What you see on the left are a stand of what we call soil orchids, some of which have been beaten to the ground by heavy rains, and on the right a stand of robust Curcuma (locally, resurrection plant) leaves. The orchids have been straining toward the light for some time – we had no idea the Curcuma would cast so much shade when we planted it there – and the rains just helped them plunge on down to the ground.
The orchid stems can grow to 3 meters tall, and the flowers are at the very top, so their gradual leaning over the past week or so gave me the chance to take some images of the lovely flowers.
Panama is home to no doubt hundreds of species of native orchids, and Potrerillos has a particularly fine climate for them, but the first orchid I decide to write about, this one, was introduced from Asia! My excuse is that this orchid is highly conspicuous, being very popular as a cultivated plant. It’s been introduced to Puerto Rico, Costa Rica, Guatemala, and Panama, according to wikipedia, for this purpose. I had to wonder what the chances were that it would become an invasive plant.
If you don’t live in our neighborhood, and you’ve seen these orchids, you may very well know them as “bamboo orchids.” They are reminiscent of bamboo, with their reedy stems, formation of large clumps, and fairly tall size. Their scientific name is Arundina gramnifolia.
- Arundina comes from the Latin arundo, meaning reed,
- and gramnifolia means grass-like leaves (botanary).
So let’s take a closer look at these reedy stems and grass-like leaves.
If you saw this plant without its obviously-orchid flowers, how would you know it was not a bamboo or some other member of the grass family?
- The leaves are long and narrow – like grasses
- The leaves have sheaths that clasp the stem – like grasses
There are, actually, quite a few differences in the leaf structure between the orchid and the grasses if you look closely, but the easiest way to tell this plant is not a grass is by checking its stem.
- Grass stems are hollow.
- This stem is quite solid.
By vegetation alone, then, we can see that it is not a grass. It’s the flowers that tell us it is an orchid.
Arundina flowers
Even though we usually see only one flower at a time at the tip of a tall stem, the flowers occur in clusters, though of not more than 10. You can see the buds for new flowers here.
Arundina flowers, like all orchid flowers, have an outer whorl of 3 sepals and an inner whorl of 3 petals. The petals and sepals generally look so much alike that in the orchid world both sepals and petals are called tepals.
In the images below the flower is face down. The sepals are labeled in the left image and have been removed in the right image. (Click on either image for a larger view.)
When you remove the 3 sepals, you are left with 3 petals, but it looks like 2 petals plus another flower! This is a characteristic orchid structure. The middle petal is called the labellum, or lip, and it is always different from the others and larger than the others. It ends up at the bottom of the flower and provides a platform for orchid pollinators (wikipedia).
The next two images show (at left) the petals turned over so you can see the labellum and (at right) the labellum opened up so you can see the yellow-streaked platform highway for the pollinators. (Click on either image for a larger view.)
Okay, then what is that phallic-shaped space module in the middle of the labellum? Oddly enough, it’s, to oversimplify a bit, the male reproductive part of this orchid – the column that carries the packages of pollen, the pollinia, discussed recently here. Without consulting an expert, I’m certainly not going to try to label the parts of this incredible structure, but I think the pollinia are stored in the little cap-bill of the column pointed to by the arrow.
At least, when I touched that part of the column with my finger-tip, it fell off fairly easily. If the pollinator has followed that yellow streak pathway up toward the column, it wouldn’t take too much effort for that cap-bill to detach from the orchid and attach to the pollinator, in my viewpoint, anyway.
So, what pollinates Arundina, and what does the pollinator get in return?
From a study in Puerto Rico, where Arundina graminifolia has become naturalized, and also from Zuchowski in Costa Rica, I would expect bees to be the pollinators here in Panama. However, at the time I was taking pictures, anyway, I saw only ants, some other tiny unidentified insects, and this lightning-bug type guy.
I wasn’t sure the bug was serious, but pretty soon, I saw this:
There he is, traipsing right up the pollinator highway. And what will he get for his efforts? Well, no nectar, that’s for sure. Arundina is what is known as a “rewardless” orchid. Perhaps in this case, fair is fair, because it’s hard for me to see how those pollinia would find a surface on this insect’s body, anyway.
Is Arundina gramnifolia invasive here?
Getting back to that original, idle question – it turns out that this “rewardless-ness” is one of the reasons this exotic plant from Asia may never become an invasive species here in Central America. Studies in Puerto Rico showed that although Arundina graminifolia had become naturalized there, the infrequency of pollinator visits (no nectar reward, why visit?) meant infrequent fruiting and therefore the orchid spreads in its new environment at a rate similar to native species.
Guilt-free exotic plant gardening!
