Thank you for your help. I will check one in the morning and try to pull a plant out so that I can get a photo of its roots. I do not ever recall seeing any type of nodes on the root structure so I am not sure about the it being C. benghalensis but I will double check. The house where it grew "naturally" was built in the 50's and my folks were the second owners on record. Many of their neighbor's were the original purchasers of their homes and none of them knew what this was nor did they have it growing in their yards. This makes me wonder if the original owners of my parents' home did not bring the plant with them when they moved in or perhaps were given a cutting at some point in time. If so, it would open up the geo location possibilities.

Again, thank you so much for all of the assistance. It is most appreciated.

I had thought Commelina benghalensis was a possibility, the flowers don't always 'appear' to be purplish. It looks to have some hairs which this plant doesn't, the leaves and flowers do look a good match though.

http://nathistoc.bio.uci.edu/p...

http://www.hear.org/pier/image...

http://www.hear.org/pier/speci...

http://www.cabi.org/isc/datash...

Commelina communis was the other one which I thought possible, it grows to more than 1 metre. There's a key on a pdf ..

http://flora.huh.harvard.edu/c...

The flower stems come from the leaf blade which seems to rule communis out.

http://www.invasive.org/browse...

On the key above: Commelina benghalensis "Involucral bracts borne opposite leaves.......Petals blue".

https://sites.google.com/site/...

Just wanted to mention that there are some Commelinas native to the US. For some reason, almost every time there's a discussion about them, the assumption is made that it's an invasive exotic, usually C. communis in particular, even though that's not the only exotic Commelina (in the US.) Most literature about 'weeds' seems to make the same assumption, and/or fail to mention that there are natives. Strange, blue is the rarest flower color, yet this genus seems to have so few fans even though there seems to be a huge demand for blue flowers, ground covers in general, and so many other (definitively invasive) ground cover type plants have large numbers of ardent fans.

Hopefully you've found a native, if not native to the exact location in CA. That it has 3 prominent petals eliminates many of them, but it sounds like you've realized that already. Going deeper into this genus gives me a headache, too many botanical anatomy words that I don't know - good luck! Sure is pretty!

Horntoad, while taking photos of the spathe this morning, I noticed that it is not the same shape as many of the Commelinas:



I also tried to get a photo of the smallest petal that is blue and white. Please forgive me for the quality. My camera is really struggling to capture something this small:



I phoned my mother last night to let her know that this plant has been positively id'd as a Commelina. She still has a separate pot of it growing at her house so she was quite pleased that this portion of the mystery has been solved. I did pull up some roots (but not the main plant)to verify that my memory was correct and there are no nodes on the roots. I guess that is the main reason why I am hesitant about calling it C.benghalensis. This Commelina definitely spreads by re-rooting wherever the stems contact the soil but not by sending out underground runners. Oddly, however, this only happens maybe 5% of the time. The vast majority of stems in contact with soil have not rooted.

JRsbugs, thank you for the links. They are very informative. I keep checking C.communis, too, due to the length of some of these runners. Upon closer inspection, I found that each mature leaf node seems to sprout 2 to 4 hairs. I took a photo of this:



Purpleinopp, it is the oddest little creature. Our neighborhood back then was one of those typical 50's/60's type of places where everyone stayed permanently and all of the neighbors knew one another well. What I find strange is that none of them had this plant volunteer in their gardens so I don't know if it was an odd seed, a selective native, or something intentionally planted by the one previous owner. I absolutely agree with you about natives and "weeds". It is sad that the information out there isn't more accurate. Also, it is one of the truest blues out there that I have seen - almost identical to the lighter sky blue lobelia erinus.

AlwaysbehindMN, I have noticed the same thing about improving the tilthe and the shallow roots. It really makes a lovely groundcover - even if just temporary.

Did you see the "distinguishing characteristics" of Commelina benghalensis OG?

reddish brown hairs on leaf sheath

http://www.hear.org/pier/speci...

