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smoke,
and
possibly
even
some
others
that
I
am
not
aware
of.
Having
said
that,
I
have
to
acknowledge
that
scientific
names
are
not
written
in
stone
and
are
subject
to
change
over
time
(it
should
be
noted
that
this
acknowledgement
will
likely
cause
me
much
grief
as
I
try
to
justify
to
my
plant
taxonomy
students
why
they
must
study
scientific
names).
Over
the
past
number
of
years
this
has
been
very
apparent
in
the
grass
family.
With
the
advent
of
new
technology,
researchers
have
re-classified
grasses
based
on
DNA,
chromosomes,
embryo
anatomy,
photosynthetic
pathways,
etc.
In
some
cases
certain
grasses
have
been
completely
renamed
and
until
everyone
is
familiar
with
the
new
name
synonyms
will
have
to
be
used
in
conjunction
with
the
currently
accepted
name.
My
initial
rationale
for
writing
about
plant
names
arose
from
a
discussion
with
a
student
about
milkweed
(Asclepias
spp.)
and
its
connotation
as
a
problematic
weed.
The
student
thought
as
a
result
of
the
weed
reference
in
its
name
that
it
had
to
be
an
introduced
plant
and
possessed
no
significant
beneficial
ecological
value.
According
to
the
Flora
of
Alberta,
there
are
three
species
of
milkweed
found
in
Alberta,
Low
or
Dwarf
(A.
ovalifolia),
Showy
(A.
speciosa),
and
Green
(A.
viridiflora).
Budd’s
Flora
of
the
Canadian
Prairie
Provinces
reports
four
other
species
of
milkweed
present
throughout
the
west,
Swamp
(A.
incarnata),
Silky
(A.
syriaca),
Hairy
(A.
lanuginosa)
and
Whorled
(A.
verticillata).
All
of
the
above
noted
species
are
actually
of
native
origin.
The
USDA
plant
web
site
lists
22
species
of
milkweed
present
in
the
U.S.
with
only
one
recorded
as
introduced/non-native.
Milkweed
species
in
general
possess
opposite
or
whorled
leaves.
They
vary
in
size
and
shape
from
small
narrow
linear
leaves
to
large
broad
obovate
leaves.
Milkweed
is
known
to
be
poisonous
to
livestock
and
wildlife.
They
contain
various
levels
of
cardiac
glycosides.
The
narrower
leaved
milkweeds
are
reported
to
be
more
toxic
than
species
with
broader
leaves.
One
of
the
more
common
species
of
milkweed
is
Showy
milkweed.
A
lethal
dose
of
this
milkweed
can
occur
if
an
animal
consumes
2
to
5
per
cent
of
its
bodyweight
in
plant
material,
whereas
a
narrow
leaved
variety
such
as
Green
milkweed
can
be
lethal
with
as
little
as
0.002
per
cent.
An
attribute
of
milkweed
that
ranchers
and
livestock
people
in
general
can
take
comfort
in
is
that
milkweed
has
very
poor
palatability,
and
unless
more
preferred
forages
are
not
available
animals
typically
do
not
consume
enough
milkweed
to
produce
lethal
levels.
Milkweeds
can
be
used
for
human
consumption
so
long
as
they
are
boiled
at
least
a
couple
of
times
and
the
water
is
changed
between
boiling;
the
cooking
neutralizes
the
poisons.
I’m
inclined
to
stick
to
spinach
to
obtain
my
daily
consumption
of
greens.
In
terms
of
neutralizing
poison
levels
it
should
be
noted
that
milkweed
remains
toxic
even
if
the
plant
is
dried
in
hay.
The
paradox
of
milkweed
is
that
it
serves
a
very
important
ecological
role
and
on
this
basis
the
weed
suffix
to
its
name
is
certainly
not
warranted.
The
Monarch
butterfly
(Danaus
plexippus)
requires
milkweed
leaves
to
lay
its
eggs
on.
The
Monarch
lays
the
eggs
on
the
underside
of
the
leaf
and
the
larvae
hatch
within
two
weeks.
The
larvae
feed
on
the
leaves
and
develop
into
caterpillars.
Milkweed
is
the
only
plant
that
the
larvae
will
consume
and
is
critical
to
the
survival
of
the
Monarch
species.
As
well,
the
Monarch
and
milkweed
plant
provide
us
with
an
example
of
commensalism
where
the
butterfly
is
able
to
obtain
nectar
and
feed
on
the
milkweed
without
concern
of
the
plant’s
toxic
properties.
In
fact,
the
Monarch
is
able
to
use
the
toxin
from
the
plant
as
a
defence
mechanism
for
itself.
Predators
that
eat
the
Monarch
butterfly
have
to
contend
with
the
same
toxins
as
those
that
are
present
in
the
milkweed
plant
itself.
Further,
the
Monarch
takes
part
in
one
of
the
longest
migrations
known
to
the
animal
kingdom.
All
Monarchs
must
make
a
flight
of
up
to
4,800
km
south
to
escape
cold
winter
temperatures.
Monarchs
east
of
the
Rocky
Mountains
travel
to
the
forested
mountains
in
Mexico
and
those
west
of
the
Rockies
travel
to
areas
along
the
California
coast.
Along
these
migration
routes
the
presence
of
milkweed
plants
is
obviously
critical
for
both
food
sources
and
reproduction.
The
large
scale
removal
of
milkweed
for
the
erroneous
purpose
of
reducing
weed
infestations
would
and
has
to
date
negatively
impacted
Monarch
populations.
So
what’s
in
a
name?
For
the
most
part
plant
names
are
very
descriptive,
but
occasionally
they
require
closer
inspection.
The
same
can
be
said
about
some
of
the
names
I
have
been
called
over
the
years.
Well,
okay,
maybe
some
of
them
are
warranted. Steve
MacRae
is
a
rangeland
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