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Catasetum callosum


Common Name: The Callused Catasetum

Flower Size: 2" [5 cm]

A medium sized, hot growing Colombian and Venezuelan epiphytic species occurring at elevations around 346 meters on bushes in dry open forests with fusiform pseudobulbs enveloped basally by leaf sheaths and carrying 5, linear-lanceolate, medium green, plicate leaves and blooms in the fall and winter on a basal, arching, 12" [30 cm] long, several [10 to 15] flowered, racemose inflorescence with fragrant, inverted flowers arising on a mature pseudobulb.


This species requires a dry, fertilizerless rest in the winter.







Catasetum callosum is found in Brazil's Amazonas State (along the border with Colombia and Peru), through Venezuela and the Guianas. It grows in gallery forest along the tributaries on the left bank of the Amazon River at elevations of about 346 meters. It is also found on more open plains in the other northern South American countries.




Catasetum callosum grown by Barbara Tague of DVOS


  • The Callous Catasetum
  • Catasetum acallosum
  • Catasetum arachnoides
  • Catasetum callosum var. carunculatum
  • Catasetum callosum var crenatum
  • Catasetum callosum var crenulatum
  • Catasetum callosum var grandiflorum
  • Catasetum carunculatum
  • Catasetum darwinianum
  • Catasetum fuliginosum
  • Catasetum fuliginosum
  • Catasetum lansbergii
  • Myanthus callosus
  • Myanthus grandiflorus
  • Myanthus lansbergii



It is a medium sized, hot growing epiphytic species with fusiform, 10 cm long and 2.5 cm wide pseudobulbs enveloped basally by leaf sheaths and carrying 5, linear-lanceolate, medium green, plicate, 24 cm long and 4 cm wide leaves.
The Callous Catasetum blooms in the fall and winter on a basal, arching, 30 cm long, 10 to 15 flowered, racemose inflorescence with fragrant, inverted flowers arising on a mature pseudobulb. The male flowers are 3.5 cm in diameter. Coloration of peduncle and pedicels green (to dark maroon in darker-colored clones); sepals and petals light green (from light to dark green and brown in other clones); lip cream-colored to white (from light to dark green and brown in other clones); column darker cream-colored to yellow-green. The female flowers are not seen.
Some varieties of this orchid: var. carunculatum (lip shorter and wider than the other segments, toothed, with a yellow callus at the base), var. crenulatum (lip oblong-oval or almost fiddle-shaped, the margins, mainly in front, coarsely toothed, and the apex of the midlobe tridentate, and verrucose above), and var. typum (lip oblong-oval or trilobed, the margins noticeably notched, the midlobe smooth).



Cultural information should only be used as a guide, and should be to be adapted to suit you. Your physical location; where you grow your plants, how much time you have to devote to their care, and many other factors, will need to be taken into account. Only then can you decide on the cultural methods that best suit you and your plants.
Catasetum callosum are sun-loving plant (bright light) and needs a light level of 30000-60000 lux. This species can be grown under lights if sufficient light intensity can be provided, and the plant certainly can be summered outdoors if their moisture requirements can be met.



In their natural habitat, the climate is evenly hot, moist, and tropical. This climate is almost the same year-round, with high humidity at night, even in the dry season, which is relatively short. The nighttime temperatures rarely fall below 18°C, with daytime highs generally from 29 to 35°C. The important thing is to maintain evenly warm conditions, and for this orchid the closer the night minimum is to 21°C, the better the plants will respond.



