Tuesday, August 12, 2014

Coleus - I am calling your name! (But what is it?)

Many gardeners and naturalists are frustrated when we botanists change the scientific names of species. I feel frustrated too, when the crown vetch changes its gorgeous, easy-to-remember (for me) name Coronilla varia, to Securigera varia. Now the genus name sounds like a financial security company, not like a gorgeous crown of pink flowers.

But change happen, and it happens for a good reason. We are sorting out old problems and making things better and more logical in the long run. Keep on reading and you will find out what
Coleus hybrids.
(cc) photo by Pharaoh Hound on Wikimedia.
Wild species change genus for mainly one reason. We try to classify all species with their closest relatives, so that everything in a genus comes from one common ancestor species. That means, all species has one origin back in time and share a common history. To figure out this history and these relationships we use DNA and morphology, and build up evolutionary trees that shows the story of species evolution over time.

Of course, when most plants were first described, they weren't part of evolutionary studies. We first started to construct evolutionary trees using DNA and computers in the late 1980s. In the beginning of botanical taxonomy at Linnaeus' time we didn't even know about evolutionary theory, since that came about in the 1860s with Darwin. The start date for botanical nomenclature is Linnaeus book Species Plantarum from 1753. Before recent times, scientists gave species their scientific placement and names based on overall similarity or dissimilarity, not evolutionary relationships.

In the blogpost about "Magilla Perilla" we listed the scientific name for coleus as Solenostemon scutellarioides. We also listed two older synonyms as Plectranthus scutellarioides and Coleus blumei. A few weeks ago we e-mailed botanist Alan Paton, who works on the evolution of this plant group at Royal Botanic Gardens, Kew in London, and asked him, "What is the correct species name for coleus, for real, and where does it belong?" 

His answer was maybe not what you expect. He said:
"I'm writing up the research at the moment. [...] Plectranthus including some other genera on one hand and Coleus and some other relations including Solenostemon form sister clades. The actual picture with denser sampling shows a slightly more complex picture than these earlier papers; but they give an outline which suggests Coleus should be recognized and Solenostemon would be embedded within it."

What does this mean?  Be prepared to see the scientific name your garden coleus change back to original genus Coleus in the near future, and Solenostemon will be no more (it will be merged into Coleus). Plectranthus will still be around but with fewer species and not include your garden coleus. So, coleus will be a Coleus again, which is very nice, and certainly easy to remember. It has been a mess with these names, but Alan is sorting it all out, once and for all. Check back here on the Botanical Accuracy blog when his paper comes out for an update.

It is really all about getting the right species in the right place in the giant evolutionary family tree, which includes over 300 000 plant species in the world. No wonder it is a little chaotic at times. But we have to do it, and we have to use the most updated scientific names possible to talk to each other about plants and understand our plants, across over the world. It is all part of the progress of knowledge.  And sometimes increased knowledge isn't that convenient to begin with.


Paton, A. J., et al. Phylogeny and evolution of basils and allies (Ocimeae, Labiatae) based on three plastid DNA regions. 2004. Molecular Phylogenetics and Evolution 31: 277-299.

Lukhoba, C. W., M. SJ Simmonds, & A.J. Paton. 2006. Plectranthus: A review of ethnobotanical uses. Journal of Ethnopharmacology 103: 1-24.

'What is in a (PLANT) name?' on the FLORIDATA website

Update on the magics of "Magilla Perilla"

Art Tucker and I have been getting a few e-mails about the blogpost explaining that Magilla Perilla is just a cultivar of the regular Coleus.  We thought we should clarify a few things for those of you that wonder and ponder the naming of plants.
  1. Just because a name is listed in large, well-known databases run by organizations such as Royal Horticultural Society, doesn't mean the name is correct and accurate.  Many times common mistakes have been perpetuated throughout the online or printed publishing world. Often new facts have come to our attention, but the name has not yet been corrected by most sources. In printed books the mistake will live on until a new edition comes out.
  2. Magilla Perilla is a coleus.  That has been shown by looking at scientific evidence such as anther morphology and annual versus perennial habitat. (See more information in this newsletter.)
  3. Magilla Perilla is not a member of the Perilla genus.  If you are not convinced, grow some Perilla, some coleus, and then some 'Magilla Perilla'.  Do your own scientific studies and compare.  Hands-on science in the garden or backyard is a great thing.
  4. What is the scientific genus name of coleus?  Well, that has now turned into a separate issue, and justifies its own blogpost, which will follow this one. 
Diagram showing where "Magilla Perilla" belongs = with the coleus, not the Perilla.
Copyright by BotanicalAccuracy.com

Wednesday, July 23, 2014

Dandelions - mistakes in the field

Dandelions are ubiquitous plants, common in fields and gardens, and also both beloved and hated.  We love their fluffy fruiting heads with their wind-blown small parachute seeds.  It is probably one of the most well-known plants in society (except for some common ones that we grow on purpose).

