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

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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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108 views

Viruses selected by evolution

First let me apologize in advance for I know almost nothing about biology. I had a conversation today with a family member who is a bio-computer-scientist and he talked to me about what his colleagues ...
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Are these birch or aspen trees?

I was just wondering if anybody could help me identify the trees in this image? I am confused as to whether they are aspen or birch, a mix of the two, or whether the brown/reddish trees are some other ...
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145 views

What are those huge plants / fungi on trees called?

I've seen them in Scotland in August 2015: The plants / fungi were quite high (over 2m) on the tree. They are almost circular if you view them from the top, I guess (except for the part where they ...
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107 views

Receptors for red and far-red light in plants: Shade avoidance

Franklin (2009) describes how plants use the ratio of the red wavelength (660-670nm) over the far-red wavelength (725-735nm) (R:FR) in order to avoid shading. My question is: which receptor is ...
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270 views

How do plants intake minerals through their leaves?

How do plants intake the fertilizer when it is sprayed all over the leaf surface as a foliar feed?
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398 views

How do plants get their O₂ for respiration during the night?

If I am not mistaken the stomata are closed during the night. As a result I have a hard time to imagine how the plant can get the O2 it needs for respiration during the night. I thought the plant ...
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258 views

What's a good reference for choosing histological staining chemicals?

It's often difficult to find the appropriate or best stain to use when I want to examine a new type of tissue. I think that's partly because many histological techniques were developed a long time ago,...
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Which will produce more oxygen? Less number of (larger) trees or more number of (smaller) plants?

In a given area A, we have two choices - (i) we can plant maximum number of trees (which are larger in size) possible in A, say m OR (ii) we can plant maximum number of plants (which are smaller in ...
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109 views

Why doesn't Fenoxaprop-P-ethyl damage cool season lawns?

For controlling bermudagrass, Cynodon dactylon, a serious perennial grassy lawn weed in my area, I use the herbicide Fenoxaprop-P-ethyl. It kills the bermudagrass rather well, without damaging the ...
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171 views

How does MSMA kill crabgrass with only minimal damage to lawn grasses?

I use MSMA (Monosodium methyl arsenate) to kill crabgrass in lawns. I am not certain of the mode of action. How does this chemical work? How does it target the annual grassy weeds, without ...
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909 views

Why does wood become darker when it ages?

I have lots of pieces of pine furniture which have different colours depending on how old they are. So, I just wondered why that is. I guess it has something to do with structures and chemical ...
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86 views

Shade-loving Plants

In shade-loving plants, the light compensation point is reached at low irradiance because: A. Leaves have more chlorophyll per reaction center B. These plants have greatly reduced respiration rates ...
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73 views

Is there a model perennial plant species?

Most of plant science is conducted on small annual species with short life cycles; predominantly Arabidopsis thaliana, but also a handful of others like Oryza sativa and Medicago truncatula etc. Is ...
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Regulation in plants bearing cleistogamous and chasmogamous flowers

In most plants bearing cleistogamous flowers, chasmogamous flowers are also borne by the plants. For example, Viola, Oxalis and Commelina contain both these kinds of flowers.( I am unaware of a ...
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110 views

What controls leaf senescence in deciduous tree species, and how can I predict it?

If I want to predict litterfall, what data do I need to collect, and what statistical model might I use? For example, I might use the following coding to record phenological stage every other day, or ...
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69 views

What is this - nest, eggs, fungus?

Anyone know what these are? I found them in our local park today attached to a wooden earth-retaining wall.I was thinking some kind of insect nest/egg sac (spider?) They're about the size of a medium ...
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372 views

What flowering green plant is this?

I got this green plant as a gift many years ago, but I have never seen it flower before. It has a strong, pleasant scent and cool flowers so I'd really would like to know what it is.
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589 views

What is this Tree?

What is this plant? Location: Bangalore, India
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412 views

Why are there ecosystems?

Why would things self-organize in such a manner? I'm a mathematician and I have no baggage in ecology or biology. If the question is too broad maybe someone can point me to formal sources where this ...
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If oxygen is such a good energy source, why do plants release it?

Why do plants release excess oxygen, rather than consuming it entirely given it is an excellent energy source?
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354 views

What determines the autumn leaf color?

It is autumn out there. Green, brown, red, yellow, and mixed-colored leaves drop from the trees to the ground. What determines the colors of the leaves? Wikipedia tells me Leaf senescence is the ...
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646 views

Why are there no tree-like plants that grow in lakes?

