Last revision 21-Jul-2020
Skip Navigation LinksMain Page  »  Phragmipedium  »  Species  »  exstaminodium
Phragmipedium exstaminodium Castaño, Hágsater & Aguirre
in Orquídea (México City), 9(2): 191-197 [193] (1984).
Synonyms :
Paphiopedilum exstaminodium (Castaño, Hágsater & Aguirre) V.A. Albert & Börge Pettersson in Lindleyana, 9(2): 137 (1994).
Phragmipedium humboldtii subsp. exstaminodium (Castaño, Hágsater & Aguirre) J.T. Atwood & Dressler in Selbyana, 19(2): 245-248 [247] (1998), nomen illegitimum.
Phragmipedium warszewiczii subsp. exstaminodium (Castaño, Hágsater & Aguirre) Christenson in Journal für den Orchideenfreund, 13(2): 143 (2006).
Phragmipedium humboldtii subsp. exstaminodium (Castaño, Hágsater & Aguirre) J.T. Atwood & Dressler ex J.M.H. Shaw in The Orchid Review, 119 (Supplement): 84 (2011), nomen illegitimum.

Phragmipedium triandrum Archila in Revista Guatemalensis, 2(3): 3-7 [6] (1999). - A dubious entity by some considered synonymous with Phrag. exstaminodium.
Type(s) :
Etymology : The specific epithet exstaminodium points unmistakably to the missing staminode, which is present in all other members of this genus.
Plant : The epiphytic plants are up to 50 cm high. The simple roots come from a short rhizome.
Leaves : From the short stem comes a fan of leaves. The almost linear leaves are up to 45 cm long and 4 cm wide. The lower leaves are the longest and going upwards the leaves become gradually shorter.
Inflorescence : The inflorescence comes as with all species from the genus Phragmipedium from the centre of the fan of leaves, is elliptic and is covered with short downy hairs. At the bases the diameter of the inflorescence is about 6 mm. The length can be up to 50 cm. Normally it carries 2 large flowers which open simultaneously.
Flower : This species is easily distinguished from the other members of the subgenus Phragmipedium because of the missing staminode.
Habitat : This species has only been found growing epiphytic on trees and lianas 1,5 m and higher from the ground. It grows in forests with coniferous and oak trees, as well as in deciduous forests at altitudes of 1400 to 1700 m. Phrag. exstaminodium has never been found growing below 1400 m, which might suggest that it is very unlikely that it exists in the evergreen tropical rainforests. The species inhabits an area that has a fairly regular and generous rainfall. The relative humidity of the air is about 60-90%. This becomes less in the period between May and December when the rainfall reduces. These conditions make that layers of mosses and lichens are growing over the roots of the plants. The species shares it's habitat with other orchids like Cymbiglossum (Odontoglossum) bictoniense, Lycaste skinneri and Trichopilia tortilis.
The above mentioned conditions continue into Guatemala, therefore it might be possible that this Phragmipedium-species can also be found in this country.
Distribution : This species is only known from Mexico, with growing sites in the state of Chiapas near Tziscao at the border with Guatemala. It's very likely that this taxon is also present in North-Guatemala.
Flowering Season : In Mexico it flowers from May until July.
Chromosomes : 2n = 28 (Karasawa).
History : This slipper orchid from Chiapas, Mexico is already known for a long time. Plants of this taxon were collected several time; R.L. Dressler in 1953 and 1954, E. Hágsater in 1963, G. Castaño in 1968, E. Hágsater in 1971, Pontes in 1975 and others. So far it was the general opinion that these plants belonged to Phrag. caudatum (Lindley) Rolfe. In the second half of the 1970's several people started to doubt the classification of these plants from Chiapas. Because it became clear that these plants differ in various details from Phrag. caudatum, especially the structure of the column. Round the same time Leslie Garay (1979) published his revision of the genus Phragmipedium in which he concluded that the caudatum from Guatemala is in fact Phrag. warscewiczianum, which is now known as Phrag. popowii. Garay's classification of the "caudatum-group" was heavily based on the shape of the staminodes. In the population of Chiapas the staminode was missing all together. And it was clear that this was a stable characteristic. Next to that the Chiapas plants differ from Phrag. warscewiczianum (popowii) from Guatemala. So it was believed that the plants from Chiapas, Mexico are a separate species instead of a peloric caudatum warscewiczianum (popowii).
The species was described may 1984 by Guillermo Castaño Ramirez, Eric Hágsater and Ernesto Aguirre Leon as Phrag. exstaminodium.
Comments : Phrag. exstaminodium is a very rare and endangered species. It is only known from two national parks in Mexico. Both populations consist of a very limited number of plants. Eric Hágsater was in 1989 project manager of the Project Phragmipedium exstaminodium for the WWF. For this project 3 trips were made to the natural habitat to research this taxon. During these trips only 28 plants in total were found. This number indicates very clearly how endangered this species is. The fact that this species is now near extinction is almost certainly caused by overcollecting shortly after its discovery.
The local name for this plant is "Tanal de Bigotes". Tanal is a name given to all epiphytic plants by the Tzotzil-Tzetzal Indians. Bigotes means something like moustache.
The striking characteristic for this taxon is the missing staminode, which is a completely stable feature of the plants in Chiapas. It appears to be the result of natural selection with an important influence on the pollination mechanism.

At first it was thought that small bee species pollinated this species, as was observed with Phrag. caudatum by Fowlie (1972), but later field studies produced evidence that Phrag. exstaminodium is autogamous (self-pollinating).