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In depth information on how to grow Philodendron species, Click this Link

Within our collection we have many species of Philodendron.  If you are seeking other photos, click this link

The common name "Philodendron cordatum Hort." is not the same plant as the species known to science as
Philodendron cordatum Kunth.  "Hort." indicates the name is a horticultural common name and is not scientific.


Click here to see Philodendron hederaceum, P scandens, P oxycardium, P. micans.

Philodendron cordatum
Kunth 

Philodendron cordatum, Photo John Criswick

Philodendron cordatum Kunth
Synonym: Arum cordatum
 

Common names: Philodendron Angra dos Reis, Heart Leaf Philodendron,
 

Published to science in 1856, Philodendron cordatum (cor-DAT-um) is not a synonym for either Philodendron scandens or Philodendron oxycardium  The species Philodendron cordatum is not similar to either.  Despite the claims of many websites Philodendron cordatum is not a commonly kept house plant.  

Philodendron cordatum photographed at the Marie Selby Botanical Gardens, Sarasota, FL.  Photo Copyright 2008, Phil Nelson for Selby Gardens.The common name "Philodendron cordatum Hort." is used incorrectly by plant collectors for the species known to science as Philodendron hederaceum but is not a scientific name nor a synonym relating to that species.  Philodendron hederaceum is common to much of Mexico, all of Central America, almost all of tropical South America as well as portions of the Caribbean but is not related to Philodendron cordatum Kunth except by genus. 

Philodendron hederaceum is likely the most commonly grown house plant in most of the civilized world and is one of the most variable of all Philodendron species taking on many leaf forms, textures and colors.   Variations of Philodendron hederaceum are commonly called the "heart leaf Philodendron".  The term "heart leaf" comes from the shape of the leaves which is known as cordate.  A cordate leaf is simply one that is shaped like a heart and the species Philodendron cordatum Kunth also possesses a cordate leaf.

Found in one specific region along southeastern Brazil's coast, Philodendron cordatum is endemic or exclusively found only in the coastal regions near Rio de Janeiro and São Paulo.  
P. cordatum is primarily an epiphyte (ep-a-FIT) which indicates it is a natural tree climber but the species also grows across the ground where it is observed growing as an epilithic (epi-LITH-ic) vine.   My friend and invertebrate ecologist/ taxonomist Christopher Rogers wrote, "I have Philodendron hederaceum in my collection and have seen both P. hederaceum and Philodendron cordatum in Brazil.   P. cordatum is far bigger than hederaceum and the purple spotting is really lovely.  I have only seen P. cordatum growing along the ground in rocky terrain while P. hederaceum was always up in the trees with lots of hanging vines."  Epilithic plants grow attached to stone.

Aroid expert Leland Miyano explains about the growth habit as well as the area where Philodendron cordatum grows in nature,  "Near the town of Parati and Ilha Grande in the Brazilian state of Rio de Janeiro the granite coastlines have Philodendron cordatum as rupicolous or saxicolous creepers growing on the enormous granite boulders that line the shores. These specimens may have fallen from trees or started on the humus that accumulates on the boulders. They often form a sort of border between the shoreline and the forests"   The coastal town of Parati is west and slightly southwest of Rio de Janeiro.  Rupicolous (r-PIK-lus) and saxicolous (sak-SIK-lus) plants are species that grow either on or among stones. 

Many websites including a few associated with universities and the U.S. government indicate Philodendron cordatum is a synonym for Philodendron scandens subsp. oxycardium.  Scientifically that is inaccurate since neither the published Philodendron hederacerum known as Philodendron scandens, Philodendron micans, Philodendron oxycardium, Photo Copyright 2009, Steve Lucas, www.ExoticRainforest.comscientific description of either of these plants nor any recognized scientific data base indicates these species are one and the same.   In science a synonym is a species which has been previously published and described to science but was again published using another name.  This "myth" appears to have been advanced in horticultural circles in the past and has persisted as "fact" with plant collectors as well as some authoritative sources.  "Philodendron cordatum Hort." is nothing more than a common name with no scientific significance.

