Tag Info

Hot answers tagged

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 ...


50

The phenomenon in question is probably related to geotropism. If the hill soil is "on the move" it will cause the bend on the trees - If the soil in a slope is moving downward, the trees on this slope will tip downward. As the tree continues to try to grow upward, the trunk will show a curve. The degree of bending could indicate the rate or ...


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 ...


25

Ripening of bananas is induced by ethylene (see reference 1), which acts as a hormone and induces the ripening process. The incomplete combustion of the leaves produces ethylene, additionally the warmth of the process will help the enzymes as well. There is even a paper about this technique (although it is unfortunately not accessible), see reference 2 for ...


24

That molecule is called Geosmin. It is mainly produced 1 by Actinomycetes such as Streptomyces; filamentous bacteria that live in soil. Other organisms also produce geosmin: Cyanobacteria Certain fungi An amoeba called Vanella A liverwort It is an intracellular metabolite and cell damage is the primary reason attributed to its release. However oxidant ...


22

The use of a genus-species notation gives more exact information. For example there are multiple species of chamomile: There is Roman chamomile (Chamaemelum nobile), German chamomile (Matricaria recutita, or Chamomilla recutita) and Dyer's chamomile (Anthemis tinctora). The first two species are appraised for their medicinal properties and help to calm upset ...


20

There was a 2011 study where they used a sensitive atomic magnetometer to try to detect a plant's magnetic field. They stated that: To our knowledge, no one has yet detected the magnetic field from a plant. Biochemical processes, in the form of ionic flows and time varying ionic distributions, generate electrical currents and time-varying electric ...


19

Angiosperms -- that is, flowering plants -- only evolved relatively recently on an evolutionary timescale, about 125 millions years ago. So for most of the history of life on earth there have been no flowering plants. Thus it seems highly likely that if angiosperms were to suddenly disappear, life on earth would continue. There might be a massive disruption ...


18

Photosynthesis is nearly all visible light. There's usually not enough UV and thermodynamics more or less rules out infrared. Chris covered that pretty spectacularly, but that nearly is significant. There is some evidence that certain kinds of fungi can use gamma rays or other ionizing radiation for energy, but they're not particularly common. Melanin is ...


16

A quick google image search reveals that, indeed, Texas has quite lush forests. Remember that the state is extremely large (as compared to the Northeastern states, for example), and encompasses a huge variety of terrain, climates, rainfall amounts, etc. While the stereotypical view of Texas is rugged, dusty terrain: From: ...


15

Photosynthesis only occurs in the visible light.have a look at the absorption spectra of the different pigments involved in photosynthesis, you see that all these pigments absorb light between 400 and 700nm (from a diagram from here): You see that the absorption spectra of chlorophyll a and b are located from 400 to 500nm and again from 630 to 700nm. The ...


14

The plant is of Lamiaceae family and its common name is Shell Flower or Bells of Ireland. Its "scientific" aka latin name is Moluccella laevis.


12

The short answer: Fruits are large compared to seeds because humans have made them large. In the natural environment, there is a different set of evolutionary pressures. A fruit has to be able to successfully propagate itself using its seeds, while commercially farmed fruit is usually cloned via vegetative propagation. Therefore, the commercial farmed ...


12

I think this is the Chinese Redbud (Cercis chinensis), see this image (from here):


12

It looks like a "Spider lily" from the Hymenocallis genus. Here is a picture of Hymenocallis caribaea from wikipedia for comparison: There are however ~65 species in the genus (according to wikipedia), and I cannot say exactly what species you have.


11

They are not individual cells. In fact, the "juice sacs" (as they are known) are actually specialized, multicellular hairs: Juice sacs originate as multicellular hairs in which the interior of the enlarged distal part breaks down and fills with liquid. The juice sacs constitute the fleshy, edible pulp of an orange and are the source of the sweet juice. ...


11

It looks like the common Geranium sylvaticum (also called wood cranesbill or Mayflower), and it is at least a close relative (member of the Geranium genus). This plant is commonly found across Europe and in parts of Asia (see map below), and it is sometimes planted in gardens. It is a perennial herb that grows in many types of habitats (woods, meadows, road ...


10

Most varieties of corn bred for modern use have between 8-20 rows of kernels (Bommert et al. 2013.. Nearly all varieties have an even number of kernel rows. This is due to the early development of the ear. Ears of corn are developed from pistillate flowers on the ear (Bortiri and Hake 2007). Pistillate flowers are the female flowers, so they will bear ...


10

I have been looking into this for days, but this plant is difficult to identify without its flower. I reached out to a botanist at Dartmouth, who suggests that it is either one of two species-- a nasturtium (Tropaeoleum sp.) or a geranium (pelargonium). The leaves are what are called peltate, meaning shield-like with the stem attached directly underneath. ...


10

It looks very very suggestive for Artocarpus altilis or Breadfruit tree. Another variants - Artocarpus camansi.


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 ...


9

The Latin names are known in all countries. The "popular" names are only popular in one or maybe two languages/countries. So, learning the Latin names, enables you to communicate international more easily.


8

In my experience (in common with the experience of everyone I've talked to who could be considered an expert on the subject), taking old wood and using that as a scion when grafting new trees rejuvenates them, and they grow as new trees. I'll take apple trees as an example. As you can see from the table here, there is a distinct age after which the tree ...


8

Yes they can, but their normal growth is somewhat impaired. A study by Bugbee and collaborators showed that while the yield of rice and wheat increases with CO2 up to about 0.1% CO2, yield decreases sharply as CO2 climbs from 0.1% to 0.25%. There is a smaller loss in yield as CO2 is further increased from 0.25% to 2%. One interesting thing to note about the ...


8

As @dd3 stated, it's a spiny (or prickly) sow thistle. It's an annual common in most of the US. The leaf itself does not have a stem, and if you break the central stalk, it should be hollow and there should be a milky exudate. The plant spreads by fluffy seeds produced from a small dandelion-like flower. If you pick it while young, it won't hurt (as much); ...


8

It's a bit early yet, but it looks very much like a weed known in my area as "cleavers" or "clingweed" (Galium aparine) because of it's tiny stiff hairs which make it catch and cling to clothing. The picture below is for a fully mature plant, which is stiffer and stickier than when they first sprout. Note the whorl arrangement of (usually six) leaves, with ...


8

The tree in question belongs to the Araucariaceae family, There are multiple species of Genus Araucaria, I'd place Araucaria araucana on the first place, but there are multiple others: Araucaria araucana Araucaria luxurians Araucaria columnaris Araucaria subulata


8

It generally won't be more helpful. Not only will the names be different in different countries, there may be different types of the same species with different properties, or even different species with the same common name. If you have an allergy to something like coriander, being able to read the label and see what contains actual coriander and what ...


8

It looks very similar to Cephalaria gigantea.


7

There is no color code for the leafs - the color results from biochemical reactions. Basically there are three colors: Green, yellow and red. Green color is caused by the chlorophyll inside the chloroplasts, when the leafs are active in photosynthesis. Yellow color is caused by Carotenoids, which are present in the leafs all the time, but are masked by the ...



Only top voted, non community-wiki answers of a minimum length are eligible