610_7270pn.jpg
Andrea G. Blum
Often found hanging out with flowers & bees.

#2 nfoto

    Former Fierce Bear of the North

  • Owner-Administrator
  • 2,321 posts
  • Location: Sørumsand, Norway

Posted 26 July 2019 - 04:59

A pity we don't see the phyllaries, whether stem is glabrous or hairy, and the foliage, as the distinction between the various alternatives sometimes isn't obvious in a photo.

The "chaff" actually is made up by modified sepals surrounding each individual floret in the flower head of a Compositae species. For the Anthemis, it looks like this (From linnaeus.nrm.se/flora/di/astera/anthe/antharv2.jpg): The barbed hyaline thingies are the chaff. They typically are merged with the flower as it becomes a fruit ('achene' or 'capsyla', terminology differs) to act as helpers in fruit dispersal.

Posted Image

Hopefully Andrea has more photos of her enigmatic plant.

My gut feeling is Tripleurospermum inodorum (Scentless Mayweed) as it tends to be the most frequently occurring of these two, at least over here in Europe. Another candidate is Matricaria recutita (the 'true' Chamomile).

#3 Andrea B.

    Desert Dancer

  • Owner-Administrator
  • 7,351 posts
  • Location: USA

Posted 26 July 2019 - 14:50

I've settled on Tripleurospermum inordorum because of the leaves of my specimen. And now that you have shown me a good chaff photo, I can see that my flower has no chaff.

Keys can be soooo annoying. The dichotomous key for Tripleurospermum versus Anthemis does not mention leaves at all. And it is immediately obvious when looking at T. inordorum and A. arvensis that the leaves are completely different.

It is not the true Chamomile because the flowers are too large.

Some more photos to follow.
Andrea G. Blum
Often found hanging out with flowers & bees.

#4 Andrea B.

    Desert Dancer

  • Owner-Administrator
  • 7,351 posts
  • Location: USA

Posted 26 July 2019 - 15:14

abaxal T. inodorum

The stem is glabrous, slightly ridged.

I don't know why this photo looks so unsharp? Oh well.
Attached Image: 610_7251pn.jpg
Andrea G. Blum
Often found hanging out with flowers & bees.

#5 Andrea B.

    Desert Dancer

  • Owner-Administrator
  • 7,351 posts
  • Location: USA

Posted 26 July 2019 - 15:20

Note filiform leaves in the background.

Attached Image: tripleurospermumInordorum_vis_ambient_20190725shoreCottageSwhME_16139pn.jpg
Andrea G. Blum
Often found hanging out with flowers & bees.