Philodendron scandens (scan-DENS) was published in 1853 and Philodendron oxycardium (oxy-CAR-deum) was published in 1857Both are common house plants and each has was sunk into synonymy in 1856 under Philodendron hederaceum (hay-day-RA-see-oom).  Philodendron hederaceum was described and published much earlier in 1829.

The specimen of Philodendron cordatum growing at the Marie Selby Botanical Gardens in Sarasota, FL shown at the top right of this page was grown from seed collected from a private nursery in Brazil during the early 1970's.  The specimen was originally tagged "P. Angra dos Reis" due to the location where it is commonly seen in nature and was set out at the garden in 1978 where it has survived an extreme low temperature of 4.44 C (24 F) in 1983.  The leaf blades of that specimen measure 38 to 61 cm (15 to 24 inches) in length.   Phil Nelson's photo was provided by Harry Luther of the Marie Selby Garden.

Once shown a photo of a juvenile specimen in our collection Hawaiian aroid expert Leland Miyano explains how the common name Angra dos Reis  originated, "Philodendron 'Angra dos Reis is Philodendron cordatum Kunth.  Your plant is still a juvenile, so it resembles a few things. Philodendron cordatum is a wonderful plant and can take the cold of Sarasota Philodendron cordatum, venation, midrib, basal veins, basal ribs, primary lateral leaf veins, forelobes, Photo Copyright 2009, Steve Lucas, www.ExoticRainforest.comwhere I saw it growing happily outdoors.  I saw large groups of these at Angra dos Reis in the state of Rio de Janeiro which is a bay town with granite boulder coastlines.  This species grows just back of the high tide lines and into the forests."   The name Angra dos Reis means "King’s Cove" in Portuguese and is a city approximately 150 km (60 miles) southwest  of the city of Rio de Janeiro, Brazil.   Famous for its coastline on the Bay of Ilha Grande with its 365 islands the name Philodendron Angra dos Reis appears to have been used in a seed list from the late 60's early 70's.

The leaves of Philodendron cordatum are a medium green and become deciduous.   A deciduous plant is one that often looses its leaf blades during periods of dryness.  The blades of P. cordatum are glossy on the blade's top known as the adaxial surface as well as subcoriaceous to moderately coriaceous in thickness.  Coriaceous indicates the blades are leathery to the touch while subcoriaceous indicates they are just less than leathery.  The lower or abaxial leaf surface is matte.  The leaf blades may be moderately bi-colorous or two colored.  The blades cordate as well as ovate (slightly oval) to broadly ovate at the apex.  The base of the blade is cordate with an acute lower tip.  The term acute indicates pointed while cordate indicates heart shaped.  The leaf blades may grow as large as 40 to 65 cm (15.75 to 25.5 inches).

Aroids and other plant species have veins sometimes known as nerves on each leaf blade. The venation is distinct in some species but far less so obvious in others.  Each vein type has a specific name for purposes of being specifically described in to science since specific characterizes are important to the determination of any species..  The most prominent veins on Philodendron cordatum are the midrib, basal ribs, and primary lateral leaf veins. The interprimary or secondary veins are less obvious as are the tertiary or minor veins.  There should be 5 to 7 primary lateral veins on each side of the midrib at the center of each leaf. 

The midrib as well as basal ribs of Philodendron cordatum possess nectaries that appear as purple/reddish splotches having the color of reddish wine.  In botany this coloration is known as vinaceous (as in the color of purple grapes) and these nectaries sometimes exude a sweet sugary extra-floral liquid.   Although the purple splotches can be observed on other parts of the plant the color alone does not always indicate a nectary is involved.

Nectar is often produced as a part of pollination but plant structures that produce nectar for reasons other than attracting a pollinating insect are known "extra-floral".  These extra-floral nectaries have been observed in at least 2000 species in as many as 64 plant families and are not uncommon in Araceae.  The nectaries can be found on portions of the plant that are not associated with flowers or reproduction. 

