Quite often Philodendron species just don't match the "expected" description of the genus.  If you read many of the posts on various garden websites you'll find numerous discussions which will lead you to believe all Philodendron sp. are small vines which trail out of a pot on a kitchen or bathroom counter. Sorry, but this one won't fit! 

 

In early 2007 Dutch naturalist Joep Moonen (pronounced yupe), who takes adventurers into the rain forests of French Guiana and Suriname in the northeastern portion of South America, sent me an interesting small Philodendron specimen along with the legal permits.  That specimen had a single small leaf which was quite thick (see the original plant at the left and in the photo below right).  Information regarding the name on the tag, Philodendron melinonii (mel-i-no-NEE-eye), was sparse!  I found a total of two small paragraphs in one of Dr. Tom Croat's journals.  Almost nothing else.  I was able to learn P. melinonii was found in the rain forests of French Guiana, Suriname, Venezuela, and Northern Brazil.  And, according to TROPICOS which is a service of the Missouri Botanical Garden, the plant was identified to science in 1874.  So it has been known to scientists for a long time.  But apparently, collectors have not picked up the species as a commonly collected specimen.  Although our specimen is still quite small, from personal observation, it is also apparent the leaf blades will be heavily coriaceous (leathery) when grown.

Philodendron melinonii is both terrestrial and epiphytic.  An epiphytic species is one capable of growing on the branch of a tree or climbing a tree in to better collect sunlight.  In nature the species Philodendron melinonii is found growing high in the canopy perched out on the limb of a tree.  The undersides of the juvenile leaf blades of the species were reddish in color which morph into a matte green as the species matures.  Dr. Croat pointed out in one of his notes,  "Philodendron melinonii Brongn. ex Regel, a distinctive species with cordate blades and placed by Krause in P. sect. Macrolonchium, is in my opinion, not related to either of the sections with lobed leaves."  A cordate blade is one that is more or less "heart shaped".

 

Since the Philodendron species is epiphytic, but also grows as a terrestrial plant, the question arose "just how large will this Philodendron grow".  How large would our small specimen eventually become?  I set out to gather information from a group of collectors and researchers who are often a great source of information on any almost aroid species, the people who contribute information and discuss aroid species on Aroid l (that's an L).  This plant can become very large!

 

Jonathan Ertelt who is an educator, tropical plant specialist and university greenhouse manager in Tennessee, directed me to one of the first really good sources of information on this species when he sent this note, "If you have the back issues of Aroideana, or can get someone with easy scanning capabilities to scan it, Tom talks about P. melinonii in Aroideana 9 (1-4), 1986, pp 130-132."  Jonathan was referring to botanist Dr. Tom Croat of the Missouri Botanical Garden in St. Louis.  Dr. Croat often provides information to the Aroid l group and assists with my searches for plant information.  But Tom had just left for a two month collecting and research trip to Ecuador.  I immediately dug out the issue of Aroideana to which Jonathan had referred.  Aroideana is the annual journal of the International Aroid Society and is included in your membership in the society along with the quarterly newsletter.  If you are not a member of the IAS, a link with information on how to join can be found at the bottom of this page, or the top of the homepage of this website.  Volume 9 is one of the richest issues ever printed since it contains a detailed article by Dr. Croat entitled "The Araceae of Venezuela".  That issue is one every aroid collector/grower should possess.  A link to information on how to  a copy is also at the end of this article.

 

Dr. Croat pointed out the aroid is relatively common in northern South America.  It is typically found at elevations above 1000 meters (3000 feet) in Venezuela but at much lower elevations, (approximately 250 meters, or 800 feet) in French Guiana.  Near the Manaus area of Brazil, Dr. Croat found the species to be extremely common.  Common to the point of being a dominant epiphytic species.  Tom reported he suspected the species to be much more widespread than previously reported in other scientific information.  Of interest to this collector, despite the fact it is common in the northern portions of South America, it still has apparently not garnered a great deal of interest among North American Philodendron collectors.  It is quite rare within private collections.

At approximately the same time as Jonathan responded, I received a note from noted aroid collector and author Leland Miyano in Hawaii.  Leland worked closely with highly respected Brazilian plant collector, author and artist Roberto Burle Marx (now deceased).  Leland commented, "I grow a good number of these plants and the following will give you a better idea of the appearance and my cultural practices.  Philodendron melinonii is common in the Manaus area of Brazil....Roberto had several expeditions to the Amazon and my plants are from his collections.  I have seen slight variations regarding the color of the petioles, but am unsure if this is a genetic or cultural trait in all instances.  I have the typical reddish petiole form but in shade, these will be green.   Regarding ultimate size, my plants have petioles about 28 inches long.  The leaf blades are also about 28 inches long by about 20 inches wide.   A large plant can be about 8 feet in diameter...larger if a cluster of plants is grown as they pup regularly in bright light. 

 

I grow them as both epiphytes and terrestrials, although the normal condition in habitat is as epiphytes.  The stems are covered with a dense fiber, and to separate pups is usually best done while the plants are small...one must dig down through this fiber to find the point of origin of the pups.  Culturally, this plant is easy as long as the light levels are not too low.  Large plants can easily weigh 75 pounds or more, but the rosettes are compact and the plants are well worth the space.  Growth rate is moderate in strong, but not burning sun.  The petioles get a deeper color as the light levels increase."

