Decorated Involucre

[MWP admin]

I came across this plant with really nice involucres. Capitulum rayless. Disc florets yellow. Seeds with pappus. Leaves fleshy.

See pics below

I think it is Phagnalon species, probably Phagnalon graecum subsp. ginzbergeri

[IL-PINE]

I agree with you and I have taken similar photographs recently.

[MWP admin]

Phagnalon spp. confirmed!


The thing is that Wild Life says that there is a related species , Rock Phagnalon or Phagnalon rupestre or Phagnalon tenorii where the involucral bracts (flaps) are more rounded. Now seeing your pic, the bracts of yours are quite elongated. Also the disc florets are not as dense in numbers per flowerhead as your pic and other pics I saw!

The bible distinguishes from the two by the bracts as follows:

P. graecum = narrowly triangular to linear-lanceolate; acute (narow)
P. rupestra = Ovate to triangular; obtuse (broad)

So we ned to do ore research here!

[IL-PINE]

On a second look there seems to be a difference! On first glance I thought they were identical

[Edwin Lanfranco]

Stephen's Phagnalon is P. rupestre. It is somewhat less frequent than P. graecum from which it differes by having rounded involucral bracts.

[MWP admin]

I am trying to sort this Phanaglon and I have difficult to determine if the involucral bracts are of P. rupestre or P. graecum ??!!

The lower phyllaries are rather ovate bit the upper ones elongate, though none are pointed (triangular)

What's your opinion?

[MWP admin]

For instance the specimen below is clearly P. graecum with narrow and elongated phyllaries compared to the photos of the prev example.

[jackpot]

However, this is P. graecum now, having not the rounded involucral bracts at the tip

[MWP admin]

I know that the last image is P. graecum, but do you confirm that the previous 2 photos are P. rupestre? The 2 specimen where found close to each other in Wardija. Somewhere I read that P. rupestre is unfrequent in Malta.

[jackpot]

I would say 50% graecum and 50% rupestre (anyway, I am not really convinced about the status of separated sp. or ssp)- this needs more observations

[RB]

Sometimes I am confused about separation of species. Why for some plants, very minor differences are a new species, for others, not.

For example - Mathiola incana and the ssp melitensis.

They are, in my opinion, substantially different.

This year, I grew some M i and then M i m from seeds. Apart from the seeds being notably different, even the seedlings, from the cotyledon stage, and small plants, at every stage even a fool can tell that they are different.

In fact, when I collected the melitensis seeds, I did not have any idea whether they were melitensis except a small suspicion about the seeds, and from where they were collected. Once they germinated, immediately I said "hey - we have something different here" - it was so obvious.

Yet melitensis is only a sub-species.



RB

[MWP admin]

Good observation, I have commented this somewhere else on the forum. Probably it is a matter of how convincing are the authors to seperate two quite similar species in an own species taxon or into a subrank subspecies level.

Some mention the DNA analysis, but my common sense says that the more differences there are in the phenotype (eg Mathiola incana vs Mathiola incana subsp. melitensis) the more different should be the karyotype (genetic material).

Also, certain differences that for us are minor, for botanists they are important, while other more conspicuous differences (like flower colour of the Anagallis arvensis) are not considered botanically important.

But like you, I think is not really scientific how the line is drawn, and it is quite subjective. Thanks to modern karyotyping, things are changing in a more scientific approach, hence the numerous taxon changes during the last decade.

[MWP admin]

I really like this plant...