Gorgona_1.jpg
Photo credit O. Vargas at La Selva
Aristolochia gorgonaDutchman's Pipe [common name for species within the genus Aristolochia]
Classification:Kingdom: Plantae
Subkingdom: Tracheobionta
Superdivision: Spermatophyta
Division: Magnoliophyta
Class: Magnoliopsida
Subclass: Magnoliidae
Order: Aristolochiales
Family: Aristolochiaceae
Genus: Aristolochia
Species: A. gorgona [5]

Naming:
Aristolochia gorgona, a plant with an unpleasant appearance, tentacles covering the surface of the limb, and a foul, rotten smell, is named after the Gorgons, three monstrous sisters within Greek mythology with snake hair and poisonous breath. Aristolochia gorgona, a new species as of 2002, has been confused with Aristolochia grandiflora in the past due to their similarities.[1]

Range and Abundance:
Aristolochia gorgona is found within the Atlantic lowlands of Costa Rica as well as two sites in central and eastern Panama. It is believed that these plants may also grow in southern Nicaragua and in the northern depart
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Geographic Range
ment of Chocó in Columbia as specimens have been gathered within close proximity to the borders of these countries. Furthermore, they are generally found at elevations ranging from sea level to 100 meters. However, they grow at an elevation up to 600 meters in the Cordillera de Tilarán, a mountain range in Costa Rica. Aristolochia gorgona is not an especially common flower.[1]

Habitat:
Aristolochia gorgona plants are typically found along the edges or in the vicinity of streams, often within secondary growth vegetation. Specifically at La Selva Biological Station, these plants, as herbaceous vines, are known to climb the crowns of small and medium sized trees. However, Aristolochia gorgona do not climb the crowns of tall canopy trees. Observers at La Selva (B. Hammel and J. Trainer) have collected samples of Aristolochia gorgona climbing old cacao trees.[2] Furthermore, similar to Aristolochia grandiflora, a plant species often confused with Aristolochia gorgona, branches from the main stem of the plant may descend towards the ground and grow along the forest floor (creating a runner) which can eventually produce roots and develop into new Aristolochia gorgona, allowing for the propagation and spread of the species. Additionallly, flowers are typically positioned 3 to 15 m from the forest floor.[1]

Coloration and Morphology:
Aristolochia gorgona is a herbaceous vine (lacking woody tissue) that possesses a stem and leaves with a distinct smell.[1] The morphology of Aristolochia gorgona is quite complex:

Stem:
The ribbed, coiling stem of Aristolochia gorgona grows in diameter from 3-4 mm to 1.5 cm throughout maturity. The stem is smooth, lacking projections or hairs.[1]

Leaves:
The simple leaves (not divided along the blade) of Aristolochia gorgona are alternate (singularly attached to the stem at nodes in alternate directions) and
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Cordate Leaf, Photo credit O. Vargas at La Selva
distichous, or arranged in two vertical rows on op
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Cordate Leaf, Photo credit O. Vargas at La Selva
posing sides of the stem. Furthermore, the leaves are triangular-cordate (heart shaped) with the stalk (petiole), which varies between 2.5 and 10 cm long, attached to the cleft of the heart-shaped leaf. The length of the blade of the leaf is between 5 and 27 cm long and the leaves are generally between 5 and 21 cm in width. The upper surface of an Aristolochia gorgona leaf, or adaxial side, is smooth, while the underside of the leaf, or abaxial side, is predominately smooth, but may contain some hairs or projections. Finally, three main veins characterize the surface of the leaves and are especially distinct on the abaxial side of the leaf.[1]

Inflorescences (flowering portion of a plant):

The inflorescences of Aristolochia gorgona are composed of solitary, independent flowers, which possess a rotten odor. The pedicel of the plant or portion of the stem directly under the flower, and the ovary are 8 cm long, ribbed, and reddish in color. Furthermore, the peduncle, or area of the stem below the flower, but above the leaves, is 6 to 10 cm long. The plant also possesses small leaf-like structures, or green
Aristolochia_gorgona_2.jpg
Morphology of Aristolochia grandiflora, a species similar in structure to Aristolochia gorgona: bracteole (br), ovary (ov), gynostemium (gy), utricle (ut), syrinx (sy), tube (tu), annulus (an), appendix (ap), Photo credit source 4
bracteoles, right above the flower.[1]

