Batman and Poison Ivy's leaves

The weeds and botanical inaccuracies have also entered the world of comics. In 1966, Batman had a new nemesis, Poison Ivy, a botanist turned bad. (Brilliant!, says the botanist and author of this blog.) The poison ivy plant is one of the most obnoxious weeds of North America.

Issue 181 of DC comics Batman, introducing Poison Ivy for the first time (1966).
The leaves are very similar to true poison ivy, and definitely not English ivy leaves.
© DC Comics, fair use, Wikipedia.

"Poison Ivy is an enemy of Batman. She is depicted as one of the world's most prominent eco-terrorists. She is obsessed with plants, botany, and environmentalism. She uses toxins from plants and her own bloodstream for her criminal activities, which are usually aimed at protecting the natural environment." 
(link to this quote and more information about Poison Ivy at Batman Wiki)

Poison Ivy is of course named after one of North America's most troublesome weeds, the poison ivy (Toxicodendron radicans) in the family Anacardiaceae, same family as the tasty cashew nut and mango, as well as poison oak and poison sumac. This incredibly common woody plant, which can be a shrub or a liana, can cause absolutely horrible allergic dermatitis (skin reaction) with liquid-filled blisters and sores that can take weeks to heal. I know this first hand; I became allergic after moving to the US.

What is interesting with Batman's Poison Ivy is her leafy coverage, which has changed over the years.  Now, remember, most Americans know how poison ivy looks like, 'leaves in three, leave them be'.  In reality the three 'leaves' all belong to the same leaf, which is divided into three separate leaflets.

Poison ivy, leaves are divided into three separate leaflets,
with the middle leaflet stalked. Do not touch this plant!
Photo by Esculpio, public domain, link

But there is a sort of namesake, English (and Irish) ivy (Hedera helix and H. hibernica), which is an unrelated, non-allergenic European plant that has spread through horticulture across North America.  English ivy has simple leaves with three lobes.  Since the common names are similar, and both have green leaves and are climbing, people confuse these plants.

English ivy, with non-divided but lobed leaves. 
Photo by James H. Miller, USDA Forest Service, public domain, link

The subsequent illustrators of Batman's Poison Ivy girl has not always been able to make the distinction between poison ivy and English ivy, and as a result, there is a lot of confusion, especially among non-DC comics people making illustrations, costumes, and such when it comes to the right leaf to draw or use.   

Now, why is this important?  Well, accessorizing Poison Ivy with the wrong plant is kind of giving Luke Skywalker a sunflower to fight with instead of a lightsaber.  One is powerful and strong, the other is just pretty. We are not talking imaginary futuristic plants here, we are talking about living, existing species.  Nobody would name a character 'Lord Bear' and then let him wear a deer skull on his head, now would they? The same thing should matter for plants, especially toxic plants.

So, lets see who got it right? These are true poison ivy leaves.

1966, with correct leaves on.
(c) DC Comics, fair use, link.

Poison ivy on the cover of Joker's Asylum issue 1, 2008 (by DC Comics).
A little hard to tell on this, but there are three-divided leaves on the brown branch at the bottom
right and the leaves do not look like English Ivy at all.
(c) DC Comics, fair use, link. 

A closeup of above illustration.
Source, see above.

Poison Ivy in 1981, also with right leaves on.
© DC Comics, fair use, drawn by Irv Novick and Steve Mitchell, link.

And in the last ten years, things started to go wrong.
Here we have sometimes English ivy instead of Poison Ivy.

The leaves are clearly broad and have three lobes, so English ivy it is.
Promotional art for Batman: Gotham Knights vol. 15 (2001). Illustration by Brian Bolland.
Close-up below. © DC Comics, fair use, link.

English ivy, definitely.
(source, see full image above)

English ivy leaves on Poison Ivy.
© DC Comics (DC Universe online), fair use, link.

9

English ivy abounds on Poison Ivy here.
© DC Comics, fair use, link.

