Caularthron

Caularthron Raf. 1837 is a genus of epiphytic orchids with 4 species.

Description

These species have a wide range of color in their flowers in clusters that can be erect or pendulous.

Most are epiphytes. They have an alliance with Barkeria and Epidendrum. Some of its species are classified within the genus Diacrium. Stems are usually short.

The pseudobulbs are 6 to 30 cm long, ovoid, and clearly separated. Each pseudobulb develops one or two waxy, leathery leaves about 20 cm long.
The inflorescence is in a raceme and can be up to 30 cm long and bear about 8 flowers, which are pink, purple or white.

It is quite common for ant colonies to make their nests in the internodes of the pseudobulbs.

Distribution and habitat

Species of this genus are epiphytes and are widely distributed throughout the Caribbean, Central America, South America, and Trinidad.

Cultivation

Members of this genus are easily grown in cultivation and are drought resistant. The cultivation of each species requires specific conditions that correspond to those of its natural habitat. Many of them can be placed in plates, so their roots can receive drafts and withstand cycles of humidity or drought.

Species of Caularthron readily hybridize with species within the genus and with other close genera, such as Cattleya (x Laeliocattleya, more than 2,000 species), Brassavola, Bletia, Laelia, Rhyncholaelia, and Sophronitis. Most hybrid orchids belong to this category e.g. x Sophrolaeliocattleya, x Brassolaeliocattleya and a large number of other variations.

Taxonomy

The genus was described by Constantine Samuel Rafinesque and published in Flora Telluriana 2: 40–41. 1836[1837].

Etymology

The genus Caularthron (abbreviated Clrth.) its name comes from the Greek "kaulos" = "stem" and "arthron" = "together" in reference to its pseudobulbs that are grouped.

Species

• Caularthron amazonicum (Schltr.) H.G.Jones (1968)
• Caularthron bicornutum (Hook.) Raf. (1837) (Orchid Virgin)
• Caularthron bilamellatum (Rchb.f.) R.E.Schult. (1958)
• Caularthron kraenzlinianum H.G.Jones (1980

Intergeneric Hybrids

• Calaeonitis: Can (Caularthron x Laelia x Sophronitis)

• Caulaelia: Cll (Caularthron x Laelia).

• Laeliocatarthron: Lcr (Cattleya x Caularthron x Laelia).

• Nuccioara: Nuc (Cattleya x Caularthron x Laelia x Sophronitis).