Home |
Search |
Today's Posts |
#1
|
|||
|
|||
poisonous seed dissemination?
Last week, my wife and I were walking through the eastern Iowa woods
and noticed a few small trees with lustrous red berries. They were beginning to wither, and most of the other deciduous trees had dropped their leaves. This got me to thinking: What function do the poisonous berries serve? I would assume there's some animal that can digest them and disseminate the seed, but then why were the berries withering on the vine? Is this a sign of a missing bird species (e.g., a bird species fallen prey to the West Nile virus)? Against that idea, I seem to recall often seeing such bushes full of untouched fruit. What gives? Thanks in advance, A nonbotanist dilettante |
#2
|
|||
|
|||
poisonous seed dissemination?
Last week, my wife and I were walking through the eastern Iowa woods and
noticed a few small trees with lustrous red berries. What function do the poisonous berries serve? What makes you think they are poisonous? Maybe they are Viburnum, which the birds will eat later in the winter. I am still trying to figure out the purpose of Callicarpa berries, which were apparently one of those random mutations that people love to puzzle over. Iris, Central NY, Zone 5a, Sunset Zone 40 "The trouble with people is not that they don't know but that they know so much that ain't so." Josh Billings (Henry Wheeler Shaw), 1818-1885 |
#3
|
|||
|
|||
poisonous seed dissemination?
Iris Cohen schreef
I am still trying to figure out the purpose of Callicarpa berries, which were apparently one of those random mutations that people love to puzzle over. Iris, + + + Callicarpa does not have berries, but drupes. I am wondering if the blue color is somehow connected with this. Prunes also tend to be blue and also are drupes. Just idly wondering. PvR |
#4
|
|||
|
|||
poisonous seed dissemination?
Our Callicarpa berries are anything but blue. They're a particularly
vivid shade of screaming pinkish-purple, a color not found elsewhere in nature, I think, except in orchids and some tropical fish. Monique P van Rijckevorsel wrote: Callicarpa does not have berries, but drupes. I am wondering if the blue color is somehow connected with this. Prunes also tend to be blue and also are drupes. Just idly wondering. PvR |
#5
|
|||
|
|||
poisonous seed dissemination?
The black to purple berries of deadly nightshade (Atropa belladonna)
are poisonous to people but European rabbits eat them safely. The rabbits have an enzyme, atropinesterase, that inactivates the nightshade toxin called atropine. Some fruit hang on for awhile until animals get desperate enough to eat them, or maybe because the fruit have to "age" or migrating birds arrive later to eat them. Your observation that the fruit are withering and would presumably drop might give mice and other small animals a chance to eat them. There is a hypothesis that there are many plants whose preferred seed dispersers went extinct relatively recently. The so-called megabeasts, such as mastodons, giant ground sloths, and ancestors of camels and hippos, were all killed off in America about 13,000 years ago. Some ecologists believe many trees coevolved with megabeasts and therefore have fruit or thorns that are anachronistic. Examples include the large orange-like fruit of Osage orange (Maclura pomifera) and the honeylocust (Gleditsia triacanthos) with large thorns on its trunk and large pods with seeds that have very hard seed coats. Supposedly, mastodons may have eaten such fruit. The thorns would have protected the bark. More recently in North America, Carolina parakeet and the massive flocks of passenger pigeons became extinct. They both probably left a void in seed dispersal of native plants. Then again, people have also greatly reduced the number of native plants. References Why are some fruits poisonous?: http://www.cnf.ca/naturecanada/autumn00/nc_f00_qa5.html Barlow, Connie. 2001. Ghost Stories from the Ice Age. Natural History 110(9):62-67 (Sept.) "The Ghosts of Evolution: Nonsensical Fruit, Missing Partners, and Other Ecological Anachronisms" by Connie Barlow: http://btobsearch.barnesandnoble.com...uthorInterview Maclura pomifera (osage orange) dispersal: http://groups.google.com/groups?hl=e...ing.google.com (DSmith) wrote in message . com... Last week, my wife and I were walking through the eastern Iowa woods and noticed a few small trees with lustrous red berries. They were beginning to wither, and most of the other deciduous trees had dropped their leaves. This got me to thinking: What function do the poisonous berries serve? I would assume there's some animal that can digest them and disseminate the seed, but then why were the berries withering on the vine? Is this a sign of a missing bird species (e.g., a bird species fallen prey to the West Nile virus)? Against that idea, I seem to recall often seeing such bushes full of untouched fruit. What gives? Thanks in advance, A nonbotanist dilettante |
#7
|
|||
|
|||
poisonous seed dissemination?
