Anthurium jenmanii Engl.

Many sellers sell Anthurium bonplandii subsp. guayanum and call it Anthurium jenmanii
The two species are very different species.

NOTE:  This text contains photos of both Anthurium jenmanii and Anthurium bonplandii subsp. guayanum.  Please read the captions beneath each photo.

 

A member of Anthurium section Pachyneurium which contains the "birds nest" forms, Anthurium jenmanii was first scientifically  collected on the Caribbean island of Trinidad.  Even though collectors often believe Anthurium jenmanii is rare in nature it is commonly found on the windward islands of the southeastern Caribbean including Tobago, St. Lucia, Martinique, Dominica, St. Vincent, Montserrat, Antigua and Grenada.   The species grows either terrestrially, as an epiphyte (eip-FIT) on the branches of a tree or as a lithophyte (litho-FIT) on stone.

 

Anthurium jenmanii is also found in South America's Guiana Shield  which includes French Guiana, Suriname, Guyana, Venezuela and the extreme northern portion of the Amazon basin in Brazil's Amazonas State.  Anthurium jenmanii is almost always collected at elevations below 500 meters (1650 feet) in moist forest regions but also in open dry woodlands.   My friend Dutch naturalist Joep Moonen (pronounced yupe) who lives and works in French Guiana has indicated in multiple personal communications the species is often observed very near sea level.  Joep can be seen in the photo at the top of this page with an adult specimen of Anthurium jenmanii. 

The leaf blades of Anthurium jenmanii are coriaceous (leathery to the touch) and broadly oblanceolate to elliptic but are rarely ovate-elliptic.   Any leaf blade that is oblanceolate is spear shaped but widest above the center of the blade and broadest near the middle or in the upper one fourth.  The leaf blades near the base are obtuse (blunt) and rounded or may be slightly oval.  The edges (margins) of the blades are moderately undulated (wavy).  The upper blade surface (adaxial side) is semi-glossy to glossy and is a yellowish green.  The lower leaf surface (abaxial side) is matte to only slightly glossy and is a bit paler in color.   In regard to the color of the blades shown at right, below, Joep wrote, "Please notice the yellow leaves. This is normal in the dry season when they are exposed to a lot of light  such as on inselbergs.  I know one inselberg where there are hundreds if not a thousand A. jenmanii specimens but deep in the forest the species is a lot less common."

There should be 5 to 13 primary lateral veins on each side of any leaf of Anthurium jenmanii.   The veins near the top of the blade merge into the  collective vein  The collective vein is a specialized vein which runs around the circumference of an Anthurium's blade and is a primary characteristic used to determine if a specimen is, or is not, an Anthurium species (see photo below).  The lateral leaf veins are raised near the midrib (center of the leaf) but are slightly sunken at the edges (margins).   The minor veins, known as the tertiary veins, are sunken on the upper surface but are raised on the leaf's underside. 

The lower surface (abaxial) of the leaf blade is substantially less glossy than the upper (adaxial) blade surface.  The leaves of Anthurium jenmanii are often both large and coriaceous to moderately coriaceous.  The term "coriaceous" simply means leathery to the touch.   The upper blade's surface is semi-glossy as well as moderately bicolorous (dual colored).  The midrib is convex (pushes upwards) on both the upper and lower surfaces while the tertiary (lesser) veins are sunken on the upper surface but raised on the lower surface.  

Anthurium jenmanii is known to be variable having multiple leaf forms throughout its native range.  This link offers a more complete explanation of natural variation within aroid and other plant species.  Click here. 

The petioles of Anthurium jenmanii support the blades are described in the journals of aroid botanist Dr. Thomas B. Croat Ph.D., P.A. Schulze Curator of Botany at the Missouri Botanical Garden in St. Louis as being sharply to slightly "D" shaped but are flattened to slightly convex on the upper surface while rounded on the underside.  The surface of Anthurium jenmanii's petiole is slightly speckled.  The "D" shape is a reference to the appearance of the petiole when cut and viewed as a cross section (cut in half).   However, due to natural variation in the species Anthurium jenmanii may also be sulcate which indicates a depression (C shaped) in the stem (see photo right taken in the greenhouse of the Missouri Botanical Garden collection).  The petiole is scientifically a stalk to which the lamina of the leaf blade is attached.  The petiole is often referred to by collectors as the "stem" but correctly the stem is at the base of the plant.  

