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| Tribe: | Cymbidieae |
| Subtribe: | Oncidiniiae |
| Etymology: | From
Greek = Onkos. Olof Swartz, in 1800, gave this name due to the small callus situated at the base of the lip which seams to be a wart, tumor, swelling, which in Greek is Onkos |
Carlos Eduardo
de Britto Pereira has been studying the genus Oncidium for 15 years
and based on those researches, he concluded many interesting things about
synonyms and doubtful occurrences in our country. He considers that a study of the species should be done based in three procedures: first, analyze the original material of description and all synonyms, second, analyze all material classified in herbarium, specially the material-type and, finally, examine many alive material, comes from different habitats. This is the way he took to study the genus Oncidium in Brazil: exhaustive analyze of populations included those in their habitats, visits to herbariums to analyze the classified material, mainly the type and descriptions. Thus, he could understand some controversial points about this genus. His opinion is a resultant of a serious study which aim is a major knowledge and in proportion that this knowledge progresses, the opinions and the focus about the same point of view can change as this evolution provokes a more extensive understanding and a revision about what has already been studied. In his opinion, he should study much more to do his book. Read those considerations and understand why he can affirm certain things and goes on in doubt about some others, although he says that it is his interpretation which is not necessary infallible. Do not miss the interview presented in the virtual magazine Orchid News nº 10. |
| O. orthostates Ridl. |
Concerning
the presence of O. orthostates in the State of Goiás,
Carlos Eduardo had not the occasion to study the species which occurs there
but he considers that occurrence unlikely. O. orthostates comes from Venezuela and occurs in Brazil in frontier regions specially
with this country, in the state of Roraima. The plant of this species that
someone gave to him, has been collected in Serra do Araca which is located
in the north of Amazonas, in the frontier with that country, in São
Gabriel da Cachoeira, Negro River. |
| O. divaricatum Lindl., O. pulvinatum Lindl. O. robustissimum Rchb. f., O. sphegiferum Lindl. |
|
Vegetative
appearances The species of the Pulvinata section are characterized by a pulvinus (or pulvillus) in the callus of the lip and the differentiation of the species is done based on its shape. That is the reason of the section's name. Carlos Eduardo also based his studies about this section on this characteristic however it can be also based on the lateral lobe, if it is unbroken, serrate or fringed. Pulvillus is a cushion-shape protuberance as it was a wart, soft hairs or small points. In O. divaricatum, instead of being continuous, it has a re-entrance in each side, as it makes an ear and other ear, which can be more or less accentuated. This is the divarication. |
|
 In O.pulvinatum, the pulvinus is round, |
 in O. sphegiferum, it is long |
The
species of this section has other characteristics such as three-lobed lip
and lateral lobe is, normally, rounded. Concerning the vegetative appearance, he informs us that a plant of O. robustissimum is completely different from O. pulvinatum, (foto do CE) from O. sphegiferum and from O. divaricatum. O. robustissimum has coriaceous (leathery, tough) leaves but fleshy, we have the impression that if we press it, the finger sinks. O. divaricatum has it owns characteristics, the leaves are more rounded and the texture is more coriaceous. O. sphegiferum is more complicated. This one which occurs in Santa Catarina is like a big O. harrisonianum with tough leave. In the state of Rio, there is an occurrence of an O. sphegiferum which seems to be a small O. robustissimum with soft leave. Brief, there is plant that could be an O. pulvinatum or O. sphegiferum but would not be confused with O. robustissimum because of the kind of fleshy bluish leaf, which is different. |
|
| Vegetative Appearance | ||
The
vegetative appearance is very important to know to which section the plant
is assigned. Just looking to the plant, Carlos Eduardo can tell if the section
is Crispa, Pulvinata, Concoloria or Paucituberculata. However, if the sections
Verrucituberculata, Oblongata and part of Synsepala are involved, we can
not differentiate only by the plant. He has already seen O. concolor with so big bulbs that he never imagined that it could be this species, it seemed to be O. crispum. |
 |
On the other hand, O. crispum can be an enormous or a small plant depending on the place it grows, if under the sun, in a cool place, more humid or dried. There are plants of O. crispum which are green, brownish, entirely brown, as found in Barbacena, State of Minas Gerais. |
 |
By
the appearance of the plant, you can have an idea of the section but it
is hard to differentiate the species without seeing the flower but there
are some exceptions. |
| Terrestrials | ||
The
terrestrial species, O. batemanianum, O. sellowii, O. isopterum,
O. montanum, O. pirarense, are really hard to be differentiated
when they are not blooming. |
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 |
 |
|
O.
