When I last went grocery shopping, I purchased a bag of reduced-price fruit. Alongside the pears and a Granny Smith apple reposed a mango. So I thought...OK! Possessing a combination of zero mango experience and a vague awareness that these drupes have a growable seed within, I looked up information on how to dissect and sprout... ...and was astonished to learn that Mangifera indica is a member of the family Anacardiaceae---as are Cotinus, cashew---and poison ivy! My astonishment turned to horror when I further discovered that, like the detested Toxicodendron, mango produces urushiol---a chemical, to my sorrow, with which I am all too familiar. This blistering allergen can be found in mango peel and in the plant's leaves and bark. Allergenic urushiols are present in the fruit peel and can trigger contact dermatitis in sensitised individuals. This reaction is more likely to occur in people who have been exposed to other plants from the family Anacardiaceae, such as poison oak and poison ivy, which are widespread in the United States.[13] (Above from Mangifera indica - Wikipedia) My questions are these: 1. Should I, a proven urushiol-allergic, be anywhere near this mango? Apparently I could eat the fruit IF I could figure out how to peel it safely. (With gloves and a welder's mask, maybe.) 2. How can I perform the necessary maneuvers on the seed (cutting husk open; handling seed to sprout and plant)---and how can I grow a plant whose leaves I cannot touch without danger of blistered skin? Biding its time on a fridge shelf, the mango awaits my decision. Advice invited!
You are very humourous and I like that. Time for some tough love here though. Mangoes are not your friends; you do not need them in your life and they are not worth the trouble to peel, let alone grow. Is there a 'forbidden fruit' syndrome going on here? My husband cannot eat limes or grapefruit anymore because of interactions with certain medications he takes. Disappointing but . . . Neither you nor he are alone in having to give up things you like to eat; lots of people are prevented from eating all sorts of delicious foods such as milk, eggs, soy, wheat, tree nuts, peanuts, fish, and shellfish. I hope mangoes are the only thing that causes you problems because I'm sure you can learn to live without them. Life is full of disappointments.
That's so interesting - I have never known anyone who had a reaction to mangos, but it's clear from several websites that it happens and can be serious. Do you eat cashews or pistachios? The page at Can You Eat Mango Skin? Urushiol and Contact Dermatitis (thoughtco.com) says that "Soap and water can be used to remove traces of urushiol from skin", making it sound like you'd only need to take the kind of precautions that we're all used to taking now with possible COVID-19 exposure. I wonder if that's true enough. You could wear gloves like food handlers do when you're cutting the fruit and planting the seed. You might have to remember to always wash your hands when you come into contact with the leaves, and not brush against them with bare skin. It seems that Allergists do have tests for mango sensitivity.
But mangos are so tasty... The seed can be easily germinated without much effort. Remove as much of the pulp as possible then wrap it in a fold of moistened paper towel. Encased it between two small plates or saucers and place in a warm place. Monitor progress periodically, adding moisture and replacing the towel as necessary. Remove the towel and lay the seed flat on soil when it begins to sprout. Mango leaves do have tiny specks of sap on both top and bottom surfaces. There's none that I can see on mature bark and almost none on green stems.
Togata57, you could try a graduated series of exposures to the mango to see if you are allergic. If you have handled it already without any reaction, try cutting a small piece of mango skin and touching it to your body in an out-of-way place. If still no reaction within a day, try larger and larger pieces until you know if you react to the skin, and then do the same with eating the flesh. There is a good chance that you won't react at all, and you will find out if you actually like to eat it. I think that mangoes are very tasty, but my wife is allergic to them.
If you try that, the fruit will be rotten before the multiple day tests are completed :-) To be on the safe side, wear latex goves when cutting open the mango, and then eat the pulp with a teaspoon without touching the skin. I'd discard the seed; although fairly easy to germinate, it is a tropical tree, so not hardy outdoors, and too large for long-term indoor growing (you won't get any fruit unless you have a huge greenhouse); it also isn't particularly ornamental, just fairly 'ordinary' coarse medium-large leaves without any notable decorative character. Then on top of that, the risk the foliage might give you allergy problems.
Do you have a spouse or friend you could leave the handling to? I lived on a tropical island for 35 years and mangoes were widespread, removing the stringy flesh from my teeth was the major drawback along with the suffocating smell of rotten mangoes from untended yards.