If you are going to buy a Poison Ivy Halloween costume (for $300),
do you want it with English ivy leaves?  Here is one of them.
Screenshot from etsy, © darkpony designs, fair use, link.

 And some are just using some generic leaves, of uncertain species identities or are just unclear:

Poison Ivy in a DC comics from 2006, with leaves in her hair. Closeups below.
© DC Comics, fair use, link.

On the upper frame, she appears to have true poison ivy in her hair.

But on the bottom right frame the leaves suddenly have become more lobed. 
This still possibly could be poison ivy, but it is not typical shapes at all. Looks more like English ivy now.

 And, if you want to simplify, just remove all leaves and
then you don't have to worry about species identity:

Poison Ivy in the animated Batman movies.
© DC Comics, fair use, link.

What Christmas tree is that? A guide to common species

Christmas trees come in many shapes, colors, and species these days.  In the old days you went out into the forest and cut a little (usually rather scraggly-looking) tree of some native tree in your local forests.

Postage stamp from Åland (between Sweden and Finland) showing people
(with saw in hand) bringing home the Christmas tree.
(c) Posten Åland, fair use (link)

For example, in Northern Europe you have only one local species of pine (Scots Pine, Pinus sylvestris), and only one spruce species (Norway Spruce, Picea abies), so a wildcut tree would be one of those species. Unless you brought in a juniper of course (Juniperus communis). In North America there are more local conifers to choose from, but still mostly only a handful.  But these days things are not so simple.

Nowadays, the Christmas tree plantations grow a wide variety of conifer species that might not be local to your area. If you get a tree from a supplier, then the tree might come from far away.  So, finding out what tree you have standing in your living room might not be that simple.

The National Christmas Tree Association has nice photos and descriptions of the most common species. Brooklyn Botanic Garden also has a great clickable key to Christmas tree species with images and descriptions of 15 common species. (Update: Max Payne also has a nice page with descriptions of common Christmas tree species, including several Cupressaceae species.)

First, most Christmas trees are either FIRS (Abies), SPRUCES (Picea), DOUGLAS FIR (Pseudotsuga). or PINES (Pinus). All of these are conifers and have leaves called needles, and cones (except, you rarely see cones on young trees used for Christmas). These plants are quite easy to tell apart and they all belong to the pine family, Pinaceae. See key below.

US Postal stamps showing balsam fir, blue spruce, ponderosa pine and eastern red cedar.
(c) USPS, fair use (link)

Identification key to common Christmas tree genera

1a. Are the needles clustered 2-5 together? Yes - it is a pine (Pinus).
1b. Are needles single? Yes - it is a fir, douglas fir, or spruce. Go to 2.  

2a. Are the needles square in cross-section and green underneath? Yes - it is a spruce (Picea).
2b. Are the needles flat in cross-section and have two white bands underneath? Yes - it is a fir or douglas fir. Go to 3.

3a. The buds at the end of each branch have a sharp tip and are elongated. Yes - it is a douglas fir (Pseudotsuga).
3b. The buds at the end of each branch are blunt at the apex and round. Yes - it is a fir (Abies).

White pine.
Public domain image by Hardyplants, Wikipedia.

PINES (needles grouped in 2-5's)
Needles 5 together: 

• White pine (Pinus strobus) - green to bluish green, needles 5 together, 5-12 (2-4") cm long

Needles 2 together:

• Scots pine [older name: Scotch pine] (Pinus sylvestris) - green, sometimes silvery, needles 2 together, 4-7 cm (2-3") long
• Virginia pine (Pinus virginiana) - green to yellowish green, needles 2 together, 4-7 cm (2-3") long

Norway spruce branch.
(cc) Wikipedi, Wikipedia.

