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In article ,
Cereus-validus... wrote:
I'm not talking about escaped plants from cultivation. I was referring to
the possibility of epiphytic species evolving naturally from other
species
already found in the area of the Pacific Northwest. The isolation of the
Olympic forest prevents any epiphytic flowering species from the far away
Southeastern US or Mexico from ever possibly migrating there. Any endemic
epiphytic flowering species would be unique to the region.

There are many species in the coastal flora of British Columbia that
also occur naturally in Kamchatka, Sakhalin and adjacent north Pacific
coastal areas. There are also a number of genera with closely related
species in similar areas on both sides of the north Pacific. The
distribution is an indication of climates during the interglacials,
when the two areas had a contiguous ecosystem.

I don't know how far down the west coast the temperate rainforest
extended during the glacials and interglacials, but during the last
glacial, most of the western US was much wetter than it is now. Even
10-20,000 years ago, most of the western US deserts were open forest
and grassland, with plentiful shallow lakes.

So not only was there a clear path for species to move from other parts
of North America, but also from temperate Asia. Of course, as Sean has
pointed out, epiphytes could readily have developed locally. I spent a
summer on the west coast of Vancouver Island long ago, and saw tree
branches densely covered with growing moss into which ferns and
flowering plants had rooted. I don't know if any of them were true
epiphytes, but it was certainly a great opportunity for a terrestrial
plant to evolve epiphytism. For that matter, I sometimes see
terrestrial flowering plants growing naturally in tree crotches here in
Toronto, a cold continental climate with a natural flora of deciduous
to mixed forest.

Btw, does anyone know if there are mistletoes native to the temperate
Pacific rainforest? These parasites are certainly common in moist
temperate areas in northern Europe. Or do parasitic plants that grow
on trees count as epiphytes?


On the south temperate coast of Australia mistletoe is common on Eucalypts.
Every back yard seems to have one.