Identification of houseplant which exhibits an odd and rare growth behavior

Asked December 12, 2017, 7:50 PM EST

Dear Extension Service, I am trying to identify a houseplant which displays a remarkable, but very infrequent, odd growing behavior. More than a decade ago a coworker allowed me to transplant a portion of a plant that she kept on the windowsill of the laboratory where we both worked. The coworker did not know (or had forgotten) what kind of plant it is. The small to moderate size (about a foot tall) plant, seems like a cross between a bamboo, fern and asparagus. It grows by sending up new shoots that emerge from the ground (like a bamboo) and begin to “leaf” out while the older shoots slowly yellow and die. I have attached two photos of the plant (bottom and top part). In general, over time, the size/height of the whole plant doesn’t change that much. BUT! and here’s the weird thing: Every once in a blue moon (like every two or three years) one shoot will arise that keeps growing and growing and growing (like a Jack-in-the-Beanstalk occurrence) and doesn’t leaf out (until way, way later). About two months ago one of these rare shoots emerged. This shoot is now over five feet long -and that is measured not from the soil surface but from the normal top of the plant. As it rapidly grows (and I swear it does so near an inch a day) the shoot looks and feels just like a hard thin green wire. It doesn’t have any suckers to hold on to anything and just grows upward (but it will occasionally curve somewhat or even may fall over if not taped to the window in back of it. Although it has no suckers, it does have “nodes” about every two inches and at the node a very small almost indiscernible sharp appendage protrudes from one side. The appendage can prick the skin if the stem is not handled with care. The nodes and appendages are not unique to the long shoot but appear on the regular shoots as well. (On the photo showing the top of the plant you can see -center right- just the first few inches of the weird shoot rising up and exiting the photo frame.) I have attached one additional photo showing the shoot itself. It is not a very good photo. I had to put some cardboard behind the shoot (over the window panes) because the outdoor (sun) light was too strong. Also my camera didn’t want to focus on the shoot but rather on the street scape outside. But I think you can still make out the curvy line that crosses the panes. P.S. The shoot shots were taken about three weeks ago and currently the shoot (which turned to growing vertical again) has reached the ceiling!

Baltimore Maryland houseplants asparagus fern asparagus fern tall bare stem asparagus fern climbing stem asparagus setaceus fern looks like asparagus

2 Responses

This is asparagus fern, botanically known as Asparagus sataceus. It's not a fern, really, but in the same genus as the vegetable asparagus, and is a member of the lily family.

The super long stems you are witnessing are climbing stems. This plant is also known as climbing asparagus. The climbing stems do not occur on young plants, but as plants mature they send out these stems. They can be extremely long--several yards--as you can see. Because it is an extremely tough plant, it has become invasive in some places, including in the U.S.

You can prune off the climbing stems without harming the plant, or enjoy them as an oddity.

ECN

Dear ECN,

Thanks for your reply (and very quick one at that!).

I have already started researching the plant for additional information. (I am a retired scientist -although was a very low level one-, so I love details about all biological organisms.)

The only fact that I came across that seems puzzling is the mention that the plant produces flowers and then small berries. I have never seen flowers on my plant, but I realize that may not be true for every asparagus fern sat under every growing condition. (P.S. not requesting any reply on the flower question. I'ii just keep researching.)

[just joking here] I wonder if the super long shoot is really a periscope sent up by the plant to scout-out the environs (-you said it is considered by some to be invasive). In my case, where the asparagus fern is a houseplant, it could be using the periscope to look for an escape route. (The plant does have a soft life in my house but maybe it doesn’t fully realize that outdoors, life can be challenging.

Most Gratefully,

Keith Young