SPRUCES (needles single, square in cross-section, no white bands below each needle; each needle attached to the branch on a little outgrowth; needles attached spirally around branch)

Bluish or greyish tree

• Colorado blue spruce (Picea pungens) - blue green, needles 2-3.5 cm (1-1 1/4") long, with sharp tip
• White spruce (Picea glauca) - bluish to bluish green or gray, needles 1-2 cm (3/8-3/4") long, with blunt tip

Green tree

• Norway spruce (Picea abies) - dark green, needles 1-2.5 cm (1/2-1") long (drooping branches)

Douglas fir branch with cones. The cones are unique,
look at those bracts hanging out betweenthe scales, nothing else looks like that.
(cc) Walter Siegmund, Wikipedia.

DOUGLAS-FIR (needles single, white bands below each needle)

• Douglas-Fir (Pseudotsuga menziesii) - green to blue green, needles soft, 2-4 cm (3/4-1 1/4") long
  

Needles of White Fir showing white lines underneath.
(cc) Walter Siegmund, Wikipedia.

FIRS (needles single, flattened; white bands below each needle; each needles attached directly to the branch; needles attached in two rows along branch)

Needles with two white lines above

• Concolor Fir [White Fir] (Abies concolor) - green to bluish green, needles 2-5 cm (1 1/4-2") long (needles with sharp apices)
•  Caucasian Fir ["Nordmann"] (Abies nordmanniana) -  dark green, needles 1.8–3.5 cm (2/3-1 1/2")

Needles green or silvery above, without lines

• Balsam Fir (Abies balsamea) - dark green, needles 1-4 cm (3/8-1 1/2") long (needles with blunt, notched apex)
• Fraser Fir (Abies fraseri) - silvery to dark blue green, needles 1-2 cm (1/2-1") long (twigs with red hairs)
• Grand Fir (Abies grandis) - green, needles 2-5 (1/2-2") cm long (twigs with grey hairs, needles with blunt, notched apex)
• Noble Fir (Abies procera) - silvery, needles 2-4 cm (1-1 1/2) inches long (needles turn upwards along branches)

(Not included in this blog post are cedars, junipers, and yew, since they are less common as Christmas trees.)
Post updated 28 January 2014 with new information provided by MF.

Christmas Tree of Life does not need a little correction

Christmas Tree of Life Greeting Card
(c) blaghag on Zazzle, fair use.

Here is a cute little Christmas Tree of Life Greeting card designed by 'blaghag' for sale on Zazzle (link) , depicting the evolutionary relationships between reindeer, elves, Santa, and the four plants fir tree, poinsettia, holly and mistletoe, all accurately depicted and with nice scientific names.  Santa and the elves got new fictitious scientific names, nice! The description of the card includes this justification why this is a great card to buy:

"From mistletoe to reindeer, we're all share a common ancestor! Great card to send to your scientific and freethinking friends for the holidays."

I love this card.  It is innovative, fun, and for any science and reason-minded person, a great card.

Phylogenetic trees are read from the root to the tips. In this card, the root (the common ancestor) is at the top, and the branches to the different organisms are branching downwards.  Santa is most closely related to Elves, and reindeers are related to Santa+Elves, since they are all animals, all three of these groups.

Fir trees are conifers, and conifers are part of gymnosperms that are the sister branch/group to flowering plants (such as poinsettia, holly, and mistletoes).  Poinsettia is in the family Euphorbiaceae with spurges and they are placed in a bog group of plants called rosids (near roses, walnuts, birches, and many other plants). Mistletoes are in the family Santalaceae with lots of other parasitic plants, which are placed on another branch, sister to a giant group of plants called asterids.  Holly, an asterid, is in the family Aquifoliaceae. Other asterids are carrots, sunflowers, viburnum, and artichokes, the coffee plant, milkweeds, mint and potatoes.

[This post was updated on January 12, 2014.  The phylogenetic tree shown on the postcard is correct; mistletoes are sisters to holly plants.  The blog text has been changed so it is accurate based on the latest scientific findings. We regret the error. ]

Holly, a winter holiday plant without much need for correction

It is holiday season and we are surrounded by red and green plants that have come to symbolize the Christmas season.