Flowers commonly produce nectar as a reproductive attractant to cause a pollinator to visit.  The accepted theory for non-reproductive nectaries includes assisting the plant to maintain a balance between the water and sugars inside the xylem Philodendron cordatum extra floral nectaries, Photo Copyright 2009, Steve Lucas, www.ExoticRainforest.comand possibly as a defensive mechanism.  The xylem is a tissue inside the stem and petiole that conducts water along with sugars and mineral salts from the roots to all parts of the plant.

Extra-floral nectaries often attract ants and the ants in turn appear to protect vulnerable leaves as well as tempting plant parts from animals that graze.   Many plants including Philodendron species are known as myrmecophytes or "ant plants".  A myrmecophyte (myr-MECO-fit) is a plant that lives in association with a colony of ants and possesses specialized organs to entice the ants to build a colony around their stems (base of the plant).  The plant specimen then obtains nutrients from the nest as well as aeration of the soil which allows the roots to grow more freely.  

The aggressive nature of the ants towards any intruder appears to protect the plant from other animals or insects who would eat its parts.   The subject of non-reproductive sugars used as an insect attractant is complex and the relationships between individual plant species and a variety of insects is not well understood.

The posterior or forelobes contain three to six basal ribs per side.  The major veins are flat to only slightly raised and are paler in color on the upper surface.  The same veins are convex (raised) on the lower or abaxial surface.  The minor veins also visible. 

Although commonly called a "stem" the stalks that support the leaves are known as petioles.  The petiole connects the lamina of the leaf blade to the stem at the petiole's base.  Petioles grow from a bud on the stem and transfer water along with nutrients to the leaves via a unique form of hydraulic pressure.  Rather than being pushed upwards the water is drawn Philodendron cordatum petiole, Photo Copyright 2009, Steve Lucas, www.ExoticRainforest.comto the blade by evaporation into the atmosphere though the upper blade surface.  The leaf blades absorb carbon dioxide in the air and convert it into oxygen for all living organisms to breathe. 

The petioles are marked with purple blotches as is the midrib and other portions of any mature specimen.  The petioles of Philodendron cordatum are weakly flattened as well as slightly spongy to the touch and typically measure between 55 to 61 cm (21.5  to 24 inches) on an adult specimen.  If examined closely a slight striation can be observed (photo, right, below).  Philodendron cordatum petiole, Photo Copyright 2009, Steve Lucas, www.ExoticRainforest.comStriation is simply lines running along the axis of the petiole.   

The cataphylls of Philodendron cordatum are double keeled (two ribbed) as well as a medium green in color.  A cataphyll protects the newly emerging leaves as they form and are a bract-like modified leaves that surround any new blade as it first emerges from the bud.   A double ribbed cataphyll is known as a prophyll and is a specially modified cataphyll with two ribs or "keels" running along the posterior surface.   The cataphylls of P. cordatum are deciduous and fall from the plant once the blade develops.   The cataphyll/prophyll of a mature specimen measures approximately 29 to 40 cm (11.4 to 15.75) and is narrowly triangular in shape.  As the cataphyll matures it changes from green to yellowish-green before finally turning rusty red.  The cataphyll is also covered with vinaceous extra-floral nectaries. 

The stem of any Philodendron is the base or central axis of the plant and is the plant's main support.  Petioles, buds, cataphylls, roots and the peduncles which support the inflorescences of the specimen grow from the stem.  The stem Philodendron cordatum cataphyll, Photo Copyright 2009, Steve Lucas, www.ExoticRainforest.comcollects and stores water collected by the roots which grow from the nodes at regular intervals along the stem's length.  The stem segments which separate the nodes are known as the internodes.    Depending on the age of the specimen the internodes are typically 6 to 8 cm (2.3 to 3 inches) long but may be shorter in young plants.  The internodes and are light brown in color. The stem of P. cordatum is green becoming grayish as the plant matures. 

Philodendron species are members of the larger plant family Araceae (uh-RAY-see ee) commonly known as aroids.  An aroid is a plant that reproduces via the production of an inflorescence known as a spathe and spadix. Although many growers believe the spathe is a "flower" the spathe is simply a specially modified leaf whose purpose is to protect the spadix at its center. 

