Anthurium bonplandii, Anthurium bonplandii subsp. guayanum, Anthurium bonplandii (G.S. Bunting) Croat,Exotic Rainforest rare tropical plants

Anthurium bonplandii subsp. guayanum, Photo Copyright 2007, Joep Moonen, French Guiana A member of Anthurium section Pachyneurium which contains all the birds nest forms, Anthurium bonplandii was described to science by George Bunting in 1975 from a specimen observed in the Amazon region of Venezuela near Río Orinoco. Anthurium bonplandii subsp. guayanum is a unique subspecies of Anthurium bonplandii that has been further described by Dr. Tom Croat. Anthurium bonplandii has been divided into several subspecies although all are considered to be Anthurium bonplandii. However, Anthurium bonplandii subsp. guayanum is distinctive. According to personal communication with Dr. Croat Anthurium bonplandii subsp. guayanum is likely to be the plant often incorrectly sold on internet auctions as Anthurium jenmanii.

Anthurium bonplandii subsp. guayanum is found in Bolivar state in the Guiana highlands of Venezuela but is also found in Guiana, northern Brazil and Suriname. Since Anthurium bonplandii is variable the various subspecies including Anthurium bonplandii subsp. bonplandii, Anthurium bonplandii subsp. cuatrecasii, Anthurium bonplandii subsp. guayanum and Anthurium bonplandii subsp. rionegrense may be easily confused in regions where their ranges overlap.

Anthurium jenmanii, Photographed at the Missouri Botanical Garden, St. Louis, MO., Photo Copyright 2009 Steve Lucas, www.ExoticRainforest.com In the year 2007 Anthurium bonplandii subsp. guayanum may have become one of the most confusing Anthurium species in the world. According to email exchanges as well as personal conversations in his office, aroid botanist Dr. Thomas B. Croat Ph.D., P.A. Schulze Curator of Botany of the Missouri Botanical Garden in St. Louis explained the plant sold most often in Indonesia and on eBay as Anthurium jenmanii, is not likely that species.

When asked by an Indonesian collector for an opinion of whether or not a specimen in that collector's possession was Anthurium jenmanii or Anthurium bonplandii subsp. guayanum, Dr. Croat wrote: "Your plant is what I treated as Anthurium bonplandii Bunting var. guayanum (Bunting) Croat. Some still call this Anthurium guayanum but I chose to consider it a variety of A. bonplandii owing to the immense variation in both species. Anthurium jenmanii Engl. is very different, having a spathe that soon falls off and also by lacking the dark punctuation on the lower blade surface." (Please see photo left)

$Anthurium bonplandii subsp. guayanum glandular punctates, Photo Copyright 2008, Steve Lucas, www.ExoticRainforest.com$ Anthurium bonplandii subsp. guayanum occurs in the Guiana Shield in the highlands of Venezuela, Brazil, Guyana, and Suriname with the majority of specimens seen in Venezuela's Bolivar State. Found at elevations ranging from as low as near sea level to 100 meters (300 feet), the average elevation is 400 to 1,500 meters 1,300 to 4,900 feet) on sandstone outcroppings and growing on sandstone boulders. Anthurium bonplandii subsp. guayanum can sometimes be observed growing in white sand in both the open sun and in partial shade. A variable Anthurium subspecies, Anthurium bonplandii subsp. guayanum occurs in pre-mountainous moist and wet rain forests as well as tropical wet forest zones.

A. bonplandii subsp. guayanum is primarily terrestrial and is found less frequently as an epiphyte (ep-a-FIT) growing on trees. Within the rain forest it is not uncommon to see very large Anthurium specimens residing high on a tree branch. The species was reported by Bunting to be a favorite place for ants to build a colony at its base. Plants which attract ants are known as myrmecophytes.

The message below was sent to Denis Rotolante who with his son Bill are owners of Silver Krome Gardens in Homestead, FL. Dr. Croat wrote, "There has not been anything published since I published my revision of Anthurium sect. Pachyneurium in the Annals of the Missouri Botanical Garden 78(3): 539-855.1991. The attractive, coriaceous bird's nest sometimes called "jenmanii" sometimes A. bonplandii guayanum, sometimes as A. guayanum had the young leave reddish on the lower surface when young. I treated this as Anthurium bonplandii ssp. guayanum but it might just as easily be considered a distinct species as was treated by George Bunting. It is just that there is so much variation in all of those taxa that I could not find clear separation in them. Certainly this plant did not have anything really in common with A. jenmanii, a species which has a spathe that soon withers and falls off. " Within his message Dr, Croat was referring to his journal, Annals of the Missouri Botanical Garden 1991, A Division of Anthurium Section Pachyneurium, Volume 78, #3. According to Tom and the information specified in that journal regarding both Anthurium jenmanii and Anthurium bonplandii subsp. guayanum the species that produces the purple/red leaf is not Anthurium jenmanii but Instead is Anthurium bonplandii subsp. guayanum.

