In search for the true Tragopogon porrifolius

Tragopogon is a rather critical genus as far as its taxonomy is concerned.
Here in the Mediterranean there are at least two other species resembling T. porrifolius L., T. eriospermus Ten. and T. cupanii Guss. ex DC., the latter endemics to some southern Italian regions.

For a rather long time T. porrifolius and T. eriospermus have been confused. Instead, despite both having "purple" flowers and inflated scape below the capitula, the two species are rather easily distinguished:

Here the original description of T. eriospermus and the first drawing:

The type of T. porrifolius has been selected here:
and can be viewed here:

Most of the observations of T. porrifolius from North America refer to another taxon that is more similar to T. eriospermus:

In Europe it is just slightly better...

Maybe could it be worth revising the presence of the "purple-flowered" Tragopogon in North America?
To do this, apart photographing the capitulum and the scape below the capitulum, it would be useful to photograph:

1) leaves: undulate/not undulate at margins

2) phyllaries: reflexed/porrect at flowering

3) achenes when dried: achene body strongly narrowed into a very narrow rostrum or just slightly narrowed

4) habitat: dry or rather wet

Publicado el mayo 4, 2022 11:14 MAÑANA por blue_celery blue_celery


Publicado por truthseqr hace casi 2 años

Good to know a bit more about these...

Publicado por silversea_starsong hace casi 2 años

@blue_celery, are you saying that most of our observations are misidentified as T. porrifolius, when they should be T. eriospermus?

Publicado por truthseqr hace casi 2 años

I don't have the research chops to argue the divisions of species and subspecies, but iNaturalist generally follows Plants of the World Online for plants, and POWO shows Tragopogon eriospermus as now being called Tragopogon porrifolius subsp. eriospermus.

Interestingly, although all of my observations show Valerio (blue_celery)'s listed eriospermus characteristics for the ligules, phyllaries, and leaves, I can't think of ever seeing it in an environment that I'd call "rather wet".

Publicado por chris_nelson hace casi 2 años

Following up on my own comment, I don't know why iNaturalist's taxonomy doesn't match POWO in this case.

If Jepson and CalFlora are following the same references as POWO, it may explain why they show T. porrifolius as the species found in the SF Bay Area (although if that's true, I'm surprised that they don't list the subspecies).

Publicado por chris_nelson hace casi 2 años

@truthseqr I mean that what is identified as T. porrifolius in North America is strikingly different from ours and, at the same time, more similar to our concept of T. eriospermus. I would be curious to see the achenes but what can be seen in the Jepson eFlora is again similar to T. eriospermus.

Publicado por blue_celery hace casi 2 años

@chris_nelson POWO is a good reference but, in particular in this case, the use of the subspecific rank is inappropriate as the many differences are enough to justify the specific rank, at least in consideration of the average differences among the species of Tragopon.

With "rather wet" I did not mean with water persisting for a large part of the year but just "not dry meadows".

Publicado por blue_celery hace casi 2 años

@blue_celery Have you seen this draft taxon change? Might want to chime in with your input, if you think subspecies is inappropriate for these:

Publicado por graysquirrel hace casi 2 años

This paper looked at T. porrifolius in North America and noted that there may be another species present in North America that represents “T. longirostris, which is very similar in appearance to members of the T. porrifolius salsify clade(fig. 6), or some other purple-flowered species from the Majores clade”:

Publicado por andyjones1 hace casi 2 años

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