The study of plant life; e.g. angiosperms, gymnosperms, bryophytes, pteridophytes, and algae.

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What is this Tree?

What is this plant? Location: Bangalore, India
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Evolution theory - roses spikes - being more bulgy doesn't give you advantage

I've seen spike, huge spike. And I thought that development of such spikes could be contrary to the evolution theory. Being „little more” spiky doesn’t give you any advantage... So those ...
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38 views

Can plants grow under extreme (>1%) carbon dioxide concentrations?

Related to but distinct from this question due to the concentrations involved. While small carbon dioxide concentration increases can positively impact plant growth under some circumstances and at ...
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1k views

How does a pine cone open?

When a pine cone is wet, it remains closed. However, when it's dry it opens again. From the perspective of physics or biomechanics, what is the mechanism that allows a pine cone to open and close as ...
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279 views

Sporophyte and gametophyte

My textbook says that in both groups of seedless plants (vascular plants, non-vascular plants) the gametophyte is a free-living plant, independent of the sporophyte. I don't understand this statement ...
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160 views

Is it possible to grow any kind of plant soilless (hydroponics)?

Hydroponics is a subset of hydroculture and is a method of growing plants using mineral nutrient solutions, in water, without soil. [wikipedia] My question is if is it possible to grow any kind of ...
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113 views

Is a Ginkgo tree a conifer?

I know Ginkgo is a gymnosperm, but I was wondering whether Ginkgo is also technically a conifer. I did a Google search, and found several confident authoritative-sounding answers. Unfortunately, those ...
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70 views

What is the name of this plant with many purple blooms with orange inner parts?

I have photographed the following plant in Pittsburgh, PA. It has many blooms and every bloom is very small (about 5mm diameter), purple on the outer and orange in the inner. You can see it here: ...
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77 views

How much cost would artificial pollination add to common products (fruits etc.)?

I've read about ecosystem services and their possible valuation - statements like "honeybee pollination service in the US is worth 1.6 billion dollars". Is data available on how this would affect the ...
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142 views

What is the name of this plant?

This plant was found growing in Germany. I have never seen it before, reverse Google image search did not help either. Can you help me identify what type of plant this is? Thanks, looks like it ...
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132 views

Why are neutral [sterile] female flowers present in inflorescences when they are reproductively incompatible?

In many compound and special inflorescences like spadix and hypanthodium there are sterile female flowers along with male and female fertile flowers and are often present in between male and female ...
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304 views

Why is the floral biodiversity of grazed grassland higher than that of mown grassland?

I have collected some data to compare the biodiversity of a field in which the plagioclimax is maintained by machine mowing with a field in which the plagioclimax is maintained by sheep grazing. What ...
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2k views

Online course on Plant Taxonomy and Physiology

After following a course in Permaculture, I realised that if I want to get serious about it, I need to be able to distinguish plants. So I am looking for an online Video course on Plant Taxonomy and ...
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371 views

What is the largest perennial herbaceous plant?

What is the largest perennial herbaceous plant? My guess would be some kind of banana or bamboo.
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216 views

Sexual Differentiation in Monoecious plants with unisexual flowers

In monoecious plants having unisexual flowers (eg Zea Mays, Ricinus Communis etc), there must be some mechanism as to produce two sexually distinct flowers from the same genotype. Since both the type ...
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167 views

Function of papain in papaya

I know that papain is a proteolytic enzyme present in papaya. It is often used to tenderise meat. What is the function of papain in papaya? Is papain sweet? Does it function as an antibiotic?
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2k views

Does photosynthesis require only direct sunlight

I have learned throughout my basic science classes in high school that in the process of photosynthesis, plants absorb sunlight & produce food. They use carbon dioxide & water vapour. My ...
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168 views

Plant identification?

Can anyone identify the plant below? It's in a backyard in Pennsylvania, and the photo was taken today.
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What factors affect the rate of transpiration in plant leaves?

I'm trying to get my head around factors which affect transpiration in leaves. For example, how would applying petroleum jelly to the surface of plant leaves affect their rate of transpiration? I ...
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32 views

Why do plants produce so many hybrids as a kingdom?

Why do plants produce so many hybrids? I have read that they are the largest kingdom of organisms to do so. Does this have something to do with polyploidy events?
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94 views

How does Pothos grow in only water?

The popular potted plant, Pothos aureus (or Epipremnum aureum) is happy to grow in a jar, with only water, for years. How is this possible when other plants need at least Nitrogen, Phosphorus and ...
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82 views

H₂S as a source of electrons for plants

The first electron source for plants was H2S, but now most modern plants use H2O as an electron source. What is the advantage of using H2O instead of H2S?
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How does trees know to balance themselves so that they never fall down [duplicate]

Well i was flying kites today I saw a tree and its branches were spread around in random directions... I would like to know that how do these trees know to nourish their branches in some direction so ...
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123 views

Why are there no trees in Texas?

In Texas, there is lot of grassland and many cotton fields, which need a great deal of water. However, I have not seen any forests or areas with many trees. Why are there no forests or heavily-treed ...
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351 views

Why are there so many medicinal plants?

Here is wikipedia page containing a list of plants used in herbal medicine. One might first want to argue that many of them actually do not have any medicinal/beneficial effect on heatlth. I think we ...
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What virus transforms full grown plants?