However, not only dandelions have these types of fruits, and some of the popular photos of dandelions are actually other species. The most common mix-up is with Tragopogon species, goat beards. Both are members of the sunflower family, the Asteraceae.  How do you tell them apart?
Dandelion (Taraxacum)
from Lindman's flora, public domain.

The common dandelion (Taraxacum officinale) has:
  • yellow flowers (each head have many tiny, tiny flowers)
  • leaves that are lobed with large teeth
  • leaves in a rosette near the ground, no leaves on the flower stalk
  • fruiting heads about 3-5 cm in diameter (up to 2 inches)
  • the green bracts under the flowering  head are relatively short, and they barely just reach the full radius of the fruiting head.
  • there are more seeds in each head

Note the difference in the leaves and bracts to the leaves of goat's beard.

In the sunflower family, each seed is also a fruit.  So a sunflower seed is a little 1-seeded nut.

Goatbeards (Tragopogon sp. ) have:
Goatsbeard (Tragopogon),
from Thomé (1885), public domain
  • yellow or purple flowers (each head have many tiny, tiny flowers)
  • leaves that do not have lobes, and are very long and narrow ending in a long sharp point
  • leaves are present on the flower stalk
  • fruiting heads usually over 5 cm (over 2 inches)
  • the green bracts under the flowering  head are long, reaching beyond the full radius of the expanded fruiting head
  • you can blow these seeds away too
  • Other names for these plants are salsify and goat's beard. 

Below are some examples of stock photos that are sold as dandelion photos but actually are other species. Most photos marked as dandelions are correct, but a few are not. If you spend $40 and upwards on stock photos, I think you should assume you get the right species, don't you?
istockphoto for sale by user sunnybeach, marked as dandelion but showing goatsbeard.
Note the two long bracts hanging down from the fruiting head near the stem.
(Screenshot by BotanicalAccuracy.com, istockphoto image # 171660950.)
Another stockphoto, this time from Getty images, also showing goatsbeard (note long narrow and non-dented leaves). (Screenshot by BotanicalAccuracy.com, gettyimages photo # 128072731)
More examples on this Pinterest board: 'Dandelions' that are not real dandelions.

Friday, July 11, 2014

Artemisia, a spelling misery

The large genus Artemisia in the sunflower family (Asteraceae) contains some very potent plants and is well-known around the world for a variety of good and bad reasons.   Common English names include sagebrush, wormwood, and mugwort.

For people allergic to pollen, the weedy mugwort (Artemisia vulgaris) is probably a large cause of their respiratory problems in early fall.  For people suffering from malaria, the old Chinese herbal derived from the species Artemisia annua has been developed into a highly efficient anti-malarial medicine.  Then there is Artemisia absinthium, the source of the green-colored alcoholic liquid absinthe of early 20th century fame.  And there is more.  Tarragon, the culinary herb, is a sterile, vegetatively propagated  Artemisia species. There are hundreds of species of Artemisia in the world.

Artemisia absinthium, the plant that is included in absinthe.  Species in this genus have finely divided leaves that often are silvery, and wind-pollinated flowers that are clustered in small, hanging heads.
Image source: Köhler's Medizinal-Pflanzen, public domain, via Wikipedia.

Artemisia is named after the Ancient Greek goddess Artemis, and her name is also used as a source of many names and places outside of botany (see Wikipedia list). She was the deity associated with hunting, childbirth, and wild places. A greek botanist and doctor, Artemisia II of Caria, was named after Artemis, and the name of the genus might have been in her honor, especially since these plants are highly medicinal and have been used as herbals since ancient times.