Hi, A lovely, attractive orchid for the garden. You explained so well its merits, how it grows etc. I grow some Orchids, easy ones! like Dendrobiums. I have also a very tall Vanda growing up a tree and sending down long roots. Very interesting plants, Orchids. I do like them and think they are beautiful but I have never been absolutely captivated by them. I always think of them as spoilt damsels wanting all the attention and I am never sure is it the right one!
Hi Titania,
Thanks for dropping in and commenting. Yes, orchids are a world into themselves and I’m amazed at the patience of those who become hooked on growing and cultivating them. Such ardor!
Here, the Arundina is the only orchid in our “garden,” but we do have many orchids growing wild in the trees. The spoilt damsel attribute more or less vanishes here in their natural setting.
Thanks for the great, detailed post on this plant! Here in Southern California a few orchids will do fairly well in the ground, and this is one of them, even with our occasional frosts. A neighbor has some and they’re pretty dramatic when they do their thing! Hmmm…maybe time to plant some of my own…
Hi James,
Nice to hear from you and to learn that Arundina does well in Southern California. They can indeed be very dramatic – especially in full sun.
I’m seriously considering moving our entire, small, stand, which I’m sure they would appreciate.
Very nice article.
We have planted 35 or so Bamboo Orchids in the garden areas of our yard. We live in South florida so the climate is perfect for them. The stems leaves and flowers are a beautiful thing to behold.
Do you recommend a specific blend of fertilizer for them? We would like to encourage continued flower growth throughout the year.
Thank you:
Mark
Hi Mark,
Sorry for the delayed response – we’ve been without internet for a few days.
It happens that these Bamboo Orchids are growing in one of the few fertile-soil areas on our property, so we have given them no special care. They do not, however, bloom year-round, so I’m afraid I’m not much help to you.
One thing I should mention, though, is that they need more direct sunlight than they have at our place, and we’ll probably move this plant when we have nothing more urgent to deal with. As it is, they tend to lean into the sun.
Nice to hear from you.
Mary
I just bought three beautiful bamboo orchids and
I am planning to plant them around my swiming
pool. We live in SOUTH fLORIDA.
Will it be better to plant them on the ground or
put them on big planter .
Will appreciate your advice .
Thank you.
SM
Hello Simeon,
All I can tell you is that everyone here in Panama grows their bamboo orchids in the ground. Your vendor or your local garden club could provide you with a better answer than I can for South Florida. Good luck with it and do enjoy! It’s a beautiful and interesting plant.
Mary
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Hi, Just bought 2, live in south florida, the hang tag says to mix humus and bark with mother earth then plant. Cannot find humus don’t know what they are talking about. Help please.
Geri
Geri,
Humus is decomposed organic material mixed with soil. It’s fertile black dirt, in other words. If you can’t find a source of humus, try potting soil. The truth is, though, these bamboo orchids of mine are growing in relatively poor soil, and I certainly did not add bark to it before planting. So if your garden soil is half-way decent, you can probably plant them directly into it.
Good luck!
Mary
Thanks for your very insightful information. I am visiting a friend in Tampa Fl central west coast area and they have your orchid and it seems to be doing well. This plant stands about three feet tall and is in full bloom. It does get some what cool here so they cover it at night. I will be visiting again and will give an update. Happy upcoming holidays.
Hi Mary,
wonderful, that you took the time to inform us so lovingly about the Bamboo Orchid!
Bought one at Driftwood Garden Center in Florida and it reads: “full/part sun – moderate water – season all year – fertilizer 6-8-10 – full sun orchid, good in the ground or in containers”
Happy gardening!
Hi Mary
We live in Pinetown, KwaZulu Natal, South Africa. I have owned and loved an arundina graminifolia for some fourteen years. It was given to me as a pot plant which went with us each time we moved.
It has been divided a few times over the years and seems a little sad now. I was hoping to find some secret in your comments but it seems that it is one of those plants to be loved and left in the ground.
I don’t know if this will reach you, but I really enjoyed your article.
Wendy
PS My husband grows Cymbids, Pafs, Dendrobiums, Vandas, and three or four indigineous orchids in the garden … and loves them all.
Hello Wendy,
Thanks so much for commenting. I’m sorry to hear that your Arundina is sad these days, and I wish I could be of help, but I have no idea what to do. If anyone else reading this post has any ideas for Wendy, they’d be greatly appreciated.
Mary
Thank you for the article. I bought this orchid on a visit to Cairns, north Queensland.The person I bought it from told me not to let it out of the pot! I live in temperate climate Brisbane, Australia. The plant is growing well but no flowers yet..but I live in hope
Good luck with your plant, John. It may take a while to develop flowers. I can’t remember how long this plant was in the ground before it bloomed, but it did take a while, even here in the tropics!
A neighbor of mine gve me her potted ground orchid. I planted it in the ground, (in south Florida) and it is blooming up a storm. Some of my neighbors and co-workers would like to give it a try.
How do I “share” my plant? Use cuttings like a bamboo? cut some roots? Has anyone had any success story they would like to share?