montanum |
O.
pirarense |
|
On
the other hand, O. warmingii is easier as it is different. It has
a long rhizome and the pseudobulb is quite round with a space between them,
you have a pseudobulb, a leaf, another space and then another pseudobulb.
The species described from Espírito Santo, Oncidium majevskyi,
has also a long rhizome and the pseudobulb is similar to O. warmingii but you can saw that they are different plants. O. flexuosum also has a long rhizome but the pseudobulb is flatted and it is epiphyte.  |
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| O. spilopterum Lindl. | |
 |
O.
spilopterum has a characteristic shape and, use the terminology of the
orchidist, the kind of skirt-like lobe and the balance of the flower are
different. It has a very complex callus and in 95% of the flowers, it is
violet-brown, violet. The intensity of the color is variable. Sometimes,
you find one with white callus however even with this variation, you can
see that it is a O. spilopterum due to shape of the lip and the complexity
of the callosity. The shape of the flower is different and the lip is too
big for its size, making him fringed, very characteristic. In Goiás,
there is a population of a species considered as O. spilopterum but he did not studied it yet so he can not give an opinion about it. |
| O. ghillanyi Pabst and O. spilopterum Lindl. | |
As
far he studied, he could concluded that they are different species: O.
ghillanyi in the section Synsepala and O. spilopterum ) in section Oblongata. |
|
According
to the taxonomy of the genus, the separation between the two sections is
exactly the difference in the lateral sepals. In the section oblongata,
the lateral sepals are free and in the section Synsepala, the lateral
sepals are concrescent, this is enough to justify the separation of the
two species. He considers that a more deep study should be done about the
two species and would like to examine more plants of O. ghillanyi,
to see if all of them are really synsepalous, those he has seen, from different
habitats were synsepalous. Besides, O. spilopterum comes from Serra
do Cipó and O. ghillanyi comes from Serra do Itambé.
Both habitats, very far from each other, had been visited by him. This subject
remains to be more studied. |
O. spilopterum |
| O. batemanianum Parm ex Knowl. & Weste. |
Has a very well characteristic callus, it is easier to recognized |
| O. caldense Rchb. F., O. ramosum Lindl., O. donianum Batem. ex Baxt. |
| Garay e Stacy consideraram O. caldense e O. ramosum como sendo a mesma espécie mas concordando com Pabst, Carlos Eduardo considera como duas espécies diferentes. O. caldense pertence à seção Oblongata, mesmo grupo do O. spilopterum. O. ramosum e O. donianum são da seção Verrucituberculata. |
| O. montanum Barb. Rodr. and O. pirarense Rchb. F. | ||
|
Garay
& Stacy in Synopsis of the genus Oncidium and Pabst &Dungs
considered them as the same species but Carlos Eduardo considered them completely
different mainly concerning the callus. O. pirarense has the name
because it has been found in Pirara, Venezuela and has been also found in
the region of Diamantina by Carlos Eduardo. Based on the drawing of the
type, he concluded that this is a valid species, different from O. montanum. |
|
O.
pirarense |
O.
montanum |
|
| O. haematochrysum Rchb. f. O. haematoxanthum Rchb. f. |
O. haematochrysum is a synonym of O. flexuosum. O. haematoxanthum is, in fact, O. flexuosum var. haematoxanthum and has
the pulvillus lemon-yellow. |
| O. edwallii Cogn. O. hians Lindl. |
|
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Species
completely different, even the color, O. hians has a lip strongly colored, half red, half yellow. O. edwallii is greenish yellow, small flower without charm which shape is different. |