Surprisingly, in a travel article in The New York Times this weekend about 'absinthe trails' on the border between Switzerland and France, the name of the genus was given as Artemesia, not Artemisia.
"In particular, its namesake ingredient, grand wormwood — Artemesia absinthum in Latin, and simply called “absinthe” in French — might have been found all over Europe, but the type of wormwood that grew in the Val-de-Travers and nearby Franche-Comté was said to be vastly superior."  (source)
Yes, The New York Times also didn't italicize the scientific name, but they apparently never do.  But, for a newspaper that pride themselves on accuracy and correct facts and grammar, scientific names do not seem to get spell-checked a lot.  On May 30, 2014, they published an article on dandelions and it included this sentence:

"The dandelion (Taraxacum officianale) arrived with the first Europeans and can now be found throughout North America. "   (source)

The correct name is Taraxacum officinale, for this most ubiquitous of our lawn weeds. No idea how that extra 'a' got in there...  For biology, this is as much of a mistake as misspelling Obama or Boehner in political writing. For more on formatting and use of scientific names, take a look at this blogpost.

Despite Artemisia being widely used and present, the genus name is often misspelled.  The spelling as Artemesia is common (example 1, example 2), and often Artemisia herbals are sold under 'Artemesia' even if the bottle label correctly says 'Artemisia'.  Is there something in the sound of this name that make us misspell this name inadvertently?

"Magic Seed 100 Mugwort Seeds Artemesia" for sale on Amazon.com by Magic Seed company.
Screenshot by BotanicalAccuracy.com.
 To conclude, here are seeds of mugwort (as 'Artemesia Vulgaris') for sale on Amazon.com. It should be Artemisia vulgaris.   The ad also states "Easy to grow, grows like crazy once established'.  Yes, indeed. It is a common, noxious weed and regulated in some states, and a not something you want to have in your vegetable garden.  If you need some mugwort, you will probably find it really easily anyway, without having to grow it from seed.

(It should be noted that the spelling 'Artemesia' is used for a music band, as a family or given name, and for some buildings. But it isn't used for the plant. )

Wednesday, July 2, 2014

RQ: Use of scientific names as English words

READER QUESTION: If an article lists a series of plants, such as "osmundas, polystichums, and polypodies," should the names be capitalized and italicized?

Osmunda regalis, known as royal fern in English.
(Image from T. Moore, The ferns of Great Britain
and Ireland
, 1856, public domain, via Wikipedia.)
Answer: No. In this case the three fern genera Osmunda, Polystichum, and Polypodium are used as English words, and function as common names, so the example give above is fine.

You could capitalize the names (as 'Osmundas'), but you don't have to, and I think it is better if common names are generally not capitalized. We don't capitalize words like cat, dog, human, apple, and such common names. And if these scientific genus names are used as English common names, then they should not be in italics either. There are many examples where scientific genus names of plants are used in English, for example geranium, calla, petunia...

Wednesday, June 25, 2014

The species names of citrus - a sweet, sour, and sticky mess

Everybody knows the great and tasty citrus fruits - lemon, lime, orange, grapefruit, tangerine, and clementine, and maybe even the more rare bergamot, pomelo, tangelo, kumquat, yuzu, and tangelo.

Various slices of citrus fruits.  (Image from USDA, public domain.)
Since ancient times these plants have been cultivated, domesticated, and used by humans, and hybridization (on purpose or accidental) have created new hybrids. Citrus plants really do like to hybridize and since many of these hybridization and domestication events happened in the past it has been really hard to figure out these questions:
1) What is a species? (biological boundaries and evolution)
2) What is a hybrid? (= cross between two species, biology, evolution, and genetics)
3) What are the parent species of a hybrid? (genetics)
4) What is the correct scientific name for a species or a hybrid? (scientific nomenclature)

With the help of Dr. David Mabberley, an expert on the genus Citrus, I tried to sort this out since so many scientific names for citrus used on beauty and body products are inconsistent and sometimes flat out wrong and need to be updated. Please note that this is a work in progress for science, and that more research is needed to clarify relationships further.  Citrus relationships are a very messy business, indeed. So, here is the most up-to-date information, as far as I can discern.

This is a summary picture of the current hypotheses of the relationships of the most common species and hybrids of Citrus:

Origins and scientific names for the most commonly cultivated citrus fruits. 
Based on data from D.J. Mabberley's publications.

