„Please tell me how to collect, if I happen to find a colony next time I see Equisetum?“

Well, that is indeed an important question!

Since occurrence of genus Stamnaria, including asexually reproducing Titaeospora stage, seem to be rather rare in western part of USA, yet North America, any collecting person should avoid needless exploitation of infected horsetails, as well as the fungi.
In fact i don’t know about accurate frequency and sizes of horsetail populations being inhabited by (partially) parasitic genus Stamnaria, but let’s be cautious anyway.

Collecting itself is easy: cut aerial horsetail shoots right below lowest segment, named „internode“, which bears a usable stage of Stamnaria. After releasing vegetative and/or generative kinds of reproductive spores, the infected part and above will die anyway.
Thereafter do drie sampled parts in a dry room apart of sunlight, uncovered for a few days as water will evaporate freely, thus pieces not stapled but side by side. You may remove not infected internodes before, or therafter.

Please do only collect in case the horsetail occurrence appears not too small, and visible infections are not scarce, but numerous, to avoid exploitation of hosts and inhabiting ascomycetes. Otherwise it was preferable to try gathering well done photos so far. For sure decision concerning collections do depend on subjective estimation and evaluation, up to yourself.

What stage of fungus is usable at all?
In general, characteristicly blackened shoot segments may indicate infection by some Stamnaria. At close view, visible without magnification, there shall at least be clearly visible parallel splits along furrows of segments, where the rigid outer skin is slightly lifted, and sometimes hardly visible masses of spores ooze out.

This ist the first stage of use, as such vegetative conidia of Titaeospora type will prove true as member of genus Stamnaria, despite i might not identify distinct species‘ of. However, molecular analyzation and comparison might reveal specific ID in case of enough known sequences.

At later stage such fungi do break out small, for usual longitudinal pieces of epidermis, where masses of conidia and generative fruitbodies will be borne. Such pieces of skin do for usual adhere to shoot surface, caused little holes are visible then and thereafter, even when internodes are dead and bleached, the causing fungus has gone.

In best case, yet far too rare, you may find fully mature, cup-shaped fruitbodies, so named apothecia. These are bright yellow coloured and opened when soaked in water, ready to release their generative ascospores.
When dried, these do shrivel, colour changing to orange or orange brown. Rehydration goes the most quickly by adding water, so fruitbodies will soon start releasing spores in case of maturity.
Apothecia are short lived and will be grown seasonally, depending on species and climate.

I could identify such in case of sufficient maturity on characters of sporangia, so named asci, and spores borne within. So these could be sorted to species known to me, or as well get recognised as further knew detected species, sure it is possible.

Treatment of ready collection:
You could send ready samplings when segments got dried after some days, so these wouldn’t be destroyed by mould fungi. Perhaps you do know scientific institutions who liked to identify specimen and to preserve in their collection.
I surely shared my knowledge to ensure right ID according to my experience, as several species‘ known to me are still not published, and many preserved specimen are wrongly identified for lacking knowledge and usual mixings up.

Another chance was sending to me for ID and sharing with botanical institutions, still i need equipment like microscope, or to visit a propper instituion at university myself.

Just do ask me in case of further questions i missed to answer here.

Best regards and wishes
Erwin Gruber

Posted on 24 March, 2020 10:21 by erwin_pteridophilos erwin_pteridophilos


ok, thanks !
: )

Posted by radekwalkowiak over 3 years ago

Yes I will be happy to contribute, thanks for letting us know

Posted by owenclarkin over 3 years ago

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