I read an article by a gardener describing how a virus had transmitted a negative trait to his plants. It rather shocked me, because I hadn't realized that a virus could transform an adult plant. I ...
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457 views

Family tree for edible plants?

I am looking for a family tree for plants, particularly veg / herbs / fruit. Something similar to: If it could be slightly less technical than all the Latin ...
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38 views

What are the mechanistics of stinging nettles?

There is a lot of research on why nettle extracts causes skin irritation and a stinging sensation. However, I cannot find information on how the extract is injected in human skin. Similarly, I haven't ...
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561 views

What is the name of this flower with purple leaves and orange inner part in NYC?

I've photographed this flower a few days ago in New York City: Does anybody know the name of it? (and how is the orange part called?)
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509 views

What kind of tree could this be?

This may be a strange question, but does anyone know what kind of tree this could be? I know, it's just a comic, but these trees, at “walking distance” within that comic are easily identifiable as ...
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84 views

What chemical or biochemical agents do plants use to inhibit each other's growth?

As I just learned, allelopathy is the action by which plants regulate the growth of other nearby plants. I have hear of ethylene is a general signal for growth and fruit ripening in particular, but ...
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103 views

How common is bacterial mediated transformation? In plants? In animal cells?

The most common method to transform plants is by soaking plant tissue in cultures of agrobacteria (this is not their current classification) which transfer DNA into the plants. Is lateral gene ...
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411 views

Why do plants' leaves become enlarged in low light areas?

Why do almost all plants in shade have a smaller stem structure and larger leaf than that same species grown in a well lit, sunny area?
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79 views

What does the empty space in the bamboo stem do?

Is the empty space inside a bamboo stem a xylem? And why is the space so large?
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167 views

What does “chlorophyll photosynthesis peak” mean in relation to photon wavelength?

When reading about how green / leafy plants work, I saw that they have chlorophyll A & B, which allow the plant to use the energy from light by capturing and transforming. When reading about ...
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234 views

Where does crop biomass come from?

Each year, large volumes of crop are harvested from fields. Where does this biomass get replenished from?
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Convergent evolution of fruits

Many fruits are not homologous, originating from different parts of a plant. Yet they all have similar properties: Ripe fruits all have yellow to dark red color They all have a lot of water and ...
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269 views

What does x in “Miscanthus × giganteus” name stand for?

I came across a species name that contains "x" in its name, namely Miscanthus × giganteus. What does this symbol stand for and is it commonly used in taxonomic nomenclature?
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104 views

What does the root “phyllum” mean used botanical binomial nomenclature

I often encounter the root "phyllum" in bionomial names in botany, but I've had trouble finding an actual definition for this root in any Latin dictionary outside of its taxonomic meaning. From ...
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149 views

Help identify this awesome climbing plant with velcro like stem

I got this plant sprouting in my window box this spring. Starting from a single seed, it has grown into an impressive array of branching climbing vines, reaching 6 feet tall. The stem turned red as it ...
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is it necessary that every theca of an angiospermic anther must contain two microsporangia

i basically don't know the procedure or sequence of steps involved in the formation of anthers but i have read it somewhere it is formed from the dedifferentiation of shoot apical meristem of the ...
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208 views

Are there any air-plants with parts that are edible for humans?

Are any air plants (Tillansia sp.) safe for humans to eat? I haven't been able to find whether or not there are. Pineapple is in the same family (Bromeliaceae), but isn't an air plant.
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58 views

What is the cause of the spots on this leaf?

On a hiking trip to the Alps I found trees whose leaves showed those spots you see on the picture. I am curious about what the cause is. Higher resolution pictures of front and back side.
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Why are there more stomatal openings on the lower surface of a dicot leaf?

This causes more transpiration to occur from lower leaf surface. What's the exact reason for why are there more stomatal openings on the lower surface of a dicot leaf?
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56 views

How much pollen is needed to pollinate a flower?

Assuming 100% of the pollen gets delivered to exactly the locations it needs to pollinate a female flower, how much pollen is needed to pollinate a flower? If it's more than one unit of pollen, what, ...
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1answer
41 views

Why are the genomes of some trees so large?

For example, the current longest known genome belongs to a tree: http://motherboard.vice.com/read/the-largest-genome-ever-sequenced-belongs-to-a-tree I have heard that this could potentially be ...
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1answer
67 views

How can a plant resist glyphosate (Roundup) herbicide?

In my area, the most common weeds that strongly resists (N-(phosphonomethyl)glycine) (glyphosate) are the horseweed, or mare's tail, Conyza canadensis, and Canada thistle, Cirsium arvense There are ...
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227 views

Where do trees get their shape?

Does anyone know any good resources dealing with shapes of trees? For example, pine trees are cone shaped for optimal absorption of sunlight, but lone pine trees growing in isolation (and other ...
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1answer
35 views

Seed Dormancy and Seed Transportation

My textbook says "As the seed matures it loses water and enter dormancy". I am confused as to whether this happens before the seeds are transported or after, and as to how seeds know to become dormant ...
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538 views

When happens when pollen grains land on the a part other than the stigma of a flower of the same species?

When happens when pollen grains land on the a part other than the stigma of a flower of the same species? Would the pollen be transported to the stigma or would it just sit where it landed and nothing ...