Re: [Aroid-l] Thorns on Aroids

From: <ju-bo at msn.com> on 2009.02.27 at 10:22:40 Dear Beth and All=2C Great idea=2C Beth! =3B Lots more research is needed by folks in the field=2C like you=2C Miss Beth to observe exactly WHY=2C for example=2C climbing Aroids don`t manage to ''stick'' themselves to the spiny trunk of a Ceiba tree. =3B Could it be additional factors beside just the spines=2C like rapidly peeling bark as the trunk of the tree expands which may discourage root attachment? By the way=2C thanks to Marek for reminding us of the sppines on Anchomanes (and this brings to mind Pseudohydrosme=2C a close (?) relative). We must also keep in mind the not-so-old but now extinct Magafauna=2C (through man`s hunting?)=2C and maybe other medium-to-small sized animals which until fairly recently existed through the Neotropics (and further North into N. America). =3B =3B These animals evolved together with the plants (which still exist)=2C so we really need to try to learn and understand what roles these now-extinct animals played in the evoloution of the defense mech. AND the distribution of fruit and seeds of these still existing plants. =3B Just yesterday I was reading about certain trees and plants on New Zealand which are today rare and growing rarer=2C the thoughts are that the now-extinct giant=2C Ostrich-like birds the Moas used to be responsible for the distribution of the seeds. =3B =3B When man came to these Islands=2C the Moas were rapidly hunted to extinction=2C together with a man-sized (!!)=2C Falcon-like bird=2C the Moas only natural enemy. =3B No more Moas (and no more Falcon-like-bird!)=2C LOTS of people=2C so no more seed distribution=2C no more trees. Good Growing=2C Julius From: desinadora@mail2designer.com To: aroid-l@gizmoworks.com Date: Mon=2C 23 Feb 2009 16:31:52 -0800 Subject: Re: [Aroid-l] Thorns on Aroids Dear All: Here's my two cents - a whole lot more plants than just the Aroids have thorns in our neotropical forests here in Ecuador=2C and usually it's to defend themselves from other plants. The spines on many of the other plants and trees are there to discourage competition from growing over them - for example=2C Ceiba pentandra has spines until about its 100th year to discourage colonisation by Philodendrons! (They're often the only smoothly empty plants in the forest=2C which makes them very easy to spot....) So any of the free-standing or vining aroids with spines may have them for the same reason - so as not to be overgrown by other ferns=2C orchids=2C or lianas. For directional spines=2C I'd look at the size of the plant and its relative habit - downward pointing ones would tend to me to indicate that the plant is trying to protect itself from invadors coming from below=2C while upward-pointing ones say "don't step on me." Lasia is an aquatic=2C as I understand it. I'd bet the spines are particularly sharp to dissuade wading birds and crocodilids from disturbing the mat=2C as well as to discourage anything that thinks it looks like a tasty snack.... It would probably only take one nasty festering thorn wound to keep me away from a plant like that! Then again=2C I grow a number of plants that do this to me on a regular basis=2C so maybe I'm not as smart as a heron! Beth ___ Date: Sun=2C 22 Feb 2009 13:03:14 +0000 From: <=3Bju-bo@msn.com>=3B Subject: [Aroid-l] Thorns on Aroids To: <=3Baroid-l@gizmoworks.com>=3B Message-ID: <=3BSNT102-W8FA7B67B7BC1BD58E6AF5FAB10@phx.gbl>=3B

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