Philodendron hederaceum (Jacq.) Schott

Synoynms:

 Common Names: Heart Leaf Philodendron, Velvet Philodendron, Velvet Leaf Philodendron.
Heart Philodendron, Sweetheart plant, Philodendron 'Brazil', Philodendron 'Brasil', Velour Philodendron

What is the true name of this plant?
A 180 year old discussion that is still argued by plant collectors.

 

The discussion you are about to read regarding the variability of Philodendron hederaceum (along with its numerous scientific names) has been going on for almost 180 years.  Despite the claim that botanists keep changing the name of this species, the name was established many years ago.  The names Philodendron micans, Philodendron scandens, Philodendron miduhoi, Philodendron oxycardium and others are simply synonyms of Philodendron hederaceum.  Although those names are commonly used by plant collectors, to an aroid scientist they are no longer accepted.

 

An aroid, the species Philodendron hederaceum was described to science in 1829 so the discussion regarding the correct name is not new.  Within aroid species there is change.  Part is during the life of a single plant and is known as  ontogeny,  or changes observed as that plant grows.   We often call those changes morphogenesis since the changes are seen as the grows from juvenile to adult.  But the other change, or variation within a species, is not sudden.  It occurs over a very long term which can easily be eons.  And that long term variation has created a great deal of controversy and confusion among collectors.

 

Philodendron hederaceum is widespread in the Caribbean as well as Mexico,  all of Central and most of South America.  In the Caribbean It occurs on the islands of Martinique south to Trinidad.  It can be observed at sea level to 1200 meters but possibly as high as 1500 meters (3,900 to 4,900 feet) in elevation.  In South America it extends from as far south as Los Ríos province near the coast of Ecuador up through Colombia, Venezuela, the Guianas, Brazil, Peru, and Bolivia. 

ut species
P. hederaceum is frequently collected, it is often misunderstood and misnamed Philodendron species in the rain forest.  Although virtually all private collectors consider the species to be small as well as suitable for growing in the kitchen or bath it can grow much larger than most ever expect and is highly variable.  So variable the plant has incorrectly been granted a number of scientific names!  Most collectors consider a few of those names such as Philodendron micans or Philodendron scandens to be the ideal "house plant".  They also consider them all to be totally different species.  But to a botanist they are one and the same plant,  

 

Although many juvenile specimens have a deep burgundy on the underside of the leaf, other specimens are only green!   Within a few seasons of growth you can watch the plant change shape, texture and color, especially if allowed to climb.  It is not uncommon for a plant to loose the reddish underside and have the blade change color.  Philodendron hederaceum can also loose the velutinous (velvet) texture and appearance.  Variation is common in all aroid species.

 

Confusing?  Perhaps we can help you to understand the dilemma brought upon botanical scientists all by themselves.

 

Aroids are distinguished since they produce a spathe and spadix in to produce seeds.  You have almost certainly seen a spathe if you have ever grown a "Peace Lily"  (Spathiphyllum).  Those white "flowers" on the Peace Lily are not "flowers" at all!  Instead, they compose an inflorescence and the "flower" is the spathe which protects the post like portion at the center known as the spadix.  The spadix is where pollination occurs and seeds are produced. 

 

The true flowers, both male and female, grow upon the spadix and if pollinated by an appropriate insect the female flowers will produce berries which contain seeds.  If a bird or other animal eats the berry and drops a seed in its droppings, a new plant may form.  Those seeds often end up on the branch of a tree.  As a result, Philodendron hederaceum is known to science as a hemiepiphytic vine.  Hemiepiphytes are species that are capable of beginning life on a tree branch or they may begin as a seed dropped on the ground which then proceeds to climb.   They do not need soil to survive although as collectors, we always grow them in soil. 