Hi Cyndy,
The plant I wrote about was grown from a tuber, so, yes, you could cut some of those “roots” and share them. I’m glad to hear you’re having such good luck with yours.
Mary
Great post, Mary– fascinating… (even if I am getting here a bit late!)
Thanks, Sally. The plant’s still there, and I sometimes think I ought to do a follow-up post on the seeds – clearly the flowers are getting fertilized some way or another. So many things to do. Sigh. ~ Mary
Mary,
Interesting, the first time I saw this type of orchid was in Hawaii alongside the roads and on several of the islands. The next time I saw some was alongside the roads between Tonossi and Cambutal, here in Panama.
I haven’t tried to grow them at home, Chitre, but will in the future.
Enjoy your blog, keep it up.
I’m sure you’ll be able to grow them in Chitre, Jerry. They’re a lot of fun. Thanks for your remarks.
merci pour tous les renseignements sur l’orchidée bambou. je vois cette orchidée sur une terrasse en plein soleil toujours en fleurs .Elle est très belle, j’ai acheté la même depuis 3 mis environ mais pas de fleur, elle a 5 branches que dois-je faire dois-je la rempoter dans un grand pot ou la mettre en terre merci pour vos conseils
merci pour la belle description sur l’ochidée bambou
j’ai acheté cette orchidée bambou depuis trois mois environ elle a 5 branches dois-je la rempoter dans un plus grand pot ou la mettre en pleine terre
Merci. Bonne chance avec votre orchidée!
Hello again, Mary. My bamboo orchid I referred to in January has flowered! The first bud is unfortunately deformed, but more are about to open. Love the look of the plant. From 6 inches it has now grown to almost 2 metres!
Rory…pas en pleine terre..elle semble grandir rapidement! Ce sera bientot partout. Bonne chance d’Australie. John
I just planted an Arundina that i got from a friend. I live on the eastcoast of South Africa and grow a variety of orchids. This is the first time i.ve seen the bamboo orchid and cant wait to see it in blomm. though it will be a while. Thanks for the article!!!
Good luck with your plant, Johan. They’re very popular here in Panama, for good reason. They’re pretty, and they bloom during much of the year.
I have a question at this time and maybe later I will have comments as I However after reading all the comments and this particular website I realize that perhaps I should have planted the orchid in the moss. Soil would have more nutrients right?
Please let me know the appropriate medium for my little Bamboo.
Thank you in advance, Andrea
Andrea,
Yes, you should plant a bamboo orchid in soil. Good luck with it!
Mary
I would like to know where the people in South Florida found their banboo orchids? I live in South Florida and would love to give them a try
I have heard there are a few nurseries down in the Homestead area that carry them and the Homestead farmer’s market is a good place to check as they seem to carry quite a few unusual plants as well as the run of the mill stuff.
I have seen them occasionally at HomeDepot garden store. the containers are never marked, so you have to know what you are looking for and the plants I’ve seen have been beaten down. However, mine was in pretty bad shape when it was given to me, so I would probably take the chance. the 5-gallon container was priced at about $30.00
Thanks, Cyndy, for getting back on this. I hope this comment helps, June.
These orchids are found in Mauritius on the high wet grounds along the highway.
Thanks, YusGob.
Hi Mary,
Have just bought a potted bamboo orchid. It is about two feet high with four flowers and three buds – a total of about twenty stems. I was going to put it into a very large pot in the corner of the stoep (patio in Cape Town) but not sure if it will get enough sunlight. Should I dead head when the flowers fade ?
Graham.
Graham,
Here in Panama the plant does require full sun. The area where we planted ours became more shaded as the years went by because of growth of the surrounding trees. The plant is still fine and blooms well, but the stems tend to lean over, searching for sun.
Dead-head, yes, but I think you’ll find that even after dead-heading, the stalk that produced the flower or flowers will die back. So rather than dead-head, I cut the entire stalk back to the ground. Always checking, of course, that there is new growth coming in.
You may want to watch yours for similar behavior. Start out conservatively and simply dead-head. Then if the stem starts turning brown, just go ahead and cut it back.
Thanks for your comment, Graham. And good luck with this plant. It’s quite attractive.
To John from Brisbane, I’ve been trying to find any nursery in Australia that sells arundina with no success. Do you remember where in Cairns you got yours? My dad grows them beautifully in Los Angeles – they flower every year and grow really well in a giant clump on the side of the house – and I always wanted to try them in Sydney. Hey, I’m surprised to hear you call Brisbane temperate; I’d call it squarely subtropical and perfect for growing arundina. Thanks for a great post, Mary.
Reply to Lance : I bought my plant from Bunnings in Cairns, North Queensland. They are a hardware chain if you don’t know them. My plant is flourishing in my semi-tropical climate and flowering regularly. Love it! John