Calyx:
The calyx of the Aristolochia gorgona flower is especially complex and can be divided into various subcomponents. The three-dimensional calyx is formed of united sepals (modified leaves) that provide a layer of protection for the bud.[1]

- Utricle: The pear-shaped utricle (membranous envelope enclosing fruit) is approximately 14 to 19 cm by 5.5 to 10 cm. The cream-colored external surface of the utricle sac or envelope is
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Structure of hypothetical Aristolochia Plant, Photo credit source 3
characterized by six purple ribs and a network of veins. Internally, the utricle is white with some small hair-like projections and purple spotting.[1]

- Nectary: The oval-shaped nectary is located within the interior of the utricle and serves as the site of nectar secretion. The nectary is 3.2 cm by 1.4 cm and is an orange/brown color with a purple band.[1]
- Syrinx: The syrinx projects into the utricle sac and serves as the juncture between the utricle and the tube.[3] The syrinx is cylindrical, 3.5 cm long, 1.4 to 1.7 cm in diameter and possesses a cream-colored surface with a purple rim.[1]
- Tube: The sigmoid shaped tube consists of two sections, the gullet (which is attached to the syrinx) and the vestibule. The two divisions are separated by a short 2 mm wide passage classified as the bottleneck. The tube is 12.5 cm long and, like the utricle, cream-colored with purple external ribs. The gullet is 7.5 cm long and 2.8 cm wide and the vestibule chamber is 5.0 cm long and 7.5 cm wide.[1]
- Annulus: The annulus serves as the junction between the tube and the limb.[3] The annulus is a dark orange/brown color.[1]
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Tentacles of Limb, Photo credit O. Vargas at La Selva

- Limb: The limb is cordate (shaped like a heart) and consists of two wide lobes partly folded underneath the tube. The limb is between 25 and 31 cm long and between 25 and 30 cm wide. The external coloration of the limb is cream and puple and the internal coloration is cream with orange/brown spots. The limb is a darker brown color around the opening. The limb possesses a velvety texture and long, thin projections, or tentacles, cover the surface. These orange/brown tentacles are cylindrical in shape and 5 to 20 mm long and 1 to 2 mm thick. Furthermore, a 5 cm long, 2 mm wide, twisted cauda, or
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Inside Fruit, Photo credit O. Vargass at La Selva
appendix, is attached to the apex of the limb and is directed upwards.[1]


Gynostemium:
The gynostemium is the location of the male and female organs and is situated at the top of the utricle.[4] This cream-colored structure is 13 mm high and 7 mm wide and consists of a purple colored base. The six pollen-bearing anthers are yellow, while the surface of the female reproductive structure, the stigma, is white.[1]

Fruit:
The fruit of Aristolochia gorgona consist of multi-seeded cylindrical capsules approximately 6 to 7 cm long and 3.5 cm wide, characterized by a green color with purple vertical ribs. The fruit is dehiscent, or opens naturally upon reaching maturity.[1]

Seeds:
The solid, egg-shaped seeds of Aristolochia gorgona are between 13 and 18 mm long, 11 to 17 mm wide, and 2.0 to 2.5 mm thick with brown coats.[1]

Distinguishing between Aristolochia gorgona and Aristolochia grandiflora[1]:


Aristolochia gorgona
Aristolochia grandiflora
Leaves:
wider, rounder outline, lighter green color
narrower, darker green
Cauda appendix:
short, 5 cm long
long, 20 - 50 cm (even as a bud). cauda as likely odor-producing organ
Limb:
cream surface with large pink to brown random blotches, covered with tentacles on surface (tentacles likely source of odor), fringed limb folded/bent under tube (even as a bud)
smooth limb, lacks tentacles, funnel-shaped limb, smaller dark maroon spots in checkered pattern
Calyx:
larger utricle and tube
smaller utricle and tube