The spathe does not qualify as a flower since it possesses no sexual parts.  All flowers have pistils, stigmas ,ovaries, ovules, stamens and anthers.  Without those sexual parts a flower has no way to be fertilized or reproduce.  A spathe possesses none of these parts but all can be observed on the spadix at its center.  The spadix appears as a spike on a thickened fleshy axis which does in fact produce tiny flowers. 

When ready to reproduce the spadix of a Philodendron produces male, female and sterile flowers which are cleverly divided by Mother nature into separated zones in order to prevent self pollination.  The female flowers are hidden inside a Philodendron cordatum juvenile, Photo Copyright 2008, Steve Lucas, www.ExoticRainforest.comregion at the bottom of the spathe known as the "floral chamber" with the sterile male flowers secreted just above.  The fertile male flowers which produce pollen are in another region which is exposed on the visible portion of the spadix well above the floral chamber.  The purpose of the sterile flowers is to produce a perfume-like substance known as a pheromone which attracts the appropriate pollinating insects but it also serves as a source of protein for the visiting insect pollinators by producing lipids.

The sterile male flowers begin to entice pollinators which are normally small beetles from the genus Cyclocephala by sending out their pheromones on the breeze which floats through the forest.  Those beetles gather pollen from another member of the same Philodendron genus and bring it to the female flowers while being enticed to fly to the source of warmth and food in the coolness of the rain forest evening.  The beetles can "see" the inflorescence since it produces both a scent and a "glow" in the form of infrared heat which is suspected to be visible to a special receptor on the end of their antennae. 

Philodendron species produce their female flowers on the first evening of anthesis and they are no longer receptive by the time the male flowers begin to produce pollen on the second (possibly the third) evening.  This is another of nature's ingenious ways to keep her species pure.  If the female flowers are pollinated with pollen of another plant of the same species which is already at male anthesis and are carried by an appropriate beetle from the second specimen they may in time produce berries containing seeds.   No photo of the inflorescence or a scientific record of the color of the berries produced by Philodendron cordatum can be located.

If you are interested in a more detailed account of how aroids reproduce please visit this link:  Natural and artificial pollination in aroids.

Philodendron cordatum stem, roots and petiole, Photo Copyright 2009, Steve Lucas, www.ExoticRainforest.comPhilodendron cordatum produces one to three inflorescences per floral sympodium (axil).  The inflorescences are supported by a stalk known as a peduncle which can measure 3 to 9 cm (1.2 to 3.55 inches) in length.  The spathes typically measure 17 to 21 cm (6.7 to 8.25 inches) long and are slightly constricted at the center.  The outer portion of the spathe blade is green to a greenish cream color and also exhibits vinaceous grooves once immature.  The spathe becomes cream colored on both the inner and outer surfaces once the inflorescence approaches anthesis finally turning pinkish red to red on the outer surface once anthesis is complete.   The spadices typically measure 15 to18 cm in length. 

Philodendron species are known to be highly variable and not every leaf of every specimen will always appear the same.  As can be seen in the photos on this page, Philodendron species go through morphogenesis (ontogeny) as they mature.  This link explains in non-technical language natural variation and morphogenesis within aroid and other species.   Click here.

 

My thanks to Leland Miyano for his expert input as well as John Criswick and Phil Nelson for the use of their photos.  Phil Nelson is associated with the Marie Selby Botanical Gardens in Sarasota, FL.
 

The scientific data for this article was extracted from the published field notes of Dr. Thomas B. Croat Ph.D., P.A. Schulze Curator of Botany at the Missouri Botanical Garden in St. Louis, MO.  as well as from the Royal Botanic Kew's CATE Araceae.  You can view the scientific information for Philodendron cordatum Kunth on TROPICOS (a service of the Missouri Botanical Garden) including enlargeable photos here:  http://www.tropicos.org/Name/2103189

Cate Araceae can be found here:

 
http://www.cate-araceae.org/index.do;jsessionid=96982249A0181F1EB1E74E6CEB9841D4

Philodendron cordatum does not match the scientific description of either Philodendron scandens, Philodendron oxycardium nor the accepted species name Philodendron hederaceum You can read our synopsis for Philodendron hederaceum (Philodendron scandens, Philodendron oxycardium) here.

 


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