 

For information on the pollination and reproduction of aroids click this link:  http://www.exoticrainforest.com/Natural%20and%20artificial%20pollination%20in%20aroids.html

 

In the case of Philodendron hederaceum (a/k/a P. scandens, P. oxycardium, P. micans, Philodendron Brazil, or Philodendron Brasil) they often grow very high in the trees and trail pendently towards the jungle floor as a hanging vine.  Technically the species is known as a scandent climbing vine.  A scandent plant is one that grows with the blades close to the host tree.

 

The leaf blades of Philodendron hederaceum are frequently velutinous (velvety) in appearance but may loose that velvet texture.  Frequently the undersides are tinged with a red or a purplish color which may also be lost as the plant morphs.  The leaf blades may be weakly glossy, sometimes matte but normally a pale to medium green.  In the case of a cultivar being sold as Philodendron 'Brasil' (or 'Brazil') the blades of the juvenile plant are yellow and pale to deep green with some leaves exhibiting a mixture of both colors..   U.S. law allows anyone who discovers a unique natural cultivar of any species may give that plant a name (i.e. Philodendron 'Brasil') and legally claim exclusive sales rights to that cultivar.  In Philodendron 'Brasil' the undersides have no distinctive color other than those similar to the top of the leaf blade.   Although many collects believe Philodendron 'Brasil' is a unique species if you look at the second photo of the plant (right) you can easily see as the plant emerges from the juvenile form the multicolored leaves as well as the yellow-green leaves are lost and begin to turn dark green as a part of natural plant variation and the morphogenesis into their adult form.  Keep in mind Philodendron 'Brasil' is nothing more than a natural variation of Philodendron hederaceum and not a unique scientific species.

The leaves of Philodendron hederaceum may be broadly ovate (heart shaped) as well as  subcoriaceous to coriaceous.  A coriaceous leaf is one that is leathery to the touch which would leave a subcoriaceous blade to be just less than leathery when felt.  But often, especially in juvenile leaves, the blade is quite thin and that is what you are almost certainly growing:  a juvenile plant! 

The adult leaves can range in size to approximately 50cm (19 inches) in length!  Few "house plant" growers will ever see a leaf of Philodendron hederaceum with blades that size unless you venture into the rain forests of Central and South America.  In the forest, the blades often measure 11 to 40cm  but possibly up to 50 centimeters (4 to 19.5 inches) long and 8 to 34 centimeters (3.25 to 13.33 inches) wide.   The botanical name for the stalk-like support for any leaf is the petiole, not the stem.

 

Now, as you can quickly see in the photographs on this page, this species does not always appear the same.  How is that possible?  Within aroids variation is common,  Think of it like human faces.  You know many people but those people don't all look alike.  They all have different body sizes, different shoe sizes, different hair color, different tones of skin, and often very distinctive facial features which we just accept as human or racial differences.  That is the same as variation in the world of plants! 

 

Dr. Thomas B. Croat Ph.D., P.A. Schulze Curator of Botany at the Missouri Botanical Garden in St. Louis once explained that if you were to make collections of this species throughout its natural range, which is large, you would find countless slight variations.  But all those hundreds, possibly thousands of variations, have never been granted their own exclusive name.  Only a select few which to a botanist somehow appeared distinctive were granted a name.  But the names that have stuck are well entrenched in the minds of plant collectors.  As Dr. Croat explained, "It is simply the nature of evolution."

 

There is only a single species of human being known as Homo sapiens with many faces and body shapes.  Within the world of Philodendron hederaceum there are many "faces" and shapes but only one species.  The differences are only variation and/or morphogenesis.  It was perhaps only the botanists of previous eras who often granted different scientific names to a large number of plants that did not "appear" alike.  But when upon careful examination of each one of those "species" they all have the same scientific features, especially the sexual features found within the spathe and spadix.  And that forces a well studied botanist such as Dr. Croat to disregard all the newer names and revert to the basionym name (base species name) which is Philodendron hederaceum.  That was the first valid name granted to this species. 