In article ,
(David Hershey) wrote: [snip] More recently in North America, Carolina parakeet and the massive flocks of passenger pigeons became extinct. They both probably left a void in seed dispersal of native plants. Then again, people have also greatly reduced the number of native plants. Then again again, people have also taken on a role as dispersers of seeds -- hence the spread of "weeds" around the world. ;-) Cheers, Phred. -- LID |
#8
|
|||
|
|||
poisonous seed dissemination?
The pulp around the hard seeds in Gleditsia fruits is sweet. Humans
can eat it, and many small mammals enjoy it. We have quite a few honey locusts around here, and it's unusual to find fallen fruits that have been on the ground very long. I think the critters tear them open to get at the pulp. (In fact, when we are leading field trips, if the Monday section finds a fruit, we pick it up and pin it to the tree by its own thorns, so the Tuesday through Thursday sections can see it too!) M. Reed College Station, Texas David Hershey wrote: ecologists believe many trees coevolved with megabeasts and therefore have fruit or thorns that are anachronistic. Examples include the large orange-like fruit of Osage orange (Maclura pomifera) and the honeylocust (Gleditsia triacanthos) with large thorns on its trunk and large pods with seeds that have very hard seed coats. Supposedly, mastodons may have eaten such fruit. The thorns would have protected the bark. |
#9
|
|||
|
|||
poisonous seed dissemination?
Compared to what passes for blue in animal husbandry the blue in Callicarpa
is a pretty clear blue :-) A quick try for "drupe" and "blue" in a search engine turned up quite a few hits, each in a separate family. On the other hand "blue" and "berry" was a non-starter. PvR Monique Reed schreef Our Callicarpa berries are anything but blue. They're a particularly vivid shade of screaming pinkish-purple, a color not found elsewhere in nature, I think, except in orchids and some tropical fish. Monique P van Rijckevorsel wrote: Callicarpa does not have berries, but drupes. I am wondering if the blue color is somehow connected with this. Prunes also tend to be blue and also are drupes. Just idly wondering. PvR |
#10
|
|||
|
|||
poisonous seed dissemination?
Farkleberries (Vaccinium arboreum) don't count as blue? If Callicarpa
counts, those should. Monique P van Rijckevorsel wrote: Compared to what passes for blue in animal husbandry the blue in Callicarpa is a pretty clear blue :-) A quick try for "drupe" and "blue" in a search engine turned up quite a few hits, each in a separate family. On the other hand "blue" and "berry" was a non-starter. |
#11
|
|||
|
|||
poisonous seed dissemination?
I am not claiming anything, just noting that I see something that looks like
a pattern and trying to test if it has substance ... FWIW all websites treating farkleberry seem to describe the berries as black, eg http://www.floridata.com/ref/V/vacc_arb.cfm PvR ============= Monique Reed schreef Farkleberries (Vaccinium arboreum) don't count as blue? If Callicarpa counts, those should. Monique ============= P van Rijckevorsel wrote: Compared to what passes for blue in animal husbandry the blue in Callicarpa is a pretty clear blue :-) A quick try for "drupe" and "blue" in a search engine turned up quite a few hits, each in a separate family. On the other hand "blue" and "berry" was a non-starter. |
#12
|
|||
|
|||
poisonous seed dissemination?