Thanks to everyone for your thoughtful responses and sound advice. My thoughts had been trending this way. Asked myself---Is this worth all the angst? Undoubtedly, as I have been so doing for several decades! Yes, though rarely. Thought of this...but lacked the bravery to do so. Yes, I did hold the mango briefly while removing it from bag/placing in fridge...without consequences...does this brief contact qualify? Your idea is a good and sensible one. Usually I eat fruit with peel left on. WOW was I glad I did not do so in this case! Cannot even imagine (nor will I try to do so) the result of urushiol ingestion. (!!!) GAH!!! The fetid underbelly of paradise, eh?!!! Puts me right off my (imaginary) trip to the Caribbean. Seriously, wind-borne---tell us more about your sojourn. I am sure that you have tales to tell. Read enough about mango seed germination and plant growth to see pix of this phenomenon---gotta agree with you there, Michael F. ---Why do mango plants do this? Again, my thanks to everyone. Plants...mysterious little creatures, aren't they?
The theory I've seen cited is that wilty leaves look unappetizing to herbivores, so they are more likely to leave the otherwise-undefended tender new leaves alone. It is quite a common phenomenon in tropical / subtropical evergreens; Lychee also does it for an example.
Perhaps the wilt has something to do with the internal hydraulics of the mango: The mango has developed a unique method to deal with periods of flooding. In cases of high water, the mango tree produces swollen lenticels on the trunk above the waterline. These nodes help in removing toxic byproducts produced when the plant is forced to undergo anaerobic metabolism. Above from : Mangifera indica The ability of mango trees to survive prolonged flooding, as presumably often occurs during heavy monsoonal rains, appears to be dependent on the development of hypertrophic (swollen) stem lenticels Above from paragraph 1 page 3 of : http://www.avocadosource.com/Journals/HortScience/HortSci_2006_41_3_PG_549-555.pdf Does periodic wilt pertain to regulation of water content? Plant feels dehydrated or bloated, takes a time-out to let things get sorted? Maybe to work on putting the sap in Sapindales? Plants have their reasons that reason knows nothing of. (Apologies to Pascal.)
The young leaves remain limp and tender until they have reached their adult size at which point they gradually increase their thickness and become distended while losing their juvenile pigment. The leaves start off being red, becoming a sandy-tan color before finally becoming green in adulthood. Aside from what has already been suggested, perhaps they remain limp in order to minimize the surface area exposed to potential damage from animals and from the elements and to minimize the loss of moisture. Also, since they lack the chlorophyll to carry out significant photosynthetic activity there is no need to extend the leaves when they are young. So goes my conjecture.
I have not ever allowed the soil to dry to the point of stressing the tree so I've not seen the wilting of adult leaves. Here is a photo of my tree with young leaves along with a few adult ones: Appreciation: - Rejuvenated mango tree.
So, the age of the leaf is the operative factor on plants of any age. How new are the leaves shown on your plant? From pruning to this pic, how much time elapsed? And another thing: how long does it take for the leaves to 'un-wilt'? Hope that your handsome tree continues to thrive.
A similar limp new leaves thing happens with Lithocarpus cleistocarpus: (3) July 11, 2012 - some great leaves, and lots of flowers too | UBC Botanical Garden Forums and Neolitsea, though the new leaves on that are covered with dense hairs on both sides, so they appear more plump yet still droopy (and so soft and silky!). Here is Neolitsea sericea: Neolitsea sericea.
Does it ever occur in non-tropical plants? Fortunate herbivores that can munch urushiol-laden leaves with impunity! (Immunity, even.) I have read where many/most animals are not bothered by poison ivy...another mystery to solve. Why aren't they?---and, if explanation can be found, can this immunity be granted to humans? Surely there is a scientific term for this wilting phenomenon. ---Or is there? Little did I know that the mango is a fruit of such intriguing mystery! The more I learn, the more I realize how much I don't know. ---Albert Einstein
I don't remember exactly but since the post was made in early January 2021, my guess would be it was pruned sometime around October 2020. It would likely take that long to develop new growth given the limited amount of light during that time of year. All changes are so gradual that it's hard to say how long the complete process takes. Sorry, my bad for not keeping records. The first growth is extremely thin and delicate, so much so that I resist touching it for fear of damaging it. I find this plant much more interesting than an all green Dracaena, not to mention the wonderful smell of mango when one breaks open a leaf. Its large size is its drawback as a houseplant. I'll probably have to prune it again this year.
For the sake of comparison, I have updated the 'rejuvenation' thread with a current photo of my tree.
Not sure how far extra-tropical it goes; see Wendy's link to Lithocarpus pics though. I guess arboreal herbivores are rarer in temperate habitats, so less of a risk. I've read the same for Native Americans and Asians who have lived alongside urushiol-containing plants for generations and evolved some immunity. It's just people of European descent who haven't met urushiol-containing plants before who get hammered. Barrie Juniper (Int. Dendrol. Soc. Yearbook 1993: 49-57) calls them 'flamboyant flushes'.
It doesn't even take generations to evolve immunity to Urushiol. As a child, I was very susceptible to rashes from contacting poison ivy plants. However, apparently because I developed these rashes every year for many years, by the time I was in my late teens, I had developed complete immunity.