 

Jonathan also made available this interesting observation/information regarding P. melinonii, "I was able to find a map of an epiphyte-covered tree that I built and planted at UNC Charlotte, and it was P. melinonii that I had growing almost like a crown from the top of this tree. Wonderfully large leaves, although not gigantic by aroid standards, and with very short internodes so it was almost more like a huge rosette up there. Given the side of a tree to climb up, I'm sure it would have. But it was fine as it was too, and then started throwing those great adventitious roots out and then down the sides of the tree it was very effective."

 

And noted Miami aroid collector Ron Weeks provided this observation, "Since the first day I saw it Philodendron melinonii has been one of my favorite plants. I have five very large specimens. The two largest have spreads over eight feet. I have good photos of the plant, inflorescence, seed and seedlings."  Ron advised he will soon be posting new photos on the International Aroid Society website http://www.aroid.org/

 

The leaves, petioles and spread of Philodendron melinonii can become quite large.  From Leland's description alone (also compare the size of Enid's arm and body to the leaf in her photo above, left), both the petiole and leaf can each reach at least 28 inches in length (approximately 70cm).  The ruler in Leland's photo is four feet long!  And as was stated by both Leland and Ron, a fully grown specimen can reach approximately eight feet in diameter (2.5 meters).  And remember, this spectacular Philodendron commonly grows up on the branch of a rain forest tree! 

 

In a separate email message, Leland provided this additional information regarding Philodendron melinonii, "I think a good characteristic to point out is that the abaxial, or lower surface of the leaf blades, exhibit prominent veins. The adaxial or upper surface is smooth in comparison. Also, the color of the undersides of the leaves changes with maturity. There is a reddish tint to the undersides of the blades of immature plants, but this disappears in older specimens. One of the attractive features of this plant is the point of attachment of the leaf blade and petiole...it is really distinct with the reddish color of the petiole defining the limit of the petiole. There are also scattered dark spots on the petioles and leaf blades.  I am in agreement with Ron Weeks...this plant is one of my favorites too."
 

Dr. Croat pointed out in his Aroideana article the petioles of Philodendron melinonii were somewhat spongy to the touch and if cut the cross section could be observed to be shaped like a capital letter "D" or sunken on the upper surface to resemble the capital letter "C".  Despite common misconceptions, the petiole is not the "stem" which is the term commonly incorrectly used by collectors. The petiole is the stalk which connects the leaf blade to the stem which is at the base of the plant.  The C shape is described by a botanist as being sulcate.  The term sulcate may indicate either a single channel running down the axis of the petiole or a series of tiny parallel groves running down the axis.  The petioles are near equal size to the leaf blade as can be observed in Leland's photos.  

 

Instead of supporting the leaf blades the stem is the base or axis of the plant.  The stem of any Philodendron has nodes at fairly regular intervals and the petioles as well as the roots and peduncle which supports an inflorescence grow from those nodes along the stem's length.  The stem segments which separate the nodes are known as internodes. 

When a new petiole grows from a node it is surrounded by a cataphyll which is a bract-like modified leaf that surrounds and protects the new leaf as it develops.  A cataphyll is any foliar organ that has no differentiation between the petiole and the blade.  The cataphyll is the singular most important identifying characteristic of an aroid due to its very unique shape.  Once the cataphylls of Philodendron melinonii dry they remain on the plant as persistent fibers.

All Philodendron species are members of the larger plant family known as Araceae, commonly called aroids.  An aroid is a plant that reproduces via the production of an inflorescence which in aroids is known to science as a spathe and spadix.  Some believe the spathe is a "flower" which is incorrect. The spathe is simply a modified leaf appearing to be appear as a hood and is sometimes shaped like a tube.  When an aroid is referred to as "flowering" the reference is to the very small flowers found on the spadix and has nothing to do with the spathe.   Within the inflorescence there are extremely small flowers found on the spadix during anthesis (sexual reproduction).  The spadix is found at the center of the inflorescence.  When ready to reproduce, the spadix produces both male, female and sterile flowers and if the female flowers are pollinated with pollen brought by an appropriate insect (normally a beetle) from another plant which is at male anthesis they will produce berries containing seeds.  The female flowers are hidden from view inside the floral chamber at the bottom of the spathe in Philodendron species.  Due to natural variation within the species Philodendron melinonii the spathe tube is white on the inside but may be greenish aging to reddish on the exterior of the spathe tube.

 

Typically, the seeds of epiphytic species are distributed by birds or rain forest animals that eat the berries containing seeds produced on a pollinated spadix.  In the case of Philodendron melinonii, Joep indicated in a recent email, insects also contribute to the species' distribution.  Joep wrote he had observed photographs of, "ants carrying the seeds of Philodendron melinonii away near Saut Mapao on the Approuague river in French Guiana".  He commented further regarding the species in an email to Julius Boos, "Philodendron melinonii is a real epiphyte. The seed is likely dropped at a branch or tree trunk and develops right there to adult plants. Fat petioles (some times red in color), yellowish fruits that are carried away by ants."  Regardless of how it gets from from tree to tree in the wild, Philodendron melinonii is going to make one fabulous centerpiece in the collection once it matures.

 

My thanks to Enid Offolter of Natural Selections Exotics in Fort Lauderdale for the use of her photo as well as those of Leland Miyano and Brian Williams.  Much thanks to all those who responded with valuable information via Aroid l.  Others also responded with photos and I regret space prevents the use of all that were provided.  And my sincere thanks to my friend Joep Moonen who provided the specimen.

 

Philodendron species are known to be highly variable and not every leaf of every specimen will always appear the same.  This link explains in non-technical language natural variation and morphogenesis within aroids and other species.
 Click here.