So what do you call the name Larix xmarschlinsii?
The name of a notho- (i.e. hybrid) taxon, more specificially of a hybrid
arising spontaneously in cultivation.

Iris Cohen schreef in berichtnieuws
So it is the same as xFatshedera lizei.
Now where do we put xCitrofortunella mitis (Calamondin)? Is there some
location where the natural habitats of tangerines & kumquats overlap, or did
it arise in cultivation in the distant past?

One of the interesting aspects of hybridizing, at least in orchids, is
that occasionally there is a registered artificial hybrid which is
subsequently discovered to be also a natural hybrid. The latter is published
by a botanical taxonomist, following which the poor plant is doomed forever
to carry two different names. According to RHS rules. If it is used as a
parent in hybridizing, it is called by the registered name. If the natural
hybrid discovery comes first, the plant only has one name, but it may be
written differently or carry a Latin ending.
Iris,

+ + +
Orchids have their own set of rules, but neither the ICBN nor the ICNCP, as
they stand, makes a distiction between natural and artificial hybrids. There
are just hybrids.
PvR

In article , P van Rijckevorsel
writes
http://www.botany2002.org/section11/abstracts/4.shtml
http://www.jaknouse.athens.oh.us/ferns/g_azol.html

It's not clear whether Aa. microphylla and mexicana represent one or two
hybridisation events. (Or even zero, depending on whether you accept the
position given in the first link,)

+ + +
I am not much on ferns, but I don't see anything on hybrids in these links?

From the first link

"we suggest the Azolla microphylla - mexicana lineage arose through
hybridization and homoploid speciation involving A. caroliniana and A.
filiculoides."
--
Stewart Robert Hinsley

http://www.botany2002.org/section11/abstracts/4.shtml
http://www.jaknouse.athens.oh.us/ferns/g_azol.html

It's not clear whether Aa. microphylla and mexicana represent one or
two hybridisation events. (Or even zero, depending on whether you accept the
position given in the first link,)

P van Rijckevorsel writes
I am not much on ferns, but I don't see anything on hybrids in these
links?

Stewart Robert Hinsley schreef in
From the first link

"we suggest the Azolla microphylla - mexicana lineage arose through
hybridization and homoploid speciation involving A. caroliniana and A.
filiculoides."
--
Stewart Robert Hinsley

+ + +
Ah yes, I must have fallen prey to the modern disease of being unable to
read text unless this is accompanied by a phylogenetic tree ;-)
PvR

Did I start all this?
Iris,
Central NY, Zone 5a, Sunset Zone 40
"The trouble with people is not that they don't know but that they know so much
that ain't so."
Josh Billings (Henry Wheeler Shaw), 1818-1885