One of the most common is the holly, Ilex aquifolium, I. opaca and related species, in the Aquifoliaceae.  With its dark green, evergreen, spine-tipped and lobed leaves paired with round red berries, it is largely unmistakable and easy to identify and remember. 

European holly, Ilex aquifolium. Plate from Atlas des plantes de France (1891).
Public domain image (Wikimedia). 

It is also really easy to draw, red circles for the berries and lobed, spiny leaves in green.  This is probably the reason this is one of the plants where you find the fewest mistakes when it is depicted as a visual image.

So, for a change, presented here is an example of persistent botanical accuracy, not inaccuracy.  A  Google Image search pulls up hundreds of true holly images, despite a large variety in artistic design and media; here are just one example of a screen shot:

Screenshot of the results of a Google search for 'holly', by BotanicalAccuracy.com

A jasmine is not always a jasmine...

Jasmine (Jasminum) is a wonderfully and strongly scented flowering plant in the olive family (Oleaceae) and its essential oil has been used for millenia as a perfume.  Jasmine flowers are usually white, have five to ten petals and always two stamens in each flower, and they are often hidden in a narrow corolla tube. The plants grow as viny shrubs.  Having only two stamens is a character that is consistent for all olive family members, like olive (of course), lilacs, fringe trees, and goldenbells - and jasmine.  A few jasmine mutant cultivars have filled flowers, so they have more petals of course.

Typical jasmine flower (Jasminum).
(cc) KENSEI on Wikipedia

The problem is that there is a similar genus, mock orange (Philadelphus), which also have white, 4-petaled flowers, and is gorgeously scented.  This commonly cultivated garden shrub is not in the olive family, but in the hydrangea family (Hydrangeaceae), and have lots and lots of stamens inside each flower. The stamens are the yellow 'fluff' in the center of each flower in the photo below.   In Swedish, the common name for mock orange is 'schersmin', and in English it is called 'false jasmine' obviously influenced by the true jasmine and similar scent and flower color.

Typical mock orange flower (Philadelphus).
(cc) Epibase on Wikipedia

So jasmine and mock orange are really easy to tell apart, and they are not closely related plants, but they still get mixed up over and over on food, cosmetics and other product labels.  True jasmine is commonly used in cosmetics and should be listed as various Jasminum extracts and oils on the ingredient label according to the INCI database. Philadelphus flower extract is also approved as an INCI-listed ingredient and used as skin conditioning agent, but it is not listed as 'jasmine' or similar in INCI. So generally speaking, if something smells nice and is called jasmine-something, then it should include Jasminum and have a picture of Jasminum on it, not Philadelphus.  Unfortunately, this is not always the case.

What really is scary is when the producers and sellers of the raw extracts and compounds don't know how to identify the images they use to promote their raw materials sold wholesale to other companies.  M K Exports India sells 'jasmine oil', and illustrates it with this inaccurate figure:

Jasmine oil illustrated with the wrong flowers - the flowers are from mock orange.
Screenshot from M K Exports India's website, by BotanicalAccuracy.com.

Here are some more examples of inaccuracies on labels and in advertising:

Jasmine perfume by Taylor of London, showing Philadelphus flowers, not jasmine.
© Taylor of London, fair use (link)

Home Scents sells a candle named 'jasmine bouquet', with Philadelphus on the label.
© Home Scents, fair use (link)

Tea forté's Jasmine green tea is illustrated with Philadelphus too.
(c) Tea forté, fair use (link)

I also think the Rock Art Brewery's Jasmine Pale Ale Beer from Vermont has Jasminum in it, and not Philadelphus, but it is hard to know for sure. On the outside label is a Philadelphus flower.

Livestrong.com has a web page on the health benefits of jasmine tea, with a stock photo showing a tea cup with, you guessed it, Philadelphus flowers.

