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At 10:23 PM 08/06/2000 -0400, John Bois wrote:
It's not obvious to me what role bracken plays/played now or then. Stan,
could you spell it out a bit more. i thought this plant was limited in
its range--although I've heard of desert bracken.
Bracken is practically worldwide in distribution, and can certainly form
dense and extensive thickets. However, according to Stewart's "Paleobotany
and the Origin of Plants" (I only have the first edition, so this may be
out of date) the genus Pteridium, to which bracken belongs, is only known
from the Tertiary, though some Jurassic and Cretaceous fossils may be
assignable to the large and varied family Polypodiaceae to which it belongs.
That is not to say,of course, that ecological equivalents may not have
existed in the Mesozoic - given the absence of grasses I wouold be amazed
if there were no such plants. And of course bracken is not the only living
fern capable of providing concealment; Dicranopteris ferns form high, dense
and pretty much impenetrable thickets along forest edge in many tropical
areas, including Hawaii.
Ronald I. Orenstein Phone: (905) 820-7886
International Wildlife Coalition Fax/Modem: (905) 569-0116
1825 Shady Creek Court
Mississauga, Ontario, Canada L5L 3W2 mailto:firstname.lastname@example.org