Trees For Urban Environment #1-Morpankhi

Careful selection of trees, for afforestation drives or home gardens is missing. We usually plant trees which require least maintenance and grow quickly but never think about its eco impacts. Some trees suck up ground water making other plants wither, some make soil toxic killing all other species and some have negligible pollutant removal properties like eucalyptus, pine, palms etc. . There are plenty of research material available which compares the characteristics of trees for our type of climate.   These are mostly done by tier two and three research institutes  and hence don’t find many readers. There are research papers comparing pollution removal capacity of trees for a city or fine dust removal capacity near mining areas. Some of the research is about phytoremediation properties for removal of toxic materials from air/soil/water. We still stick to some 5-10 house plants “NASA” fame without reading that paper , which anyway is not what all plant sellers profess. You can read all about it here. We will take up all these important researches one by one .

The first  plant which is my favourite since childhood is  Morpankhi  a common bush also known as mayurpankhi belonging to the cypress family. An evergreen tree it is in leaf all year. There are two varieties of Morphankhi –Thuja Occidentalis and Thuja Orientalis . The first one is native to North America and the latter to Asia. Both are seen growing well in our subcontinent.

The first one grows in colder climates like hilly region, most probably brought and planted by colonizers. They have very little difference in leave structure but cones are different. In the images below Thuja Occidentalis  size, leaf, and cone strucutres can be seen .  Thuja Occidentalis grows to a height of 16-20 feet but Thuja Orientalis is short and more of conical structure and has been used as a potted living Christmas tree for ages in India. May be because we don’t believe in cutting trees and knew the healing properties of Thuja .

In discussions we put both the varieties as same because of similar properties.

Thuja Occidentalis  is used as pollution indicator plant as its leaves turn yellow with increase in SO2 in the environment.  [Intervenial regions of leaf turn yellow (chlorosis) or brown (necrosis)]

Here is a a photo of a  hundred year old Morphankhi (Thuja Occidentalis) three years apart and you can see how the SO2 content has changed in the atmosphere of this hilly city in India.]

Thuja orientalis is found to be  the best accumulator plant for Fe as a  soil phytoremediation.

For removal of particulate 2.5 PM2.5 matter from our air an extensive study of urban plants globally puts Thuja O at 4th place in the list of 50 such plants. It scores on all points of ranking method and has no VOC emissions. Its thin small divided leafy structure presents a large surface area for PM2.5 collection.

The leaves  contain rhodoxanthin, amentoflavone, quercetin, myricetin, carotene, xanthophyll and ascorbic acid. The leaves are antibacterial, antipyretic, antitussive, astringent, diuretic, emmenagogue, emollient, expectorant, febrifuge, haemostatic, refrigerant and stomachic. The leaves and the cones are highly aromatic and are recommended in various aromatherapies. Sap of the green cones is used as a sedative for cough and cold in hills. Boiled in water these cones provide blood circulation enhancer, stimulator and treatment of haemorrhoids. Giant squirrels feast on the dried cones. Its oils are mosquito repellents. Many villagers squash and rub the seeds on their skin to keep away mosquitoes. It’s also used in spa treatments. Homeopathy uses tincture made from its leaves(thuja occidentalis) in skin and hair care.

Thuja Occidentalis and Thuja Orientalis  Tree Flowers respectively .(second image from pixabay)

Tibetans believe that the smoke of dry cypress leaves summons holy sprits and use it in their chants. Western countries plant it in cemeteries as it’s considered the plant of the ‘God of Death’. Frankly when traditions and believes match there must be a logical reason and in this case my soul gets recharged by its smell only.

Cypress trees can be potted and made a houseplant too. Cypress trees help to moisturize the air and contribute to keeping it clean. They also release up to one liter of water a day which greatly increases humidity in the air. Much needed for dry winter days.

One of the best things about this particular tree that I like is that it grows very fast and needs very little maintenance. Grazing animals don’t damage it making it very popular for tree plantation campaigns. Being a very adapting plant it grows well in pots as well as on soil. It is sometimes used to form hedges, as it tolerates pruning.

It is found abundantly in hilly regions in India and grows well in cold weather  but I found it growing nicely in warm humid climate on the beaches of Goa  (see photo). May be GOD decided to spread its benefits to the coastal people too. What’s stopping us to revert back to this green Christmas tree.