The Callous Catasetum tolerate an environment with 40 - 60 % relative humidity during their growing season, but for optimal development of new growth and flowering, 70 % is recommended.
Substrate, growing media and repotting:
Catasetum callosum can be grown in pot, container or wooden basket with fir bark, osmunda, tree fern fiber, charcoal, and sphagnum, in various proportions or combined with still other ingredients such as sponge rock, perlite, leaf mold, peat, and bark screenings as substrate. This plant can also mounted on wood. This option presupposes that the plant is sufficiently strong, that it is not so large as to be unwieldy when hanging from its mount, that the grower can provide adequate humidity for it during the growing season, that the conversion to mounting is done at the very beginning of the growth cycle, and that the species is known to adapt readily to this cultural practice.
It is recommended to repot every year and never wait more than two years. The optimal time for potting or repotting is when new growth on a plant emerging from dormancy is about 5 cm tall and the nubs have developed into new roots that are reaching for support.
In its natural habitat it receives rainfall frequently even while dormant. Mounted, basket-grown, and unconventionally potted plant may be watered every sunny day during the growing season, provided conditions are such that they dry off relatively quickly. In the case of conventionally potted adult plants, it should not be necessary to water more than once or, at most, twice a week. This species like to dry out at least slightly between waterings.
Fertilize with an appropriate formulation at least every week during the growing season, or fertilize with a weak formula every time the plants are watered. It is important to begin regular applications of high-nitrogen fertilizer (such as 10-5-5) with a full range of trace elements. As the leaves begin to unfurl, and well before flowering, add a high-phosphorus formula to develop big, strong pseudobulbs capable of producing robust inflorescences. Any of the soluble products with a large second-digit number (for example, 3-12-6) constitute a good source of phosphorus.
Rest period:

When the Catasetum callosum plants are leafless and no new growths are visible, the grower must respect their state of dormancy. Watering frequency should be reduced during dormancy. Fertilization should stop completely during this period. In the springtime, at the beginning of the growth cycle, water should not be made regularly available for the newly developing roots until the new growth is at least 5 cm tall.





Awarded Exhibits:


Catasetum callosum 'SVO Black Lip'

2014-10 AM AOS 81 points
Fred Clarke


© Arthur Pnkers 2014

Plant Name: Catasetum callosum ‘SVO Black Lip’ AM/AOS 81 pts.


Natural Spread Horizontal: 8.0 cm Vertical: 7.5 cm
Dorsal Sepal
Width: 1.2 cm Length: 5.0 cm
Petal Width: 0.6 cm Length: 4.3 cm
Lateral Sepal (Synsepal): Width: 1.0 cm Length: 4.8 cm
Lip (Pouch): Width: 1.2 cm Length: 4.5 cm

Description: Thirty-two flowers of symmetric form and dark color, eight buds on three arching pendulous inflorescences; sepals and petals chestnut-brown veined darker; lip chartreuse, heavily stippled and overlaid dark brown, callus dark brown; column chestnut-brown, cream ventrally; substance firm; texture glossy.
Exhibitor: Fred Clarke





Catasetum callosum 'Baker's Chocolate Goblin'

2009-07 HCC AOS 79 points
Brent Baker


Catasetum callosum 'Jeanette'

2009-10 AM AOS 82 points
Philip MacIntyre


Catasetum callosum 'Orquivalle'

2005-01 AWD SCO    


Catasetum callosum 'Sunset Valley Orchids'

2004-08 AM AOS 80 points
Fred Clarke, Vista, California


Catasetum callosum f. album 'MAX'

2004-10 CHM AOS 85 points
MAJ Orchids, Orange Park, Florida


Catasetum callosum 'Stephen's Pride'

2003-06 HCC AOS 78 points
Wilton Guillory, Alexandria, Louisiana


Catasetum callosum var. album 'Sandy Stubbings'

2000-02 JC AOS 80 points
John Stubbings, Northbrook, Illinois


Catasetum callosum 'Milton Soloff'

1995-07 CHM AOS 83 points
Mark Andrew Margolis, Miami, Florida


Catasetum callosum 'Debbie's First'

1994-08 CHM AOS 81 points
Debra Bandy, Spring, Texas


Catasetum callosum 'Katiusca'

1990-08 CHM AOS 80 points
Eulalio Rodriquez, Barrio Rafael Urdenata, Calle 24 de Julio, No. 13 Aragua VEN





Additional Information:










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