Livestrong's web page on jasmine shows mock orange too.
Screenshot from Livestrong.com by BotanicalAccuracy.com

Some companies get it right, of course:

Mark: Jasmine Petals Get Misty Body Mist (with real jasmine flowers)
© Mark, fair use (link)

Yankee Candle's Blooming Jasmine candle has real jasmine on the label.
© Yankee Candle, fair use (link)

So, the two genera Philadelphus and Jasminus are really easy to tell apart even from small photos, but it is obvious that companies and photographers mixed them up.  Both are gorgeous garden or house plants, so it is well-worth to learn the difference between the two.

Canola oil flowers - four or five petals? Ask Trader Joe...

Canola oil is made from the rape seed plant's (several Brassica species) oil rich seeds, a member of the mustard family, the Brassicaceae.  Members of this family can easily be identified by their very typical flowers.  They have 4 petals, often white, yellow, or pink, situated in a cross-wise fashion, which gave them the old family name Cruciferae.  Yes, that is the same word beginning as in crucifix, a cross.

Brassicaceae flowers also have 6 stamens, and a central pistil that will develop into a fruit when/if pollinated.  All mustard plants have the same types of flowers, be it broccoli, garlic mustard, cabbage, arugula, or kohlrabi.  But there is one place, where the rule doesn't hold up...

Canola Oil Spray at Trader Joe's.
(cc) BotanicalAccuracy.com

On the Trader Joe's Canola Oil Spray bottle, sold only at the Trader Joe's supermarket, they have nicely added some flowers from the canola oil plant to the label. Only the flowers look like this:

Close up of Canola Oil Spray cans at Trader Joe's.
(cc) BotanicalAccuracy.com

So, what do we have here?  One flower with four petals (good!), and one flower with five petals (oops!).  And inside each flower, there are three 'things'.   I assume these might be stamens or pistils, but neither makes sense based on the numbers or shapes. The flowers are also never arranged in this particular fashion, but that is a minor point.

So, who cares? Well, if you make a piece of art you certainly can and should have artistic freedom. But, if you illustrate a product, the illustration should provide some knowledge (or excitement) or identification value about the product. It should be the real thing and not introduce errors or misunderstandings into the public's knowledge of plants and the product source.

The number of petals on mustard flowers are strictly determined by that group's bauplan, just like the 4 legs of a dog is based on a strict bauplan among allmammals. You don't go around and see a 5-legged dogs, do you? (5-legged dogs do exist, but are mutants, and they are even rarer in art.)

Here is the real canola:

Flowering canola plant. 
(cc)  Melanie_B (Flying Snow) on Flickr.

So, in this case, the flowers on the label are used to illustrated the origin of a product, canola oil from the canola plant. There are no canola oil flowers with 5 petals. There are no canola oil flowers with 3 non-descript things in the center of the flowers.  If this drawing had been made with 4 petals it would have been equally pretty, and also accurate. So you start to wonder where things went wrong, with the illustrator, with the description to the illustrator, or to the designer of the label?

Reindeer moss is a lichen, not a moss

There are several species of lichens that often are sold as 'mosses', and reindeer lichen is one of the most common.  It is frequently used in holiday and flower decorations and for trees and shrubs in train model making. This type of lichen grows on wet soil and rocks in northern temperate forests and are often harvested and sold commercially.

Here are some examples of wrongly labeled products:

SuperMoss, which is not a moss, but a lichen.
© Supermoss, fair use.

Terrarium necklace with 'moss', which in this case is a lichen.
© Catherine Weitzman for Uncommon Goods. fair use.

"Moss Heart Ring", also made only with a lichen, no moss.
© AbstractAverun on Etsy, fair use

So, who cares if you call it a moss instead of a lichen?  Well, those two organism are about as different as a cat and a katydid, and if you mixed up those two you would care, right? (For those that need to know, a katydid is like a giant, green grasshopper with long antennae. It is an insect, not a mammal, like a cat.)   Reindeer 'moss' and the real mosses might look similar, especially when the lichen is stained artificially green, but they are very, very different and not closely related.

