If you want functional decorations, look no further than the houseplant. Some well-placed greenery can not only brighten a space but also purify the air -- and they're also helpful in creating a more relaxing, restful ambiance in any room. We know that spending time in nature is linked to reduced stress levels and tension relief. What's more, in a 2008 study, Dutch researchers found that hospital patients with indoor plants in their rooms reported lower stress levels than patients without them. That's why we've rounded up 10 beautiful houseplants that are easy to take care of and effective at increasing oxygen and clearing out toxins for cleaner breathing air, some of which even have the NASA stamp of approval. Try adding one to your bedroom or office space for a little dose of zen. What are your favorite decorative plants? Tell us in the comments below! The gel of the aloe plant has a number of healing properties. Not only does it soothe skin burns and cuts, it can also help to monitor the air quality in your home.

The plant can help clear the air of pollutants found in chemical cleaning products, and when the amount of harmful chemicals in the air becomes excessive, the plants' leaves will display brown spots. Just an FYI: It grows best with lots of sun. NASA scientists listed the English ivy as the number one best air-filtering houseplant, as it is the most effective plant when it comes to absorbing formaldehyde. It's also incredibly easy to grow and adaptable -- try it as a hanging or a floor plant. personal air purifier allergiesGrow in moderate temperatures and medium sunlight.best carpet cleaner spray pet stains Rubber trees are good for cleaning the air and are one of the easiest plants to grow, as they thrive even in dim lighting and cooler climates. air purifier singapore best

The low-maintenance plant is a powerful toxin eliminator and air purifier. Snake plants don't need much light or water to survive, so they're an easy choice for any corner of your home. The plant absorbs carbon dioxide and releases oxygen during the night (while most plants do so during the day), so add one to your bedroom for a clean-air boost. The attractive bamboo palm also made NASA's list of top clean-air plants with a purifying score of 8.4. It's also particularly effective at clearing out benzene and trichloroethylene. These need to be well-watered, in shade or indirect sunlight. The heart-shaped philodendron is a popular plant choice for indoor areas, as they're easy to care for and can grow decorative vines. Like the English ivy, they are particularly good at absorbing xylene. They can also last for many years when properly cared for. Grow with moderate water and some sunlight and they'll be fine. One of the most common house plants, spider plants are decorative, easy to grow, and also make the NASA list of the best air-purifying plants.

Spider plants are effective at fighting pollutants including benzene, formaldehyde, carbon monoxide and xylene. This beautiful, vibrant plant can grow to be ceiling-height (15-foot dracaenas are common), making it a great plant for decorating and filling up space. It also removes toxins including xylene, trichloroethylene and formaldehyde from the air. Grows best in sunlight. Huffington Best House Plants Houseplants Ficus-tree Best Indoor PlantsDo Indoor Plants Really Clean the Air? Sure, that potted fern is pretty, but can it really spruce up the air quality in your home? Studies by scientists at NASA, Pennsylvania State University, the University of Georgia and other respected institutions suggest that it can. Plants are notoriously adept at absorbing gases through pores on the surface of their leaves. It's this skill that facilitates photosynthesis, the process by which plants convert light energy and carbon dioxide into chemical energy to fuel growth. But scientists studying the air-purification capacities of indoor plants have found that plants can absorb many other gases in addition to carbon dioxide, including a long list of volatile organic compounds (VOCs).

Benzene (found in some plastics, fabrics, pesticides and cigarette smoke) and formaldehyde (found in some cosmetics, dish detergent, fabric softener and carpet cleaner)  are examples of common indoor VOCs that plants help eliminate. These VOCs and other indoor air pollutants (such as ozone) have been linked to numerous acute conditions, including asthma and nausea, as well as chronic diseases such as cancer and respiratory illnesses. An indoor plant's ability to remove these harmful compounds from the air is an example of phytoremediation, which is the use of any plant — indoors or out — to mitigate pollution in air, soil or water. Indoor plants remove pollutants from the air by absorbing these gases through their leaves and roots. The microorganisms that live in the soil of potted plants also play an instrumental role in neutralizing VOCs and other pollutants. While most leafy plants are adept at purifying indoor air, some of the plants that scientists have found most useful in removing VOCs include Japanese royal ferns, spider plants, Boston ferns, purple waffle plants, English ivy, areca palms, golden pothos, aloe vera, snake plants and peace lilies.

Follow Elizabeth Palermo on Twitter @techEpalermo. We're also on Facebook & Google+.Edit ArticleHow to Purify the Air Using Plants While an air purifier can do some of the work of making the air around you at home or work a little fresher and purer, plants can do a much better job of filtering the air than a machine, plus they do it more quietly and without using up energy from your power plant. And they are pleasant to look at and provide us with a sense of nature close to us each day. Why not give them a try to see if you can sense the benefits? Understand the importance of purifying indoor air with plant filters. Indoor air is some of the worst air we breathe on a daily basis because it is inside that everything builds up from the off-gassing of chemicals in many of our products. We are exposed to a range of indoor air contaminants daily, including, smoke, toxins, chemicals off-gassing, pesticides, detergent fumes, mold, small fibres, bacteria etc. While cleaning takes care of some of it (provided we take care what we clean with), it cannot take care of many of the air contaminants.

However, in a NASA study it was found that "houseplants can purify and revitalize air in our homes and offices, protecting us from the negative effects of such common toxins as ammonia, formaldehyde, and benzene." Understand how plants help us. Plants act as filters because they absorb the toxins through their leaves, especially those with the largest leaves. The theory is that if the plants do the absorbing first, our nose and lungs take on less of a burden. That means reduced incidence of asthma, allergies, reactions to mold and other particles, and immuno-suppressed illnesses. Decide where you have room to place plants. Think about which rooms could do with having plants purifying the air. Usually bedrooms are an excellent place for plants as they convert carbon dioxide into oxygen. Consider rooms that are heavily laden with electrical equipment, such as studies and TV rooms, and areas that have high fume potential, such as kitchens and art workshops, etc. All offices can benefit from the addition of plants.

Select your plants according to their benefits. Use larger leafed varieties where possible. Some of the best plants are considered to be a "top 10". Janet Craig dracaena - breaks down benzene, carbon monoxide and trichloroethylene English ivy - breaks down benzene and trichloroethylene Peace Lily - breaks down benzene and trichloroethylene Rubber plant - good for filtering a range of nasties, such as formaldehyde, benzene and ammonia. Consider some other great plants as well: Snake plants - these plants are amazing growers and very resilient. They are great at removing most toxins and they are happy to grow where other plants might wither and die (such as a hot windowsill, for example). They are also good bathroom and dark space plants. Christmas cactus - here is a plant that does well in rooms that are darkened in the evening, such as the DVD and game zones. Spider plant - great for removing formaldehyde, carbon monoxide Bamboo palm - another good formaldehyde remover, as well as carbon monoxide