Anthurium bonplandii subsp. guayanum can be recognized by usually large and frequently broad leaf blades as well as by possessing thick leathery (coriaceous) leaves. The species has conspicuous dark glandular punctations (dots) on the abaxial (lower) leaf surface. As opposed to Anthurium bonplandii subsp. bonplandii, Anthurium bonplandii subsp. guayanum possesses oblanceolate to obovate (both oblong and lance shaped but wider near the tip or oblong and widest at the center) leaf blades while Anthurium bonplandii subsp. bonplandii produces largely an elliptic leaf Anthurium bonplandii subsp. guayanum sulcate petiole, Photo Copyright 2008, Steve Lucas, www.ExoticRainforest.com shape.

The blades Anthurium bonplandii subsp. guayanum are oblanceolate to obovate in shape, The adaxial (upper) surface of the leaf blades are dark and semi-glossy. One notable feature to Anthurium bonplandii subsp. guayanum is the midrib is broadly sulcate at the base. Sulcate indicates either a canal known as a sulcus or having numerous fine parallel grooves which may require a magnifying glass to be clearly observed. The primary leaf veins are raised while the tertiary (minor) veins are sunken. The underside of the leaf blade is slightly paler in color and is semi-glossy to matte in its sheen. On the underside of the leaf the tertiary veins are raised. As an adult, the leaf blades of Anthurium bonplandii subsp. guayanum are arching and stand erect

The blades are supported by the petioles which collectors frequently refer to as "the stems". In science the stem is at the base of the plant and the leaves grow from the nodes along that stem (see photo below, left). The petioles are the stalk that supports a leaf and attaches the blade to the stem. The petioles of Anthurium bonplandii subsp. guayanum are "C" shaped but may also be sharply "D" shaped when cut and viewed as a cross section. The petioles are also sulcate. Again, the term "sulcate" means scored or grooved in a parallel fashion (see photo right). The internodes of Anthurium bonplandii subsp. guayanum are short. An internode is a segment of the stem between two nodes on that stem and the node is where a leaf may emerge.

Anthurium bonplandii subsp. guayanum collective vein, Photo Copyright Buddy Poulsen Once a new leaf is produced, it is surrounded by a sheath-like structure known to as the cataphyll. The cataphylls are bract like modified leaves that surround any new leaf and whose purpose is to protect the emerging leaves as they develop. The cataphylls of Anthurium bonplandii subsp. guayanum are sub-coriaceous (less than leathery to the touch) and are lanceolate as well as tinged reddish.

All Anthurium possess a collective vein which runs near the edge of the leaf blade. The collective vein is a specialized vein and often runs around the entire circumference of an Anthurium's blade (not always) and is a primary characteristic used to determine if a specimen is, or is not, an Anthurium.

An aroid, all Anthurium species reproduce via the production an inflorescence. The stalk that supports the entire inflorescence is the peduncle. When an Anthurium is "in flower" the reference is to the tiny flowers containing both male and female sexual parts that grow on the spadix at the center of the inflorescence. Unlike Philodendron species which contain imperfect flowers having only a single sex Anthurium possess perfect flowers containing both sexes. To help prevent self pollination nature has designed the female flowers to be receptive before the male portion of a flower produces pollen so in most cases an insect must bring pollen from another plant.

The spathe and spadix make up the reproductive portions of the plant and the spathe is sometimes incorrectly called a "flower". Rather than a flower the spathe is a modified leaf. The spathe of Anthurium bonplandii guayanum is green and is reflexed (turned back) while the spadix at its center hangs pendently (downward) and vaguely resembles an elongated pine cone. The spadix is a spike on a thickened fleshy axis which can produce tiny flowers. The spadix may be reddish to purple to purple/brown at anthesis and is ready to be pollinated.

Once the female flowers on the spadix have been fertilized by a Cyclocephala beetle they produce berries which are reddish purple as well as obovoid (oval and oblong). When "in fruit", those berries contain the seeds of the aroid and the entire structure is known as an infructesence. Joep Moonen made this observation regarding berry coloration and seed shape. "The berries and seeds from both species have the same color: purple-red, fading to whitish at the base. However the shape is different. A. jenmannii: oval like an egg, A. bonplandii: shorter seeds, they look triangular to trapezium from the side." You can see a photograph of the seeds of Anthurium jenmanii here: Anthurium jenmanii

The beetle genus Cyclocephala is thought to contain close to 900 species of which approximately one half have been identified to science. Each Cyclocephala species appears to have been "assigned" by nature to pollinate only a few species of aroids. A link can be found at the end of this article which explains more about the pollination of aroids.