Lichens are a kind of organism that is formed by a fungus and an algae (and bacteria too) that live together in symbiosis.  They can look crusty, leafy, bushy, and branchy and grow on soil, bark, rocks, and leaves.  Often they are only green when wet, otherwise the fungus gives the lichen a more gray, white, yellow, or black color.  The algae inside the lichen is a small microscopic plant that is related to planktonic and marine green algae (and a few green algae that live on land too). Green algae are the precursors to the land plants, including mosses. Lichens never have real leaves. Sometimes you can see lichens with colorful 'cups' on them, those are the sporangia of the fungus that can spread fungal lichen spores around.  Lichens grow extremely slow and can live in many extreme environments (cold, heat, dry, etc.).

Mosses are small land plants that spread with spores from structures called sporangia. Mosses have small real leaves on stems and no flowers.  Mosses are most closely related to ferns, conifers, and flowering plants (instead of algae).

So, to sell something as a moss that is really a lichen is false marketing and provides the wrong product information.  This linguistic mistake and error has been around for a long time, and it is time to change it.  Of course, you can argue that common names are OK even if they are wrong, but why perpetuate such an error when we have the perfectly fine name 'reindeer lichen' already?

So,

CORRECT NAME: Reindeer lichen, caribou lichen

INCORRECT NAME: Reindeer moss, caribou moss

The oily shea-butter tree, should it be Butyrospermum parkii or Vitellaria paradoxa?

The shea-butter tree is a very popular source of a vegetable fat in Africa (more information at Agrifostree). This fat, called shea butter, is now exported and used in many cosmetics products worldwide.

Preparation of Shea butter.
(cc) David Fulmer on Flickr.

Cosmetics and other skin products that include shea butter lists it as  'Butyrospermum Parkii (Shea Butter)', following the INCI database of registered names of cosmetics ingredients.  (As usual, parkii should of course not be capitalized, as pointed out earlier.)

But if you look up the scientific name of the shea-butter tree in current botanical databases, the old Butyrospermum name has changed, and this species is now called Vitellaria paradoxa.  The tree is a member of the Sapotaceae family, famous for its soaping abilities.  The species has two older synonyms in the Butyrospermum genus, B. paradoxum and B. parkii (link). So why isn't INCI updated?  Because there has been a disconnect between the botanical taxonomic world, and the world of plant ingredients in commercial products. 

Shea Butter on LUSH's webpage.
Screen capture by BotanicalAccuracy.com

So companies like LUSH have to use the old, outdated name for this species instead of listing its updated and corrected new name until INCI has updated its database. The same is true for many other plant-derived ingredients that are included in the INCI database.  INCI is working on this, but it will take a while.

So, in summary, the scientific facts for the shea butter plant:

Correct scientific name:  Vitellaria paradoxa

Incorrect name:  Butyrospermum parkii

Is oxeye daisy a Leucanthemum or a Chrysanthemum?

The common garden plant, wildflower and sometimes 'weed' oxeye daisy is often listed under several different Latin names.  How can that be, and which one is right? It is a common plant all over North America, from Texas to Alaska to northern Canada (and Hawaii), and is originally from Europe.

What happened was that originally this yellow and white flower was named Chrysanthemum leucanthemum by Carl Linnaeus on May 1, 1753, in his work Species Plantarum. This book is the starting point for all scientific plant names forever...  Anything published before 1753 doesn't really matter when it comes to scientific names for plants. So for plants, in the beginning, it was Linnaeus.

Oxeye daisy
Illustration from Flora Batava by Kops et al. (1800)
Public domain (Wikipedia)

The French botanist Lamarck disagreed with this classification and wrote in 1779 that this species should be called Leucanthemum vulgare instead.   Botanists discussed and argued about this for a while, but for a long time most people followed Linnaeus' name.