I did but I am a bit confused. If you look at this photo:
http://www.saveourwaterwaysnow... ,
it shows a rather hairy individual - mine looks as if it has severe alopecia in comparison. Is there that much variation between specimens? I do, however, think I may have gained a little more clarity on the root structure. Although all of the links that I had read spoke about the underground nodes, etc, I came across a site that said that this was not necessarily true. This site distinguishes between 2 types of C. benghalensis:

http://www.issg.org/database/s...

To quote them:

"Commelina benghalensis grows as a perennial in tropical climates and as an annual in the temperate United States. This difference in lifecycle can be associated with a difference in ploidy levels, with tropical C. benghalensis being hexaploid and temperate being diploid. Tropical hexaploid plants rarely have subterranean flowers."

Mine is most definitely perennial and I am certain that there are no subterranean flowers or nodes (I cannot imagine that neither my mother nor I would come across them if they were there). Would it be reasonable to hypothesize that this individual (the one in our yards) is hexaploid? The only reason I am hesistant to suggest this is that our specimen is hardy with no die-back what-so-ever even if the temps bounce down into the low 30's/high20's on the stray winter night - not quite a tropical environment. Could you share your thoughts? Thank you so much for all of the help!

I forgot to add that the height quoted for C. benghalensis bothers me. Our individual is much larger

The split in the spathe only going two thirds the way to the peduncle would rule out C. communis.
The small blue petal (the two white ones are sepals) and the lack of auricles would seem to rule out C. erecta. Add to that the red hairs on the sheath would indicate Commelina benghalensis.

I am afraid I did not label the photo very clearly. The blue petal is actually blue with a white center. The blue petal I examined yesterday was white with the heavy blue edge and a thin blue strip down the middle. There seems to be a little variation between flowers. Not great by any stretch, but each flower appears to be slightly different in regard to this one petal.

Do you have any thoughts regarding the annual/perennial, hexaploid/diploid issue? I really appreciate your help, Jay.

Annual or sometimes perennial herb, known as Benghal Dayflower, Tropical Spiderwort, Wandering Jew

Stems have a high moisture content, and once well rooted the plant can survive for long periods without moisture availability and can then grow rapidly on the onset of rains.

None of the other weedy species have brown-tipped hairs

Mentioned are C. benghalensis, C. diffusa (the spathe open along one edge, leaves are narrower), C. forskalaei (spathe is sealed, but the leaves are narrower).

http://www.saveourwaterwaysnow...

C. benghalensis probably does vary in the hairiness according to it's location.

Commelina benghalensis can be an annual or perennial herb

The leaf sheath is covered in red and sometimes white hairs at the apex which is a primary identification factor for this species.

The upper two flower petals are blue to lilac in color, with the lower petal lighter in color or white and much less prominent

"Commelina benghalensis grows as a perennial in tropical climates and as an annual in the temperate United States. This difference in lifecycle can be associated with a difference in ploidy levels, with tropical C. benghalensis being hexaploid and temperate being diploid. Tropical hexaploid plants rarely have subterranean flowers."

http://www.issg.org/database/s...

Involucral bracts borne opposite leaves

http://flora.huh.harvard.edu/c...

I think there's enough clues there to say it is Commelina benghalensis.

Please excuse this sidebar, but Janet, you pasted something as if it was a clue to ID, but prefaced it with your comment, "probably does vary in the hairiness according to it's location." You seem to really know what you're doing, and I've never gotten a definitive answer asking anywhere about this out of context, the discussion gets totally confused. I think you can understand my question, and probably have a darn good answer, not to mention the other very knowledgeable people who visit this forum.

"Commelina benghalensis can be an annual or perennial herb."

How can there be that variability within a species? Isn't this something that defines a species, whether or not it's annual vs. perennial? Just because an occasional individual doesn't live for more than a year doesn't negate that a species is perennial, or does it? What does it mean when a source says that? Are they talking about hardiness ("an annual up north") or that a high number of individuals reliably don't live long regardless of location/climate? It always seems to me like this statement is coming from a person who doesn't understand hardiness boundaries, not a scientific fact, and I've always blown it off before. On this rare new opportunity when someone such as yourself pastes it, I can't help but ask, strike while the iron's hot, so to speak. Please explain/elaborate?! Much appreciated in advance!