In botanical taxonomy a species (*) can only have one current and unique scientific name.  Other names are synonyms and their use should be phased out, and only be listed as synonyms in publications. This is to ease the communication and understanding in botany, horticulture, ethnobotany, and agriculture. We should all know what we talk about and we should talk about the same thing when we use a species name, right?
(* except for some fungi, but the mycologists are sorting that out now too, slowly. )

Hybrids either get their parents' names with an 'x' in between parent names (mother listed first), or a brand new species epithet preceded by a 'x'.  So, in the figure above, the name for orange can be listed as Citrus maxima x Citrus reticulata, or Citrus x aurantium.  You often see the name Citrus sinensis or Citrus x sinensis for oranges, but those are synonym names that should not be used anymore.

The group Citrus x aurantium includes a large array of different cultivars and varieties, such as orange, tangor, grapefruit, bitter orange, clementine and tangelo.  This is because the initial hybrids where then back-crossed to different parents, so Citrus x aurantium is really a large hybrid complex. 

So, what are then the most up to date names for cultivated and commercial citrus fruits? Here they are:

Common name
Current scientific name
Common inaccurate botanical and ingredient names
Citrus × limon
Citrus aurantium var. bergamia, Citrus bergamia
bitter orange
Citrus × aurantium
Citrus amara, Citrus aurantium ssp. amara, Citrus iyo
Citrus reticulata
Citrus x reticulata
Citrus medica
Citrus medica var. acida
Citrus × aurantium
Citrus clementina
Citrus × aurantium
Citrus paradisi, Citrus × paradisi
kaffir lime (now called makrut lime)
Citrus hystrix

Citrus japonica

Citrus × limon
Citrus limon, Citrus medica var. limon
Citrus × aurantiifolia
Citrus aurantifolia
makrut lime
Citrus hystrix

Citrus reticulata
Citrus x reticulata
Citrus × aurantium
Citrus aurantium, Citrus aurantium var. sinensis, Citrus sinensis, Citrus × sinensis
Citrus maxima
Citrus grandis
Citrus reticulata
Citrus unshiu
Tahiti lime (seedless)
Citrus x latifolia

Citrus × aurantium
Citrus tangelo
Citrus reticulata
Citrus x reticulata,  Citrus × tangerina
Citrus × aurantium
Citrus nobilis, Citrus x nobilis
Citrus × junos
Citrus junos

Many of the commercial, non-commercial, government or non-profit databases and publications do not use these updated names.  They are often lagging behind and changing names take time.

Want to read more about the delicious history and taxonomy of citrus plants?  Try these scientific papers if you want something more substantial than Wikipedia
    Mabberley, D. J. 1997. A classification for edible Citrus (Rutaceae). Telopea 7: 167-172.
    Mabberley, D. J. 2004. Citrus(Rutaceae): A review of recent advances in etymology, systematics, and medical applications. Blumea 49: 481-498 
     Zhang, D. & D. J. Mabberley.  Citrus in Flora of China. [Lots of interesting information here!]
    Li, X., R. Xie, Z. Lu, & Z. Zhou. 2010. The origin of cultivated Citrus as inferred from internal transcribed spacer and chloroplast DNA sequence and Amplified Fragment Length Polymorphism fingerprints. Journal of the American Society for Horticultural Science 135: 341-350. [Note - some of their results do not agree with the parent hypotheses presented above.]
    (Many thanks to Dr. David J. Mabberley for expert help and information for this post.)

    Thursday, March 27, 2014

    New logo for botanical detectives...

    Botanical Accuracy has gotten a new custom-made logo designed by Clayton Leadbetter.  Love it! Thanks, Clayton!

    Flowering ferns and other mythical greens

    The Philadelphia Flower Show is a paradise for winter-weary gardeners.  It can also be great fodder for botanical accuracy blog posts, but I have to say that this year's show was a lot better than usual. It was a delight to be there in this seemingly perpetual winter.  As for botanical inaccuracies, there was only one that stared you in the face, label and all.
    "Flowering Ferns", label seen at Philadelphia Flower Show.
    Photo © BotanicalAccuracy.com.
    This label is from a Dutch company's booth where they were briskly selling "Flowering ferns".  How can that be? Isn't that like unicorns or flying horses? A combination of features that has never evolved, in horses, or in ferns.