Centuries later it was shown that the genus Chrysanthemum was actually a mixed group of species that weren't that closely related to each other, so the genus would have to be split up into several genera, some of which already had been accepted by previous botanists.  Scientists want only closely related species to belong to the same genus; it is the only thing that makes sense evolutionarily and logically. Linnaeus and other early botanists didn't have evolutionary information as a classification criteria (nor a scientific theory for that matter, that all came with Darwin's theory of natural selection in the late 1800s).

So, Chrysanthemum was split up in the late 1990s.  Which of the subgroups would get the original name Chrysanthemum?  According to the International Code of Nomenclature, which rules the scientific naming of plants, each genus has a type species, and that type species always has to be in the genus it is the type for.  The type for the genus Chrysanthemum was set in 1929 as the species Chrysanthemum coronarium, so oxeye daisy would not get to keep the Chrysanthemum name, neither would the beloved 'mums' in our gardens.  (Things got a little complicated when it later was shown that the type herbarium specimen for Chrysanthemum coronarium actually wasn't that species at all, but that is another story.)

Cultivated chrysanthemums. These are not oxeye daisies.
(cc) Pigsonthewing on Wikimedia

The horticulturalists were upset!  What about their chrysanthemums ('mums'), the popular garden plants that were cultivated all over the world?  Those species were now to be in a genus called Dendranthema.  Slowly this name got accepted under protests from the horticultural industry, until Piers Trehane said in 1995 - hey, we can propose an exception and keep the genus name Chrysanthemum for chrysanthemums by switching the type species to Chrysanthemum indicum (one of the mums),  if enough people vote for this change (here is the proposal for this).  So this was proposed, and after a few years and a vote among botanists, this was passed in 1998/99 as an exception to the rules of The Botanical Code. Now  Chrysanthemum includes the cultivated chrysanthemums, but not the oxeye daisy, and Chrysanthemum coronarium above was to be put in another genus (it ended up in Glebionis).

Then, if oxeye daisy can't be in Chrysanthemum, what genus name should it take?  Luckily, Lamarck had already put it in a genus named Leucanthemum in 1779 when he disagreed with Linnaeus, so the genus name Leucanthemum was available.

When a species changes genus it nearly always keeps its species epithet, the second word in its scientific name. It might change ending sometimes, but the earliest published species epithet stays, it has priority over later published species names.  But, that would be leucanthemum for oxeye daisy, since Linnaeus named it Chrysanthemum leucanthemum.  And that would mean a species named Leucanthemum leucanthemum, with the genus and species epithet the same (a tautonym), which is a total no-no in botany.

bison, which has the scientific name Bison bison
(cc) Syncrude Canada Ltd on Flick

Zoology loves those names, they have them for all kinds of animals, Crex crex (corncrake, a bird), Vulpes vulpes (red fox), Bison bison (bison) and so on. But for oxeye daisy, no way.  So, they had to look for the oldest name among other species epithets used for this species, and that was Lamarck, again.  He had called oxeye daisy Leucanthemum vulgare, and that is the name it has now.

So, Linnaeus was the first person that described this species, but Lamarck now gets the authorship for the current scientific name.

Oxeye daisy, now Leucanthemum vulgare
(cc) Alexander Schneider on Flickr

In conclusion,

CORRECT NAME: Leucanthemum vulgare Lam.

INCORRECT NAME: Chrysanthemum leucanthemum L.
[note, this is not an optional name, this is an old name that shouldn't be used anymore]

Who gets this right?
For example, USDA-PLANTS, Encyclopedia of Life (EoL), Wikipedia, and Royal Horticultural Society.

Who gets it wrong and needs to update their websites?
Well, lots of seed and plant companies (American Meadows, Victory Seeds, etc.), some state departments (Minnesota Dept of Natural Resources, Colorado, etc.), a bunch of garden websites, and WebMD.

