Long vining plant
Very invasive perennial vine. Is pulled every year but keeps coming back. Makes its way underground from garden areas and comes up in middle of lawn. Has been coming up for 25+ years. Large green heart shaped leaves, just like morning glory but larger. Wraps itself around the nearby rhododendron and rose, nearly covering it. Made its way inside crack in house and is growing inside front porch. No thorns, berries, or flowers! From online research, looks just like pipevine but no flowers.
Muskegon County Michigan
I believe this is a plant is in fact pipe vine or Dutchman's pipe (Isotrema macrophyllum, previously known as Aristolochia macrophylla). As you have observed this is a woody perennial vine that was likely introduced to Michigan as an ornamental species. The flowers on this species appear in late-spring to early summer. They are on the smaller side, inconspicuous and usually hidden beneath the foliage, so that might explain why you haven't seen any. The seed develops in a capsule structure in the same location and eventually turns brown. If you are still not finding any evidence of the capsules, it's possible that there is some sort of environmental influence that is disrupting reproduction...but I was not able to find any evidence of this in the literature.
Do you have any photos of the roots? From my literature search, this species appears to reproduce exclusively by seed as the root is reported to be a tap root and there was no mention of rhizomes or stolons (i.e. below and above ground creeping stems, respectively).
I should be able to get a photo of the root later today. I feel pretty confident in your identification of this as pipevine as that was what I was thinking and have other people guess that that is what it is. So, my next question is: How do I kill it? Pulling it up doesn't seem to do much. Is there a chemical I can use to kill it?
The most important thing will be removing the plants before the seeds are formed, so I would suggest acting sooner than later. In areas where it is prone to emerge you could use a preemergence herbicide like Preen (a.i. trifluralin) so long as you are not planting anything desirable in that area from seed.
If the root is a taproot as we suspect, digging that up is one option that will reduce the chances of harming your other plants.If you don't think you can dig it all up I would suggest a cut stump treatment with a product like glyphosate (the active ingredient in Roundup Super Concentrate and others). With a cut stump treatment you paint the herbicide on the stump after cutting it near the soil surface. It is important to make the application within a few minutes of cutting it to ensure maximum uptake. Specific directions for this method are listed on the label. Please see my other comments on using glyphosate at the bottom of this post.
Another product you could use is one of the herbicides directed at killing brush and poison ivy, triclopyr (the active ingredient in BioAdvanced Brushkiller Plus and others). This can be used in a similar manner. It does have the potential to impact future plantings for the rest of the season in that area, unlike glyphosate.
If when you dig up the roots you find that it does have underground stems (i.e. rhizomes), then the use of a herbicide will be more important to ensure success.
I'll keep an eye out for you photo. If you do not want to load it here you can email it to me directly at email@example.com.
When using products containing glyphosate there are a few important points to consider. First, as with any pesticide, remember to read and follow all labeled instructions. Second, glyphosate is a broad-spectrum herbicide, meaning it will injure or kill other plants contacted during the application, so care is needed to avoid green plant material, exposed roots, and injured bark of desired plants. Third, glyphosate is relatively safe in the environment when used as labeled. It adsorbs strongly to soil in most cases (i.e. clay and organic matter), allowing even sensitive crops to be planted shortly after application; meaning no carry-over issues are expected. Fourth, glyphosate alone can take up to 14 days to show full activity under ideal growing conditions. Retreatment of the area may be needed depending on the degree of infestation. Glyphosate is most effective for perennial control in the fall but can be applied anytime the plants are actively growing (temperatures consistently above 50F). Finally, be sure that the product you choose has only the active ingredient glyphosate or glyphosate + pelargonic acid. Products with additional active ingredients may have other unwanted effects and may delay the planting of other plants in the coming season(s).
Here are more photos we took this evening. In a couple I've marked where ground level was on the plant, so you can see what the root looks like. This is not even the whole root - it would break off when pulling it up. The roots themselves are pliable and very long, and sort of woody compared to the green stems and parts of the vine further above ground. We removed about two large garbage bags of this vine and still did not see a single flower, berry, capsule, etc.
I still think this is pipe vine. I am questioning the literature source that I saw where it said it had a tap root. Many sites for gardeners discuss increasing the number of plants by taking rooted shoots...so it may very well have a rhizome and it is just not documented well.
Again it is possible that it is not flowering due to the environment, we see this with other plants, especially if they require a certain day/night length the induce flower and you have any street lights or other exterior light sources. There are other environmental stressors as well. Unfortunately, this is just not a very well described plant as far as biology in the scientific literature.
The cut stump or stem method described above should work plants with rhizomes as the herbicides listed are systemic and will move throughout the plant. Triclopyr would probably be the better choice of products as it is what is prescribed most frequently for persistent perennials. Fall is again the best time to apply (late-August-early October), but you can do it any time the plants are actively growing. Again, you may need to treat more than once as this is a well-established plant(s).