At the top of any Anthurium species' petiole you will find the geniculum (see photo right, above) which is slightly larger than the petiole in size.  The geniculum allows the leaf blade to rotate much like an elbow or a knee in order to orient itself to find a brighter source of light.  The geniculum of Anthurium jenmanii is slightly paler and only moderately thicker than petiole.  Anthurium jenmanii has short internodes on the stem.  An internode is a segment of stem between two nodes and the node is where a leaf may emerge. 

Once a new leaf is produced, it is surrounded by a sheath-like structure known to a botanist as the cataphyll.  The cataphylls of Anthurium jenmanii are lanceolate (lance shaped) and sometimes purple.   A cataphyll is a bract- like modified leaves that surround any new leaf and whose purpose is to protect the emerging leaves as they develop.  On a specimen of Anthurium jenmanii the cataphylls remain after drying as a fibrous material similar to coconut husk. 

During the year 2007 aroid collectors from Indonesia were paying phenomenal prices for a single specimen of various plants being sold as "Anthurium jenmanii".  More than a few specimens were hybrids of other plant species, not the actual species known to science as Anthurium jenmanii.  One principal reason collectors in Indonesia were seeking what they thought to be  "Anthurium jenmanii" was they believed the species produced a juvenile bright burgundy to red leaf.  Anthurium jenmanii does not produce a red leaf according to botanical experts including aroid botanist Dr. Croat.  My friend Joep made this comment in a personal email, "I have never seen a red jenmanii but that does not say much since they have a big distribution and there might be mutations as well".   As a result it is likely that 95% of the photos labeled "Anthurium jenmanii" on Google images are not Anthurium jenmanii but instead are a hybrid of Anthurium bonplandii subspecies guayanum.  All the photos labeles as Anthurium jenmanii on this page were taken either in the wild or are from the vouchered botanical collections of either the Missouri Botanical Garden in St. Louis, MO or the Jardin Botanique de la Villa in France.

Despite common misconceptions, species within the Neotropical genus Anthurium are not found naturally in Asia or the Pacific region but that does not mean they are not grown all over the world!  People obviously grow Anthurium species in many countries, but Anthurium are not naturally found in the Pacific basin or Asia and are strictly found naturally within Mexico, Central America, South America, and the West Indies. 

My thanks to Dr. Croat for his input and the use of his published material.  Thanks also to botanist David Scherberich, Jardin Botanique de la Ville de Lyon, Parc de la Tete d'Or, France for the use of his photographs of Anthurium jenmanii as to to Phil Nelson and Harry Luther at the Marie Selby Botanical Gardens in Sarasota, FL.  Also my sincere thanks to Emily Colletti who is the chief aroid greenhouse keeper at the Missouri Botanical Garden in St. Louis, MO for her assistance in photographing a specimen of Anthuiurm jenmanii in the garden's collection and finally to my friends Joep Moonen, Bill Rotolante and aroid expert Leland Miyano for their assistance.

Joep Moonen along with his wife Marijke and son Bernie live and work at their Emerald Jungle Village in the rain forests of French Guiana.  A Dutch naturalist who regularly takes botanists and scientists into the rain forests of the Guiana Shield to search for new and undiscovered animal and plant specimens, Joep has been honored by having several species including Anthurium moonenii, Philodendron moonenii and others named to science in his honor.   If you enjoy spending time in a rain forest filled with exotic creatures and extremely rare exotic plant species Joep Moonen will enjoy introducing you to the rain forests of northeast South America.  

The Emerald Jungle Village website can be found at  http://home.planet.nl/~gumamaus/

For eco-tour information contact Joep Moonen at EmeraldJungleVillage@wanadoo.fr

Additional photographs by botanist David Scherberich can be seen here:  http://www.aroidpictures.fr/GENRES/anthuriuma-l.html