[Updated 18 November 2014 with new Chrysanthemum type information provided by DH.  Thanks!]

Wikiherbia: Anise is not the same as star anise

The website wikiherbia promotes itself as the 'complete herb database' and provides information on medicinal plants.  It is in no way complete and lists only a little over 100 plants, and doesn't appear to be a very active website.  However, the information is still there, and people will search for information and find this resource, so it is important that the information is as correct as possible.  Unfortunately, there are some grave errors.

Screenshot of Wikiherbia web page on "anise / Pimpinella Anisum", by BotanicalAccuracy.com

The herb anise (Pimpinella anisum) is featured in wikiherbia, but not only is the Latin name wrongly formatted, but the associated image is of another species, star anise (Illicium verum).  The photo on the web page shows the fruit of star anise. The text is fully focused on anise, not star anise.

Anise and star anise are unrelated plants with different chemical profiles, with the only similarity being that they both have a compound that gives a taste that is somewhat similar to licorice   Anise is a temperate plant in the parsley family (Apiaceae), and star anise is a subtropical/tropical shrub in the family Schisandraceae.

This is how anise (Pimpinella anisum) looks like 

(it is very similar to cilantro, same group of plants):

anise, Pimpinella anisum
Public domain image, from Köhler (1887), Wikimedia

And here is star anise:

star anise, Illicium verum
Public domain image, from Köhler (1897), Wikimedia

Star anise is used for the commercial production of the anti-viral medicine Tamiflu and in Asian cooking, whereas anise is mostly used in European cooking and herbal medicine.

Common mistake: Centaurea vs. Centaurium, both centaury

The two plant genera Centaurea and Centaurium are commonly mixed up, even if they are very different and belong to different families.  Species in Centaurium have the common name centaury in singular, and centauries in plural, and unfortunately you often see this common name in herbal literature or in online sources for Centaurea too. 

CENTAURIUM (centaury) is a member of the gentian family, Gentianaceae.  This genus has about two dozen species, and they are nearly all bright pink.  The flowers have 5 petals, and are small, up to 1.5 cm (1/2 inch) across. (An image search for Centaurium shows all the varying flower types.)

Centaurium pulchellum 
(cc) Christian Fischer, Wikimedia.

CENTAUREA (knapweeds, cornflowers, star-thistles, etc.) is a member of the sunflower family, Asteraceae. There are hundreds of species in this genus, and they all have small feathery-looking flowers assembled in a tight flower head.  The petals can be white, blue, pink, or purple. The flowers along the edge are longer, and the ones in the center of the flower head resembles thistle-flowers, and they are closely related to thistles. (Image search showing the flower variation of Centaurea.)
     The similarity of the genus name Centaurea to Centaurium leds to confusion and the misapplied "centaurium" as a common name.

Centaurea montana
(cc) Jean-Pol Grandmont, Wikimedia

Other differing characters are that Centaurea usually has alternate leaves (Centaurium have opposite leaves) and the flower heads are larger in Centaurea than the single flowers of Centaurium.

So, why do we need to care which centaury that is in the herbal medicine, or reported?  Well, to begin with, these plant groups have completely different chemicals in them.  And for herbal medicine, it is the chemicals that we want, and we want the right ones.  Second, if we suggest to people to use these plants, you better have the right photo (and ingredient) for the plant you intended.  Third, it is just simply embarrassing if you are a company or publisher and gets this wrong.   It is a classic example of why common names can be troublesome if you want to be sure about what plant that was used. 

Here are some examples of where companies or other sources of information got it wrong:

• Medicinal Herb Info: Talks about Centaurium, but lists bluet and bluebottle as alternative common names, but those two names are only used in Centaurea.
• Specialty Herb Store: Same problem as above, lists common names only present in Centaurea for the medicinal Centaurium plant.  

Post updated 28 January 2014 with information provided by MF.