Some sources have tried to claim this species is a hybrid, however, both TROPICOS (Missouri Botanical Garden) and the International Plant Names Index indicate it is a recognized and published Brazilian species.  Philodendron stenolobum was described to science by Dr. Eduardo Gonçalves (gon-ZAL-vas), the very well known Brazilian botanical expert.

The plant has long wavy narrow leaves that average 2 to 3 feet (60cm to 90cm) in length and can be approximately 1 foot (30cm) wide in one of the collected variations.  P. stenolobum has glossy leaf surfaces and there are several varieties of the species sometimes offered for sale.  One (not the one shown in my photo) has much narrower and even more wavy leaf blades and another shows little resemblance to either (see below).   Yet, they are the same species, simply different forms.  Philodendron species, and especially hybrid forms, are known to be highly variable and not every leaf of every specimen will always appear the same.  This link explains in greater detail the scientific principle of natural variation and morphogenesis.  Click here.

This Philodendron is generally known to collectors as a self header and is thought by some not to be a climber.  Information from Leland Miyano in Hawaii will quickly destroy that theory!   Leland recently wrote, "Two of mine have at least 20 feet of trunk."  Leland then adds this note regarding specimens he personally collected in Brazil, "I have them growing up Ficus pseudopalma.   I have several different clones from several sites from Espirito Santo to Southern Bahia.  They have odd thorn-like projections on the aerial roots."  Leland states the trunk of his specimens is approximately 4.5 inches (11.5cm) thick. 
According to Dr. Gonçalves' technical description the plant is actually a hemiepiphyte (hem-a-EPA-fit).  That group of plants is epiphytic for one portion of its growth but becomes rooted in the soil during another stage.  A primary hemiepiphyte begins as an epiphyte (ep-a-FIT) growing on trees and later becomes rooted in soil, while a secondary hemiepiphyte begins life rooted in soil and later becomes an epiphytic plant form.  Dr. Gonçalves reports the plant is hemiepiphytic in forests but "occasionally" becomes terrestrial in open areas.  Since Dr. Gonçalves reports it is capable of growing without the support of a tree in open terrain this species would appear to be secondary. 

That terrestrial growth form in open areas has led the philodendron to be known by collectors as a "tree philodendron" that grows a thick "trunk" as it gets larger with a plant height (according to collectors) of 18" (46cm) to 4 feet (120cm).  Florida plant collector Russ Hammer has reported in a personal email his self supporting specimen was taller than 4 feet (120cm).  According to Dr. Gonçalves' published report and the information regarding Leland's plants in Hawaii the species is certainly not strictly a "tree" philodendron as some reports have claimed! 

Philodendron stenolobum  is sometimes sold as P. willamsii in the plant trade and was thought by some to be a narrow leaf form of P. williamsii.  These species are not one and the same.  The true Philodendron williamsii has shorter, broader leaves and is not as attractive a plant as P. stenolobum.  There are distinct differences in the two species.  Many forms sold as P. williamsii (including the specimen shown to the right) are simply variations of P. stenolobum according to Dr. Gonçalves.  Click here to see that plant on this website

The inset photo of a cluster of spathes (above) was provided by Dr. Tom Croat of the Missouri Botanical Garden.  Dr. Croat's specimen is quite large in comparison to our specimen.  However, in the year since our specimen was photographed it has more than doubled in size and height. 

We grow our specimen in reasonably bright light that is only sometimes shaded.  The plant is in very well draining soil mixed with peat, orchid bark and Perlite™.  My thanks to Julius Boos for his input into the research on this species

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