The fact that some species can be called both annual or perennial usually relates to the hardiness of a plant Tiffany. In a warmer climate some plants will be perennial, in a colder climate the same plant could be grown in a single season, but the cold winters would kill the plant.

They may or may not set seed which will regrow, seed production is a tricky thing but species usually make seed where hybrids often do not (but many do!), and some hybrids will make offsets instead but that isn't confined to hybrids alone. Species make seed which will often germinate over several years, it will ensure the species survives where some years may not provide the conditions required to grow, some species seed remains viable for many years. Hybrids are developed for their ability to germinate readily and uniformly so people who buy the seed are happy when they get good germination.

When a plant sets seed which grows in the autumn, flowering the following year, it is technically a biennial but is sometimes also called a perennial. I have Geranium yeoi, it sets seed which grows in the autumn and flowers the following year so every year I get flowers. However, the winter of 2010/11 here was extremely harsh so the young plants were killed off. That wasn't the end of them though, there was more seeds which survived on the ground and they grew in the spring with the result for the year 2011 I didn't get flowers but those plants lived until the next year, 2012, and flowered. This species can flower almost all of the year if it's mild, I had a few flowers over the last winter which was quite mild. So, the seed which grew in spring meant I had those plants for almost two years, in that sense you could call them perennial.

And yes, location and climate can make a big difference as to how some plants behave.

purpleinopp said:

"Commelina benghalensis can be an annual or perennial herb."

How can there be that variability within a species? Isn't this something that defines a species, whether or not it's annual vs. perennial? Just because an occasional individual doesn't live for more than a year doesn't negate that a species is perennial, or does it? What does it mean when a source says that? Are they talking about hardiness ("an annual up north") or that a high number of individuals reliably don't live long regardless of location/climate? It always seems to me like this statement is coming from a person who doesn't understand hardiness boundaries, not a scientific fact, and I've always blown it off before. On this rare new opportunity when someone such as yourself pastes it, I can't help but ask, strike while the iron's hot, so to speak. Please explain/elaborate?! Much appreciated in advance!

It goes well beyond hardiness. Many plants exhibit a large amount of "plasticity" in terms of their growth patterns. For example, Musk Thistle (Carduus nutans) is usually classified as a biennial, meaning that the seed germinates in the spring of a given year, the plant grows as a rosette throughout its first growing season, overwinters as a rosette, bolts a flower stalk in the second growing season, and then dies after producing seeds. However, some individual Musk Thistles will germinate in the spring, flower the same year, and die after producing seeds (meaning they are Annuals). Others will germinate in the fall, overwinter as a rosette, and flower and die the next spring (meaning they are Winter Annuals). Others are capable of surviving and blooming over several years (meaning they are Perennials). Musk Thistles are far from alone in this ability to act like an annual, winter annual, biennial, or perennial depending on circumstances. It's a combination of genetic variation between individual plants and environmental conditions.

To answer your first question "How can there be that variability within a species?", with wild plants there is usually a HUGE amount of variability within a species. I've found that gardeners are often taken aback when confronted with that reality. It's a result, I think, of the nature of modern horticulture. Most plants grown in gardens these days are cultivars. In many cases, individual plants of a given cultivar are clones of each other (i.e. genetically identical). Gardeners have become so accustomed to the idea of any plant with the name "X" being identical (or at least extremely similar) to every other plant with that name that they just assume it's the natural order of things. It's not.

The answer to your second question "Isn't this something that defines a species, whether or not it's annual vs. perennial?" is simple. No, it's not something that defines a species.

TYVM for the inputs! I've always been a straight species kind of gardener, very little experience or interest in cultivar plants. So not asking about appearance of seed offspring, or store-bought plants with cultivar names, just the definitions of annual, perennial.

