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56

It's a matter of perspective. Most of the chemicals that are addictive to us humans (particularly alkaloids), and may be addictive for some other animals as well, are also insecticides. Lots of plants that we consider poisonous are good food for other species, and lots of plants that insects would consider poisonous are treats for us. This is a great ...


26

As someone commented earlier, chemicals such as nicotine and morphine were products of evolution meant to repel animals. It is explained in more details in this article here. Evolutionary biologists studying plant–herbivore interactions have convincingly argued that many plant secondary metabolites, including alkaloids such as nicotine, morphine and ...


10

I am providing an example which somewhat contradicts the points mentioned in the other answers regarding toxicity of alkaloids to insects. Caffeine is a stimulant and is toxic at high doses (also for humans) but at low doses it has a stimulating pharmacological effect on the organism. The same principle applies to insects as well. A study by Wright et. al ...


6

It appears to me to be a Night Blooming Cereus: We had one in our greenhouse in Botany. It rarely bloomed, and the bloom was wilted by mid-morning. Night-blooming cereus is the common name referring to a large number of flowering ceroid cacti that bloom at night. The flowers are short lived, and some of these species, such as Selenicereus ...


6

Short answer The appearance of psychoactive compounds in plants has nothing to do with their addictiveness in man. Background Psychoactive plants were there long before humans. The question therefore should be: "Why would humans evolve brains that exhibit addictive propensity to poisonous compounds abundantly available in nature"? The answer is: because our ...


5

Excellent question! The main reason why us humans bury seeds seems to be to keep seed-eaters from finding them, though any historical evidence that could conclusively prove why we started doing that is probably lost to time, since we discovered agriculture before we began writing things down. Beyond that, you've rightly identified a number of advantages to ...


4

It is of Phytolacca genus plant which could be toxic for mammals, DO NOT eat as is - it should be cooked properly to be usable/edible (the older, the more toxic leaves are). Phytolacca acinosa:


3

I think this is a Canistel (Pouteria campechiana): The fruit are yellow when when ripe, but the form and also the leaves look very similar. The fruit are edible raw, you can find some more information here.


3

SHORT ANSWER From the air LONG ANSWER Trees are autotrophs, which means that they create their own compounds from inorganic carbon. So, carbon comes from inorganic carbon. This carbon comes from $CO_2$ (carbon dioxide) that is present in the air. The process by which this carbon is transformed into organic matter is called photosynthesis. More ...


3

Unfortunately, this is not a fossil, but a pseudofossil: a pretty deposit of iron or manganese called a dendrite.


2

Aquatic plants including algae acquire carbon from dissolved bicarbonates (HCO3-) [1,2].


2

It seems like it's either a Paeonia brownii or Paeonia californicus. According to Wikipedia, these are the only peony trees native to North America, but there aren't any that are native to Canada specifically. I guess these are the closest you can get. I added some images to hopefully help you out a bit. https://en.wikipedia.org/wiki/Paeonia_brownii ...


1

That'd be a peony tree. I'd say they're a pretty common occurrence! https://en.wikipedia.org/wiki/Peony I'm afraid I'm unfamiliar with identifying the individual species, however, if anyone is more knowledgeable here than me.


1

I think it is a weeping willow but i am not very sure.


1

The genus is Lantana, of Verbenaceae. That particular one could perhaps be L. camara. There's a number of papers that exist which study L. camara in Bangladesh, just some examples: http://link.springer.com/article/10.1007%2Fs11676-007-0060-6 http://www.banglajol.info/index.php/BJB/article/view/1513


1

The short answer is NO. A shadow is strictly due to the blocking of sunlight, so the shadow of 2 equally non-transparent (i.e., same density of leaves, both have similar trunk diameter, etc.) trees on the same hillside in the same weather conditions would not have different temperature shadows. A plant's metabolism can and will affect the temperature ...



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