Diet:
As a herbaceous vine, Aristolochia gorgona climbs up small and medium sized trees in order to gain access to greater sunlight

Behavior:

Reproduction/ Pollination:

Aristolochia trap their pollinators by effectively deceiving the pollinator through scent and appearance to enter the utricle of the calyx under the false assumption that a source of protein can be found within the plant. Observations at Los Tuxlas, Veracruz, Mexico suggest that flies within the order Diptera are the most effective pollinators of Aristolochia grandiflora, a species with great similarly to Aristolochia gorgona. During the first day of anthesis, the female, or pistillate, phase of the plant and the state at which the flower is in full bloom, the plant possesses a strong carrion odor, and a lighter colored utricle which entices the pollinators to enter the gynostemium. Furthermore, the constricting syrinx and annulus, which are covered with trichoms (narrow floral tubes), assist in ensuring the entrance of pollinators into the deep gynostemium. During the second day of anthesis, the male, or staminate, phase, anthers deposit pollen on the pollinators. The flower subsequently opens to allow for the escape of pollinators. Changes in odor, coloration, and structure allow for the release of the pollinators. The flies or other pollinators are then capable of carrying the pollen to a flower in the female phase. On the third day, the flower decays and the calyx is either auto-digested or falls off.[4] It is likely that Aristolochia gorgona undergoes pollination in the same manner due to the structural similarity with Aristolochia grandiflora and the yearly flowering of the species. Flowering of Aristolochia gorgona occurs throughout the year, and the same is believed to be true about the fruits of this plant, however, samples have been collected predominantly in March, April, and July.[1]

Ecology:
Seed Dispersal:
It is believed that the seeds of Aristolochia gorgona are dispersed via water dispersal as these thick seeds lack wings and are often found along the edges of streams.[1]

Interactions with Other Species:

Within the utricle of Aristolochia gorgona plants, researchers have noted the presence of flies in the Muscidae and Phoridae families. Finally, beetles within
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Interior of utricle, Photo credit O. Vargas at La Selva
the family Staphylinidae have been found in the utricles of these plants.[1] Studies with Aristolochia grandiflora indicate that it is unlikely that there exists a mutualism between the flies and the plant, as the flies are probably unable to grow on the rotting flowers, they are unlikely to ingest the pollen of the plant, and the species are unlikely to provide nectar for the flies. Furthermore, observations suggest that a reduced amount of fly larvae was present within plants inhabited by the beetles. Therefore, the beetles may feed on the fly eggs and
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Interior of utricle, Photo credit O. Vargas at La Selva
larvae within the interior of the flower.[4] Researchers have suggested a possible hybridization between Aristolochia grandiflora and Aristolochia gorgona because the same species of flies and beetles have been found in the utricles of both plants. However, Aristolochia gorgona is typically found in a different area of Costa Rica, along the Pacific coast.[1]



Experiences During Our Trip to Costa Rica:
Although we did not observe my plant during our 2010 trip to Costa Rica, Aristolochia gorgona plants have been seen at La Selva along flat areas of good sediment and often nearby streams or swamps (including the STR trail, the Arboleda, and the Sura trail).


References:
1. Blanco, Mario A. "Aristolochia gorgona (Aristolochiaceae), a New Species with Giant Flowers from Costa Rica and Panama." The New York Botanical Garden 54.1 (2002) : 30 - 39.
2. "Aristolochia gorgona." La Flora Digital de la Selva. [Online] Available <http://sura.ots.ac.cr/local/florula3/en/fr_colls.php>.
3. Pfeifer, Howard W. "Revision of the North and Central American Hexandrous Species of Aristolchia (Aristolochiaceae)." Annals of the Missouri Botanical Garden 53, 2 (1966) : 115 - 196.
4. Burgess, K.S., J. Singfield, V. Melendez, P.G. Kevan. "Pollination Biology of Aristolochia grandiflora (Aristolochiaceae) in Veracruz, Mexico." Annals of the Missouri Botanical Garden 91, 2 (2004) : 346 - 356.
5. "Classificati​on" [Online] Available <http://plants.usda.gov/java/ClassificationServlet?source=profile&symbol=ARGR2&display=31>.