I've never read a formal description or plant ID key that said a plant was not either annual or perennial (and sometime biennial.) I've never seen a resource that said there was variation in or interpretation of whether or not a plant was annual vs. perennial (or biennial) just that plants can behave as one or the other depending on location/climate. If it's just being used as a matter of personal interpretation, and/or to indicate the behavior of a plant, which I think is what you are both saying, Kent and Janet, I maintain respectful disagreement about these definitions being malleable to personal interpretation, outside the context of behavior.

I don't see any confusion or room for personal subjection in the definitions printed on Wiki for annuals and perennials. The definitions are not variable or malleable regardless of behavior of individuals and/or climatological factors.
http://en.wikipedia.org/wiki/P...
http://en.wikipedia.org/wiki/A...
Biennials:
http://en.wikipedia.org/wiki/B...

There is often criticism of Wiki for printing inaccurate info, so info there is best confirmed through other sources.

Dictionary.com:
http://dictionary.reference.co...
Oxford dictionary:
http://www.oxforddictionaries....
National garden assoc.:
http://assoc.garden.org/course...
Lady Bird Johnson wildflower center:
http://www.wildflower.org/glos...

TX A&M confirms, and addresses the issue of regional/climate behavior, which is a footnote to the issue of annual/perennial/biennial, not part of the definiton:
http://aggie-horticulture.tamu...

Using an example given above, Carduus nutans:
"Musk thistle is usually a biennial, requiring 2 years to complete a reproductive cycle, but may germinate and flower in a single year in warmer climates."
http://www.nps.gov/plants/alie...
PFAF:
http://www.pfaf.org/user/Plant...
TX A&M:
http://www.texasinvasives.org/...

Bringing this back to this discussion, Commelina benghalensis:
Great pics:
http://www.gpnc.org/images/pdf...
Defined as perennial:
http://www.gainvasives.org/pub...
http://en.wikipedia.org/wiki/C...
USDA uses 'duration'
http://plants.usda.gov/core/pr...
"can be" is used here:
http://www.issg.org/database/s...

This site indicates the climatological difference:
http://idao.cirad.fr/content/o...

"Tropical spiderwort is considered a monsoon weed in its native habitat, which is characterized by
rapid germination and completion of the lifecycle during the limited monsoon season while soil moisture is plentiful (Kaul et al., 2002)."
- http://journal.cotton.org/jour...

In the case of this particular plant, an unusual reverse may have been revealed when it was moved to a more hospitable climate. It sounds like this plant has a difficult time surviving perennially in its' native environment because of a dry season. When brought to the moist southeast US, it thrives perennially. If that is accurate, it is understandable why this plant is so successful at being invasive.

From the above example about this Commelina, a classic example of thousands I've seen over the years, it seems that this vagueness ("can be annual or perennial") is also sometimes used when it's not clear whether or not a plant is perennial, so the author speaks about its' behavior. That's really the important thing as far as USING definitions, what a plant can be expected to do in a particular location, hardiness, and that one can never 'save' annuals indefinitely. I'm more firmly convicted in my original thoughts after asking about this, and doing a couple hours of research about it this morning.

Growing a perennial plant in a location where it can't survive permanently doesn't change the fact that it's a perennial. A patch of biennial foxgloves blooms perennially due to the various ages of the individuals. An annual sunflower will never live for years anywhere.

Thanks again for sharing your thoughts and taking the time to do it.

I enjoyed reading this, and I agree that "Growing a perennial plant in a location where it can't survive permanently doesn't change the fact that it's a perennial." But it is not just as true that a plant that grows, set seeds and dies in one year qualifies as a annual? Which is more important, the classification of a plant as a annual or a perennial, or how the plant acts in your own garden? If every single plant in the universe of a species acted as an annual except one, would that make all the others perennials also? Hey, I don't know, I can see both sides.

OT to your post (but the photos in your posts show this, too) and what niggles at me with the identification of this particular plant is the pubescens of the aerial stems which C. benghalensis is noted for but which is lacking in this specimen. Also, the spathes of this specimen show minimal to no pubescens, too, unlike the photos of C. benghalensis and the height is not correct (but perhaps this can be explained by the perennial nature of this specimen???)

