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We did the Amsinckia grandiflora census the other day. My
coworker and I flagged all the flowering plants we could find couple of
weeks ago, because the plants we saw were all really small and we didn't
know how long they would stay in flower. We were hoping that it was just
the smallest ones that were flowering and that if we waited, the larger
ones would be flowering. But there were no larger ones, so we waited too
long. A good-sized Amsinckia plant is 25-35cm tall, with
several branches. Most of the ones this year were less than 15cm with no
branches. That's too small to produce any seeds. To find them, we pretty
much had to just look for the flags and then hunt around for the plant near
each flag. Then we measure the plant, check its floral morph (see below),
and record its nearest neighbor to get an idea of the community
composition. If any of you are wondering how our survivorship tracking
went - most of the plants we marked ended up being Amsinckia
tessellata, but we did get about five A. grandiflora
plants flowering out of the 100 total plants we marked in November. This
may seem like not very much, but last year we ended up with only one
A. grandiflora plant in flower.
There was a lot of owl's clover (Castilleja exserta)
flowering. It's purple, but I found an all-white mutant. Chinese
houses (Collinsia heterophylla) had sprung up since our last
visit. The opposite hillside to our experimental population was bright
purple with Phacelia a few weeks ago, but it has now all
dried out. Things are moving fast. It's been windy with no rain, so
things are senescing rapidly.
I mapped lupine bushes at the native Amsinckia population.
Ten years ago there was a single lupine (Lupinus albifrons)
at that site, but now there are over 30 bushes. There has been a
corresponding decrease in A. grandiflora with the increase in
lupine and we're trying to figure out how they are related. Since
lupines are nitrogen fixers, they can feed annual grasses,
making them larger and more competitive. Amsinckia doesn't
do well against annual grasses. But removing the lupine may
not help - there's evidence that the effects of the nitrogen fixing remain
for several years, even after the lupine is gone. This
lupine has a short life cycle (5-7 years) and we are already seeing
some die-back of the larger plants. We were hoping to see the
lupines disappear, but I saw some smaller plants growing while I was
mapping - I wonder if maybe the lupines are here to stay...
So, what's the deal with floral morph?
Amsinckia grandiflora plants have two morphs: some plants
have the stigma protruding from the center of the flower tube. It looks
like a pin head right in the middle of the flower. These plants are called
"pin" plants. The flowers are bisexual, though, the anthers are just very
low in the floral tube so you can't really see them. There is another
morph called "thrum", where the anthers are right at the top of the floral
tube and the style is very short so you can't see it. Plants in the
Boraginaceae (borages) often have multiply-morphed flowers. In
A. grandiflora, all the flowers on the same plant are the
same floral morph. In other borages, a single plant can have
different flower morphs on it. A. grandiflora is known as a
distylous plant species because the style has two possible lengths. Other
borages are tristylous, with three possible style lengths. Still
others have uni-sexual flowers.
If you ever want to see pictures of the plants I talk about in these entries, most of them can be found here:
http://elib.cs.berkeley.edu/photos/flora/
Want to know what some of these flower parts are? Check out The Perfect Flower
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