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
1856, Philodendron cordatum (cor-DAT-um) is not a synonym for either Philodendron
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.
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.
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 scientific 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
was published in 1857.
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.
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 where 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.
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.
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 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.
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
to 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 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 collects 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.
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 region 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.
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
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.
cordatum produces one to three inflorescences per floral sympodium
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
pinkish red to red on the outer surface once anthesis is complete.
The spadices typically measure 15 to18 cm in length.
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
the scientific information for Philodendron cordatum
Kunth on TROPICOS (a service of the Missouri Botanical Garden)
including enlargeable photos here:
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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