In the Washington D.C. area I often see honey locust pods on the
ground for a long time and have gathered supermarket bags full of pods. Perhaps you have more wildlife or trees with sweeter pods. At one time they held a contest to find trees with pods of the highest sugar content. I didn't mean to imply that honey locust was dispersed only by mastodons. Fruits or seeds of a particular species are often eaten by a wide variety of animals. David R. Hershey Monique Reed wrote in message ... The pulp around the hard seeds in Gleditsia fruits is sweet. Humans can eat it, and many small mammals enjoy it. We have quite a few honey locusts around here, and it's unusual to find fallen fruits that have been on the ground very long. I think the critters tear them open to get at the pulp. (In fact, when we are leading field trips, if the Monday section finds a fruit, we pick it up and pin it to the tree by its own thorns, so the Tuesday through Thursday sections can see it too!) M. Reed College Station, Texas David Hershey wrote: ecologists believe many trees coevolved with megabeasts and therefore have fruit or thorns that are anachronistic. Examples include the large orange-like fruit of Osage orange (Maclura pomifera) and the honeylocust (Gleditsia triacanthos) with large thorns on its trunk and large pods with seeds that have very hard seed coats. Supposedly, mastodons may have eaten such fruit. The thorns would have protected the bark. |
#13
|
|||
|
|||
poisonous seed dissemination?
Donald Wyman's book, "Shrubs and Vines for American Gardens" has a
list of blue-fruited vines and shrubs and lists 14 genera, 13 if you include Mahonia in Berberis. He has Callicarpa on his purple list. Of his 14 genera with blue fruited species, ten have drupes, three have berries (Berberis, Mahonia and Vaccinium) and one a capsule (Gaultheria). David R. Hershey "P van Rijckevorsel" wrote in message ... I am not claiming anything, just noting that I see something that looks like a pattern and trying to test if it has substance ... FWIW all websites treating farkleberry seem to describe the berries as black, eg http://www.floridata.com/ref/V/vacc_arb.cfm PvR ============= Monique Reed schreef Farkleberries (Vaccinium arboreum) don't count as blue? If Callicarpa counts, those should. Monique ============= P van Rijckevorsel wrote: Compared to what passes for blue in animal husbandry the blue in Callicarpa is a pretty clear blue :-) A quick try for "drupe" and "blue" in a search engine turned up quite a few hits, each in a separate family. On the other hand "blue" and "berry" was a non-starter. |
#14
|
|||
|
|||
poisonous seed dissemination?
Thank you.
My hypothesis, such as it is, is that when it comes to seed-dispersal fruits may be specialists or generalists. Berries are easy: any animal may take a bite (and this will include some seeds). Berries are generalists. On the other hand drupes must be eaten whole if the seed is to be swallowed and require an animal of a certain minimum size (related to the size of the drupe). As such they are more specialized than berries. The hypothesis further supposes that as a color for signalling ripeness the typical color of berries (green-red-black) are general signals to all comers, especially red. Drupes being more specialistic would tend to use other colors (blue, purple) to put out a more directional signal, ie limited to their special partners. As with all such things this may not apply in a single form across all continents and climates, but first appearences hint that there may be something in it? PvR ============== David Hershey schreef Donald Wyman's book, "Shrubs and Vines for American Gardens" has a list of blue-fruited vines and shrubs and lists 14 genera, 13 if you include Mahonia in Berberis. He has Callicarpa on his purple list. Of his 14 genera with blue fruited species, ten have drupes, three have berries (Berberis, Mahonia and Vaccinium) and one a capsule (Gaultheria). David R. Hershey "P van Rijckevorsel" wrote I am not claiming anything, just noting that I see something that looks like a pattern and trying to test if it has substance ... FWIW all websites treating farkleberry seem to describe the berries as black, eg http://www.floridata.com/ref/V/vacc_arb.cfm PvR .. |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Elaeagnus - are the berries poisonous? | United Kingdom | |||
Too much fertilizer makes vegetables poisonous? | Edible Gardening | |||
Oleander - How Poisonous? | Gardening | |||
Are any of these poisonous? | Plant Science | |||
Delphiniums poisonous ? | United Kingdom |