Thank you for posting your questions/comments on annual/perennial designation. Again, OT and I apologize for this), in terms of this specific plant, are there 2 different forms of C. benghalensis (one hexaploid, one diploid) which accounts for the perennial/annual definition as ISSG claims? I have not seen any other references to ploidy levels elsewhere.... so is it valid?

What is interesting is the red hairs on the leaf sheath is mentioned as being present in very few species, the other species do not have the broad leaves. I have seen this mentioned in several places, but in none have I seen the hairiness or not of the flower spathes being mentioned as an identifying factor.

There's a lot of info on this pdf:

http://herman.marc.usda.gov/sp...

The argument as to whether a plant can be defined as annual or perennial I think does depend on how anyone views the meaning of each. Even if something acts as an annual in one location, but is perennial in another, should in my view be called whatever the behaviour exhibits for that location. e.g. species X is annual in one location, but is perennial in another location, then they must surely be defined as to how they act for each location? How could a plant be called a perennial if it doesn't behave like a perennial for a certain location? If it grows from seed and dies in one year, then it is 'annual', but if it remains dormant due to dryness but the roots regrow when rain allows it to, then it should be called perennial due to the fact the plant has survived even if not in growth.

I think labelling plants as a definite type of plant, i.e. annual, perennial or biennial is more a means of describing how a plant will behave than being attached to the actual description of the plant. True, some plants can be definitely annual, and some will be permanently perennial with many dying back in a season (not always in winter!) and retaining the roots with growth eyes waiting to spring into life again when conditions allow. Where plants are able to behave in different ways to what people consider to be 'normal' for a certain location should not define, in my opinion, the exact annual/biennial/perennial nature of plants. Perhaps people have tagged plants with these descriptions as a matter of conforming to make information available to the people who want to grow them. Plants don't know about that part of human nature.

Then we get into whether a plant is deciduous, evergreen, or semi-evergreen!

purpleinopp said:
I've never read a formal description or plant ID key that said a plant was not either annual or perennial (and sometime biennial.) I've never seen a resource that said there was variation in or interpretation of whether or not a plant was annual vs. perennial (or biennial) just that plants can behave as one or the other depending on location/climate. If it's just being used as a matter of personal interpretation, and/or to indicate the behavior of a plant, which I think is what you are both saying, Kent and Janet, I maintain respectful disagreement about these definitions being malleable to personal interpretation, outside the context of behavior.

The definitions are not malleable, but the plants most certainly are.

I'll come back to the Musk Thistle example simply because it's easy, but many, many plants behave the same way. I've seen Musk Thistles growing as annuals, winter annuals, biennials, and perennials in the same field at the same time. Environmental conditions play a role, but they aren't the important factor.

Words like "annual" or "perennial" are just inventions of the human mind, an attempt to make sense of an extremely complex world. Plants care not for the boxes we try to fit them in. All they are trying to do is pass their genes from one generation to the next, by whatever means are available to them. For most plants, the variability of those means is quite surprising and spectacular, including acting like a perennial, biennial, or annual depending on what is to their greatest advantage at the moment.

As for the plant keys, there's always a difficult balancing act between accuracy and usability with keys. The more technically accurate they become, the less usable they are. For example, the key sitting in front of me right now says:

26. Inflorescences of spicate racemes borne singly.......Schizachyrium scoparium (little bluestem)

26. Inflorescences of 2-7 spicate racemes............Andropogon gerardii (big bluestem)

That's true probably more than 95% of the time, but it isn't ALWAYS true (big bluestem occasionally produces inflorescences that are borne singly). Keys are designed to point you in the right direction most of the time, but it is impossible for them to be right all of the time (because plants exhibit a LOT of variability ). That said, if you've never seen a key with something like "Plants perennial or annual", you might want to look for some better quality keys . I see that sort of language in keys routinely.

This used to grow all over my Grandmother's yard. I always liked it.