Holothrix in the George area

@tonyrebelo @jeremygilmore @justinponder2505 @ren_hoekstra @malthinus @sedgesrock @milewski @christiaan_viljoen

Today I have a challenge- a question that needs answering. Here it is:

Many people have noted the odd forms of Holothrix in the Outeniquas/George area, in particular H. brevipetala, H. exilis and H. villosa var. condensata. They grow long, slender, reed-like peduncles/stalks and the flowers are well spaced on the inflorescence.

As examples-
Villosa var. condensata:
https://www.inaturalist.org/observations/107879164
https://www.inaturalist.org/observations/102705460
https://www.inaturalist.org/observations/10825517
A more robust form: https://www.inaturalist.org/observations/107879163

Brevipetala:
https://www.inaturalist.org/observations/11188064
https://www.inaturalist.org/observations/11188047
https://www.inaturalist.org/observations/21943295
https://www.inaturalist.org/observations/104707154

Exilis- records very sparse:
https://www.inaturalist.org/observations/11224432

Now- the usual forms:
Villosa var. condensata:
https://www.inaturalist.org/observations/104722684
https://www.inaturalist.org/observations/104190741
https://www.inaturalist.org/observations/11171000

Brevipetala:
https://www.inaturalist.org/observations/103585361
https://www.inaturalist.org/observations/59859659
https://www.inaturalist.org/observations/80237415

Exilis:
https://www.inaturalist.org/observations/11233801
https://www.inaturalist.org/observations/17320561

The obvious question is "Why do they grow like this here and only here?"
In brevipetala the tall form seems to extend along the Cape Fold Mountains, but the reed-like form of exilis is rare and sporadic, and villosa var. condensata is even more patchy, though locally common in spots.
We should attempt to answer this question by asking "What is different about the Outeniquas?"
In other words....
Do the pollinators fly higher?
Is the weather more ideal for such growth?
Is there less wind?
Etc...

Any suggestions?

Posted on Μάρτιος 04, 2022 1211 ΜΜ by ludwig_muller ludwig_muller

Σχόλια

??
Rain all year instead of only in winter.
Not as hot (and dry) in summer.
its in the styx: no need to hide from predators.
Its in the styx: species depauperate area: fewer competing.
orchid and other species - so can be more flexible.

Αναρτήθηκε από tonyrebelo περίπου 2 χρόνια πριν

Thanks for your ideas @tonyrebelo !
I made a guess on wind because of the differences between the short condensed H. v. condensata from CT, which has the Cape Doctor, and the populations I found in the Outeniquas, which experienced much less wind.

Αναρτήθηκε από ludwig_muller περίπου 2 χρόνια πριν

I am certain that the Outeniquas are as windy and with as strong winds as the Peninsula.
But there are too many confounding variables - even geology is subtly different (finer sediments).

Αναρτήθηκε από tonyrebelo περίπου 2 χρόνια πριν

@ludwig_muller Hi Ludwig, Many thanks for posing this interesting question. I see that you posted this two weeks ago, and you linked it to @milewski. However, for some reason it did not pop up for me, and I found it only because I happened to visit your Journal this morning. I wonder why the linking mechanism did not work. With regards from Antoni

Αναρτήθηκε από milewski περίπου 2 χρόνια πριν

Προσθήκη σχόλιου

Συνδεθείτε ή Εγγραφή για να προσθέσετε σχόλια