Looking at aerial photos of boreal forests, with dense woods clear-cut by quiet lakes, I wondered why exactly are the woods so clear-cut at the edge of water? Why won't trees develop adaptations that ...
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87 views

What is this tiny thing on the branch

I noticed a tiny spot with weird shape on the shoot of a plant (Variegata), and there are many others on other branches. I wonder what is it, this is a cropped picture of it, Thank you!
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123 views

What could cause spiral tree growth?

While hiking through one of the areas burned in the 1988 Yellowstone fires, I noticed that some of the trees appeared to have grown in spiral patterns. Most downed trees have crack patterns that ...
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80 views

Identify the plant

Can anyone tell me which plant or flower is this. I have found it in Darjeeling, West Bengal, India.
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53 views

What is this species of tree?

In my city, there is a unique tree, with thorns all over it. I would like to know - what species is this?
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115 views

What is the name of this flower?

A flower has grown on a leaf in our garden. What is the name of this flower? Give some description.
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261 views

What is the trigger of pollen tube formation when the pollen is on the stigma?

What is the mechanism of pollen tube formation when the pollen is close to the stigma ? Is it because of chemotaxis? In other words, is the growth triggered by some chemical substance that is ...
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292 views

If higher levels of atmospheric oxygen can lead to larger animals, can it also lead to larger plants?

According to some information, in the ancient past (at least some) animals grew larger due to a higher levels of oxygen in the atmosphere. So for example there is this study regarding dragonflies. ...
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161 views

Can you tell the sex of a white willow when it's not flowering?

Can you tell whether a salix alba tree will produce male flowers or female flowers by looking at it, touching it or generally using your unaided senses? If not, is there any way to do that without ...
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136 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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361 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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312 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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496 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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Difference between thylakoids and lamellae in a chloroplast?

I'm slightly confused as to the difference between thylakoids and lamellae. My understanding was that thylakoids are 'discs' that are stacked into grana and there is a membrane between the grana ...
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134 views

What happens if we continuously stimulate a mimosa plant?

I know there is some mechanism in humans by which we start to ignore a certain stimuli if it persists for a long time (e.g., we don't feel our shoes all the time !). Can the same thing happen in ...
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103 views

Photosynthesis regulation

I read about the regulation of Calvin cycle by thioredoxin which activates key enzymes essentially by converting disulphide linkages on inactive enzymes into sulfhydryls. Another regulatory mechanism ...
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Does cooking or ripening reduce the concentration of solanine in nightshade?

I recall a story from one of my Botany professors where he encountered a woman picking Solanum dulcamara (nightshade) berries. When he asked her what she was doing with them, she responded that her ...
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If the haploid prothallium of a fern fertilizes itself into a diploid sporophyte, does this make all ferns clones?

From what I understand in the alternation of generations in ferns, mature spores germinate into a haploid prothallium. But how does this gametophyte produce recombinant gametes if it itself develops ...
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68 views

Total dark deprivation at day-neutral plants

First of all, I am not a biologist. Almost for a week, a question has come to my mind: "Is it harmful ceaselessly exposing a plant to light?" (I mean with natural & artificial light with ...
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441 views

Measuring algae growth or death

My daughter (10th grade) is doing a science fair project on the toxicity of triclosan for the algae Selenastrum capricornutum. She is wondering the best way to measure the effect, given the limited ...
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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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How do individual plants adapt to changes in temperature?

If you grow a plant from seed in your nice warm house, then plant it out in your temperate garden, it will stop growing for a while, possibly die, and if not, subsequently resume growth. Standard ...
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615 views

Why do apples taste sweeter at the bottom?

Sometimes when eating an apple, I notice that the bottom (blossom) end of the apple has a lot more sweetness and flavour to it, whereas the top half (stem) is often more watery, crispier and feels ...
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81 views

Why are some plants frost tender?

Why do some plants have the ability to stand frost, while others can't? Does it have to do with the size of the water vacuoles in the plant cells?
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93 views

What is the purpose of THC for a Cannabis plant?

Why does a Cannabis plant produce THC? This question is brought up drawing an analogy to nicotine in tobacco, where nicotine is developed by tobacco plants as a pesticide. Is THC a pesticide as well? ...
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353 views

Are there ways to speed up the growth of plants?

I'm interested in what humans can do to speed up the rate of growth in a plant. I'm interested in both the context of home gardening and large-scale, institution-backed projects. Obviously, optimal ...
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110 views

How are Raunkiær's plant life forms viewed today?

At the beginning of the 20th century, Raunkiær proposed a typology of plant life-forms based on where they bear their buds, roughly as: cryptophytes: belowground hemicryptophytes: at the surface ...
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What type of tree is this?

I photographed this group of trees a couple of years ago at the northern tip of Prudence Island in Narragansett Bay. Any idea what species these are?