In article <9609251844.AA26266 at BCC.ORST.EDU>, brunetj at AVA.BCC.ORST.EDU says...
> A student of mine is looking for the species name of a giant fern
>that secretes silica glass shards with poison, originates a long time
>ago, stands 6-18 feet tall, is touch sensitive and lives in Australian
>rain forests. Could anyone help? Thanks.
[Sounds like the botanical find of the century, if you've found one that
fits this description...]
There's no such beast, I'm afraid; it sounds like a very confused, garbled
combination of bits of several plants. Where exactly did he/she hear of it?
There are many types of tree ferns in rain forests of Australia and elsewhere
with stems taller than 18 feet, and a few other big ferns with long leaves
that get into your stated height range. There are also stinging nettle trees
[not ferns] with silicified stinging hairs [but not glass shards], and many
other types of poisonous plants and still other types of plants with silica in
cell walls or in intracellular crystalloid structures [none with macroscopic
shards of glass anywhere, however]. There are a few touch-sensitive plants
out there; the Venus' fly trap and Mimosa pudica are probably the most famous
[no ferns as far as I know]. Pretty much all plant groups originated a long
time ago in any human time scale of course, but if you mean traditional
"living fossils" then the true tree ferns and larger members of Marattiaceae
[fernlike plants of about the right size] or Equisetum spp. [isolated living
fossils famous for having silica in the cell walls, but not fernlike (except
in being pteridophytes) and mostly not that large] or cycads [some are trees,
they are palmlike or treefern-like, some are in Australia, some can be
poisonous if eaten] are your best bets.