Anthurium plowmanii Croat

 

A large epiphytic or epilithic species, Anthurium plowmanii is placed in Anthurium section Pachyneurium, but is unusual in that section.  The unusual features include a spadix, which is commonly longer than the peduncle.  The peduncle is the plant organ that supports the inflorescence and the spadix is a portion of the inflorescence. This feature is shared only with Anthurium solomonii.  An additional distinctive feature is the either "C" or "U" shaped petioles. The petiole is the portion of the leaf that supports each leaf.  For those unfamiliar with botanical terms, an epiphyte is a plant that normally grows attached to another plant, in this case on the branches of a tree.  An epilithic species is one capable of growing attached to stone.

The leaf blades of Anthurium plowmanii can grow as long as 2 meters (6.5 feet) and as noted above the petioles will have the shape of either a "U" or a "C" when cut as a cross section.  The leaves stand erect but may also spread laterally in a rosette fashion.  The petioles are typically 10 to 40cm long (roughly 4 to 15.75 inches) but may grow as long as 50cm (19.7 inches).  The geniculum (a bump in the petiole just beneath the leaf blade) is thicker than the petiole and becomes fissured with age. Aroid expert Julius Boos explains further regarding the purpose of the geniculum, " the geniculum acts like a ''wrist'', and actually allows the leaf blade to turn or rotate to align itself with the light source and occurs only on some aroid genera including Anthurium and Spathiphyllum but not on others."  The leaf blade is coriaceous (leathery) and typically measures from 20 to 56cm (7.9 to approximately 22 inches) wide.  The  blades are always broadest near the center.

The blades of Anthurium plowmanii are distinctive in that they possess an undulated appearance (wavy) near the blades' edges.  The upper surface of the leaf should be matte to semi-glossy in appearance but have been reported to be slightly glossy.  Although a variable species with a variety of forms, the blade should be dark green in color with the underside appearing matte to only slightly glossy.   Anthurium species are known to be highly variable and not every leaf of every specimen will always appear the same. 

Anthurium plowmanii has many known forms.  This link explains in greater detail the scientific principals of natural variation and morphogenesis.  This link offers a more complete explanation of natural variation within aroid species. 
Click here. 

The inflorescence of Anthurium plowmanii stands erect but may also be slightly spreading in appearance.  The inflorescence of any Anthurium species is the reproductive organ of the plant and is composed of a spathe and spadix.  Often called a "flower", the inflorescence is not considered a flower by those who are botanically trained.  The flowers grow along the surface of the spadix which is found at the center of the inflorescence and are quite small requiring magnification to view.  The spathe is simply a modified leaf.  The peduncle which supports the inflorescence typically measures 6 to 32cm (2.35 to 12.6 inches) but may be shorter on plants just reaching maturity.  The spathe is often reflexed (turned backwards) but may also be rolled.  The coloration of the spathe is violet purple or green tinged with purple and the shape is similar to a spear, known to a botanist as lanceolate.  Typically the spathe will measure from 5 to 26cm (2 to 10.25 inches) but can grow to as long as 29cm (11.4 inches) in length.   Once pollinated the berries produced on the spadix are red and are oblong to obovoid while slightly rounded at apex in shape.    Each berry will produce 1 to 2 seeds. 

Being commonly considered a "birds nest" form, Anthurium plowmanii is easy to culture.   The species grows well in collections provided it is protected from temperatures that never drop below freezing and preferably not below 12.75 C 55 degrees F).  In cold climates the species must be grown in a greenhouse.  Anthurium plowmanii is a variable species and may produce leaf blades with widely varying forms.  Dr. Croat has identified certain forms of the plant as a ruffled margined form of Anthurium plowmanii.  It is important to remember Anthurium plowmanii is a "variable" species capable of producing more than one leaf form.  Variableness is not uncommon within aroid species. 

There is also a form commonly sold as Anthurium plowmanii 'Fruffles'.  In a note to aroid expert Julius Boos, Dr. Tom Croat of the Missouri Botanical Garden in St. Louis had these comments about that particular variation, "I used to have it but am not sure what I have now.  That form, so far as I know, was collected by Fred Fuchs in Bolivia.  I remember that Tom Fennell was interested in culturing it and I believe that I gave them material to carry this out but I don't know if they did or not." 

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