    So what is wrong with flowering ferns, apart from the fact that they don't exist?  On the tree of life of plants, ferns (and horsetails) are located above the mosses and liverworts at the base, and below the conifers (spruces, pines, etc.) and flowering plants.  Conifers and flowering plans have seeds, but ferns, lycopods, and mosses have spores spread from sporangia, never seeds. Flowers and fruits only occur in angiosperms (flowering plants), a group that evolved a lot later than ferns. So what is in this bag for sale in this booth? A fern or a flowering plant?

    "Flowering Ferns" packet, seen at Philadelphia Flower Show.
    Photo © BotanicalAccuracy.com.
    It turns out to be a flowering plant with fern-like leaves. The species is Incarvillea delavayi. It is a member of the family of Bignoniaceae (bignons), together with trumpet creeper (Campsis), jacaranda (Jacaranda), and African tulip tree (Spathodea).  Common names for this species are hardy gloxinia, incarvillea, garden gloxinia, and Delavays trumpet flower.  To add the inaccurate name 'flowering ferns', just add confusion. 

    Wednesday, February 26, 2014

    Pollen allergy? Not from thistles

    This ad is marketing the allergy medicine Singulair (Merck) and it is titled 'go nose to nose with allergies'.  And right next to the nose is a very spiny, evil-looking thistle head with an abundance of red, small tubular flowers ready to release their pollen.

    The problem is that people are mostly allergic to wind-pollinated plants that release dust clouds of dry pollen grains that fly through the air freely and land in our noses, eyes, and mouths.  The non-wind pollinated plants, such as thistles, get visited by insects that carry the pollen from flower to flower.  For the pollen to be a carried by insects, the pollen needs to be sticky so it stays on the animal.  And sticky pollen doesn't fly through the air freely and enters your nose as dust.  So, thistles are not common allergy plants at all.

    The most common allergy-inducing plants are wind-pollinated grasses, some weeds (which is a group of a variety of unrelated species), and trees in the plant families containing oaks, birches, and other wind-pollinated trees.  But too often the insect-flowering plants that flower at the same time as the wind-pollinated allergens get the blame, as in this case.

    I also think the Singulair marketers rather have a spiny evil-looking weed like the thistle in the ad, than a fragile grass with rather small, obscure flowers. But the use of the thistle spreads misinformation. People might start to pull up goldenrods, thistles, and clover because they think they cause pollen allergies, which is not true at all. If I was working at Merck, the producer of Singulair, I would be very embarrassed over this mistake.  

    Tuesday, February 11, 2014

    Are there cattails among the nymphs in the waterlilies?

    Sometimes you run into botanical mistakes that just makes no sense.  Mistakes that are so strange, that you wonder not just want the author was thinking, but really, HOW did they get this wrong...  A reader of this blog (RO) sent me this example of such a preposterous mistake:

    On Virginia Tech's online Weed Identification Guide, when you search for cattails, you find this:

    Screenshot from Virginia Tech Weed Identification guide by BotanicalAccuracy.com.
    A nice page with a species description, but... the genus is wrong.  Cattail belongs to Typha (in the family Typhaceae, they have their own little family).  Here is a typical cattail in fruit:
    Typha latifolia_10
    A pair of cattail 'cigars' which contain the developing fruits.
    Photo by Amadej Trnkoczy on Flickr, Creative Commons. 

    Instead of Typha, the listed genus name is Nympha, which not only is a non-existent genus name, but probably was meant to be Nymphaea, the waterlily genus.  Sure, water lilies often grow very close to cattails in the edges of lakes or ditches, but they are completely different plants. Compare here:
    waterlily banner
    A great pair of Nymphaea, water lilies. Photo by Vilseskogen on Flickr, Creative Commons.

    Nymphaea is of course named after the Greek nymphs, while Typha also comes from a greek word 'typhos', which is the ancient name for this plant.  Apparently cattails have long been associated with mythological creatures such as serpents and dragons.

    The same information and mistake is showing up in University of Missouri's Weed ID iphone app, and they must have some kind of collaboration with the originators of Virginia Tech's Weed data.

    My main issue here is that universities that put out online (or printed) botanical tools for the general public need to get at least the basic science correct.  People use these tools, which is great, but they will (and should) assume that the information is accurate, especially if if it is provided by a research and teaching university.

    (Thanks to RO for sending me the link to the botanically inaccurate page.)