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Aloha,
Leland
--- Peter Boyce wrote:
> Hi Steve,
>
> The root tip thing is very interesting. While up at
> Batang Ai last week took some time to look closely
> at a very common species of Piptospatha and realized
> that the active root tip was always coated in cap of
> viscous gel; looking at root development it dawned
> on me that the gel was acting as an adhesive; as the
> root progressed across the rock the gel cap laid
> down a thin film, much the same as a slug or snail
> does, and the developing root hairs bound into this,
> gluing the root to the rock to the extent that
> attempts to remove older portions the root actually
> removed fragments of the rock (shale).
>
> The shoot tip thing is that the active shoot is
> attached to the older part of the stem by a line of
> weakness that functions as a point of potential
> disarticulation. When the river flow becomes to
> great such that the drag on the leafy portion has
> the potential to dislodge the entire plant, the
> leafy shoot breaks at the point of weakness and thus
> by sacrificing the active shoot/s the plan is able
> to reduce drag and thus prevent total dislodgement.
> The stumps remaining readily re-sprout, often
> forming multi-headed plants. Aside from 'saving' the
> mother plant the 'lost' active shoot tips frequently
> end up in a suitable environment for
> re-establishment and thus act as dispersal units.
> Another interesting aspect of this process is that
> the disarticulation point 'moves' with the extension
> of the active shoot and thus only the same size
> piece of active shoot is shed each time.
>
> Very best
>
> Pete
> ----- Original Message -----
> From: ExoticRainforest
> To: Discussion of aroids
> Sent: Monday, June 02, 2008 7:19 PM
> Subject: [Aroid-l] an apolgy if it is order
>
>
> Pete, this message from you is more valuable than
> I can make clear. I have several mentors who are my
> honest-to-goodness heroes and friends. And I hope
> you know you are one. Tom, Simon, Eduardo,
> Alistair, Julius, Leland and many others, a list too
> long to mention, help me all the time! My goal has
> been only to self-educate myself and to try to share
> what I learn in a way anyone interested in aroids
> can utilize. I am a writer who has been putting
> words on paper for over 30 years. But without
> accurate sources there is nothing to write!
>
> You have answered my questions many, many times
> and always help to make what I'm trying to
> understand clear. And that is at least in part the
> reason I quote all of you rather than trying to put
> what you teach in my own words. As a non-scientist
> my words are useless, but your words have value!
>
> So thanks for your kindness and your continued
> help. With the same thanks to all the professionals
> who teach me something new in their journals and
> emails on virtually a daily basis. If I could offer
> advice to anyone who is interested in aroids it
> would be to build a library of good scientific
> material on the genus. In the beginning the reading
> is difficult, but I time you will begin to
> understand the scientific terms and all those
> questions become clear answers.
>
> Now, a big request! Tell us about "the way roots
> glue themselves to rocks and how the shoot tips of a
> rheophytes resist water flow in spate." You just
> opened up a new file in my brain and I want to know!
>
> Steve
>
>
> Steve,
>
> I live in a country where we constantly struggle
> to get our students to read..... believe me...you
> can NEVER read too much. I have worked with aroids
> in one way or another for 30+ years; professionally
> for 20+ years... I read about aroids, any aroids,
> every day. And every day I learn something
> new...this week so far I have learned something new
> about pollination, the way roots glue themselves to
> rocks and how the shoot tips of a rheophytes resist
> water flow in spate. Tom, who has just tuned 70, has
> worked on aroids for over 40 years... he reads every
> day... Josef has worked on aroids nerly 50 years...
> he reads every day... and I would bet that they too
> are constantly learning new things.
>
>
>
>
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>
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