 

The reason?  Within the rules of botany it is established the first name ever granted a species becomes the basionym and all attempts to rename that plant simply become synonyms of the basionym once any errors as to the genus are discovered.   As a result, all the commonly used names known by collectors are now simply synonyms of the base species and are no longer valid within science.  They are still used, but technically no longer the prime species' name, nor valid to an aroid botanist. 

Before I attempt to explain about the neme controversy you should understand the botanical author of this species,  (Jacq.) Schott, is two people.  Dr. Croat explains, "What this says is that Jacquin, an Austrian botanist described the species and Schott later put the species into a newer, more modern genus.  When Linnaeus started describing aroids there were only 4 genera so everything had to fit there. Jacquin’s full name was Baron Nicolas Josef von Jacquin (1727-1817).  His father was Baron Josef Franz von Jacquin.  He was also a botanist but not so famous or productive. The Schott in your name was Heinrich Wilhelm Schott, the so-called grandfather of Araceae owing to the fact that he described most of the existing genera."  Now, the explanation of how this controversy began and has continued for years.
 

Botanist Heinrich Wilhelm Schott (1794 to 1865) understood the problem of variation within this species.  He had already transferred the original genus (Arum hederaceum) to the genus Philodendron in 1829.  in 1856 Schott also placed Philodendron hederaceum into synonymy under his newly described Philodendron jacquinii.  However, he included P. hederaceum in his grex Macrobelium while placing other synonyms of Philodendron hederaceum within grex Solenosterigma.  The names transferred along with the first were Philodendron scandens, P. oxycardium, P. micans and others.  And the discussion on the correct scientific name for this species began in 1829.

In 1899 botanist Gustav Heinrich Adolf Engler (1844 to 1930) treated the species science now accepts as Philodendron hederaceum as four distinct species which included Philodendron scandens, P. oxycardium, P. micans and a name no longer used.  And the debate was well underway.  This quote can be found in a treatment on this subject by Dr. Croat, "Both Engler and Krause erred in treating Arum hederaceum Jacq. as a questionable synonym of P. hoffmannii (= P. jacquinii), citing Jacquin's (1763) t. 152 as the type.  Despite the confusion by Engler and Krause, Standley and Steyermark (1958b), in the Flora of Guatemala, correctly dealt with the taxonomy of P. hederaceum, citing P. scandens, P. oxycardium and P. miduhoi in synonymy there under. Their treatment of P. jacquinii was incorrect, since they cited that name under the later synonym P. hoffmannii Schott (1858).  In this regard they followed Krause (1913).  Thus, despite the confusion by Engler and by Krause, the nomenclature of these species was essentially rectified as early as 1958, to the species as P. oxycardium or P. cordatum hort. (non Vell.)."  

 

Despite that confusion, botanist Julian Alfred Steyermark (1909 to 1988) correctly dealt with the taxonomy of Philodendron hederaceum in 1958 citing P. scandens, P. oxycardium and P. miduhoi as synonyms of Philodendron hederaceum.   But then in 1963 botanist George Bunting attempted again to grant a new name that is now clearly understood to simply be Philodendron hederaceum,  Other noted botanists have written opinions all along the way about the variation within the species Philodendron hederaceum and it is now considered a settled argument with Philodendron hederaceum being the base name (basionym).  The problem of incorrect multiple names for a single species has long been debated  and understood.  Attempts were made to correct the problem beginning many years ago and is not something recently created. 

 

Still, it is confusing.  But collectors don't always like to accept botanical science.  Collectors appear to prefer a different name for anything that does not look alike.  Despite beliefs posted on the internet that botanists are perpetually toying with names and are "constantly changing" those names, the scientific fact is botanists are simply following the rules of botany as outlined by Linnaeus and no one has changed anything!  These botanical scientists are simply following those rules as defined for centuries. 

 

The "facial features" of a plant have nothing to do with the name of the species!  Aroids are simply variable.  The final determination of any species is based on the total characteristics of that plant including how it grows in nature, node spacing and the sexual features of the inflorescence as well as other characteristics.  Appearance of the leaf face simply does not apply as a part of any scientific discussion.

 

Here's another way to consider variation.  We know there are many races within our human species but only a single species which is Homo sapiens. With most, the only major difference is skin color or some facial feature such as the eyes.  But which race is the "basionym" or base species?  Oh would that get complicated and offensive if anyone were to claim the Negroid race, or the Anglo race, or the Asian race was the base species and all others needed a new name which science would immediately declare as  a "synonym". 

 

As a result we are happy to simply divide our species into races.  But we all also understand that none of those races have any major scientific difference when a doctor is called in to operate.  When a botanist determines there is no scientific difference in Philodendron oxycardium, Philodendron scandens, Philodendron miduhoi and Philodendron hederaceum we are left only to go back to the first name ever assigned and that name is Philodendron hederaceum. 

 

It doesn't work well for plant collectors but it works fine for science.  Collectors are the ones that perpetuate the confusion by using multiple names.  Botanists did not start a new trend nor change the name of anything!

 

You should be aware there are books written for plant collectors that have attempted to make a "scientific" explanation of the use of multiple scientific names.  But that attempt is nothing more than pseudo-science.  Two books, Tropica and Exotica by A. B. Graf have attempted to do just that.  In Tropica there is an attempt to justify the use of many of the names above and to divide them into some sort of guide to determine the "differences".  But Tropica  was never intended to be science.  Instead Mr. Graf started out to just bring the world of rare plant species to collectors.   Within Mr. Graf's texts there are many names that have no basis in science, someone simply made them up to sound scientific!  Some of those names contain the last names of a collector with a double i at the end and are not scientific  Ever hear of Philodendron wilsonii?  It is not a scientific species!  Many of the names Graf chose to use never had any standing in science and were never published in any scientific journal!  But his explanations do satisfy a need by collectors.   As a result of Mr. Graf,  I personally spent two years chasing "Philodendron mandaianum" and could never figure out why the name wasn't in a scientific text.   Mr. Graf was not a botanist, he was a horticulturist and plant collector who did a good thing by introducing many of us to unusual species.   But his books are known to be filled with errors.

 

Philodendron hederaceum is easily grown in very porous soil that drains quickly.  We use a mixture of moisture control soil, orchid bark, peat moss, and Perlite.  Do not attempt to keep the roots wet!  P. hederaceum will display best if given a totem to climb.  The taller the totem the larger the leaves can grow.  It should be kept in moderately bright light with high humidity.  As a result, attempting to grow one in a dark bathroom or living room with little light will eventually cause the plant not to flourish although it will benefit from the higher humidity within that room.  Remember, this species grows up in the rain forest canopy where it can easily gather light and the humidity is constantly high.  For short periods of time lower light levels should not harm the ultimate health of a specimen.   The brighter the light, the larger the leaves will grow.  The plant is easily reproduced by simply taking a cutting before any node on the vine.  Place at least two nodes in porous soil and keep it damp with moderately bright light.  Some people prefer to root in water but this plant does not naturally grow in water.  Rooting in soil with the addition of a commercial rooting hormone will speed the process.  Although nature uses no bottled "homeones", the soil is filled with nutrients returned to the earth by decomposing vegetation and that compost is used by when a tree falls in the forest so the epiphytes living on that tree can begin the rooting process again.  It ia aimply a form of natural fertilizer.

 

For more information regarding natural variation and morphogenesis (ontogeny), this link is written in non-technical language  Morphogenesis and natural variation

 

The scientific information within this text was taken directly from the published treatment of Philodendron hederaceum which was written by Dr. Tom Croat along with numerous email exchanges and visits.  If you'd like to read that treatment you can locate it here:  http://www.aroid.org/genera/philodendron/Philodendron/Solenosterigma/hederaceum.htm 

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