Epidendrum denticulatum
Encyclopedia
Epidendrum denticulatum, one of the crucifix orchids, is a reed stemmed species which, at least in herbarium specimens, is frequently confused with E. secundum
Epidendrum secundum
Epidendrum secundum, one of the crucifix orchids, is a poorly understood reed stemmed species, which Dressler describes as "the Epidendrum secundum complex." According to Dressler, there are dozens of varieties, some of which appear to deserve species rank...

Jacq.

Like E. secundum
Epidendrum secundum
Epidendrum secundum, one of the crucifix orchids, is a poorly understood reed stemmed species, which Dressler describes as "the Epidendrum secundum complex." According to Dressler, there are dozens of varieties, some of which appear to deserve species rank...

, the flowers of E. denticulatum are non-resupinate and are born in a congested raceme at the end of a long spike. Like all crucifix orchids, the lip is adnate to the column and bears three lobes, producing the effect of a cross.

Occurrence

Epidendrum denticulatum is grows in tropical dry forests of the Serra do Mar
Serra do Mar
Serra do Mar is a 1,500 km long system of mountain ranges and escarpments in Southeastern Brazil, which runs in parallel to the Atlantic Ocean coast from the state of Espírito Santo to southern Santa Catarina, although some include Serra Geral in the Serra do Mar, in which case this range...

 in Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...

, extending from the coastal states of Rio Grande do Sul
Rio Grande do Sul
Rio Grande do Sul is the southernmost state in Brazil, and the state with the fifth highest Human Development Index in the country. In this state is located the southernmost city in the country, Chuí, on the border with Uruguay. In the region of Bento Gonçalves and Caxias do Sul, the largest wine...

, to Pernambuco
Pernambuco
Pernambuco is a state of Brazil, located in the Northeast region of the country. To the north are the states of Paraíba and Ceará, to the west is Piauí, to the south are Alagoas and Bahia, and to the east is the Atlantic Ocean. There are about of beaches, some of the most beautiful in the...

, as well as in the forests of Minas Gerais
Minas Gerais
Minas Gerais is one of the 26 states of Brazil, of which it is the second most populous, the third richest, and the fourth largest in area. Minas Gerais is the Brazilian state with the largest number of Presidents of Brazil, the current one, Dilma Rousseff, being one of them. The capital is the...

, at altitudes ranging from 0.5 to 1.4 km. The plant grows both terrestrially and epiphytically. It is most commonly found living among low bushes and at the edge of roads, occasionally forming large tussocks that can measure more than 5 m2.

Although there are several references stating that E. denticulatum grows at low altitudes near the sea shore these may be the result of confusing E. denticulatum with other members of the Schistochila Carinata subsection of Epidendrum
Epidendrum
Epidendrum , abbreviated Epi in horticultural trade, is a large neotropical genus of the orchid family. With more than 1,100 species, some authors describe it as a mega-genus. The genus name refers to its epiphytic growth habit...

, such as (e.g.) E. cinnabarinum
Epidendrum cinnabarinum
Epidendrum cinnabarinum, is a terrestrial reed-stemmed Epidendrum, discovered by the German collector Philipp Salzmann in Bahia, close to Salvador, and published by John Lindley in 1831. The specific epithet refers to the vermilion flowers. E. cinnabarinum is similar to E. fulgens and E...

, E. fulgens
Epidendrum fulgens
Epidendrum fulgens is a crucifix orchid native to Brazil. Like E. secundum, with which it has been found to hybridize in habitats disturbed by human activity, E. fulgens flowers are non-resupinate and are born in a congested racime at the end of a long spike...

, and E. puniceoluteum.

Description

This sympodial
Sympodial
Sympodial means "with conjoined feet", and in biology is often used to refer to the outward morphology or mode of growth of organisms.-In botany:...

 reed-stemmed Epidendrum displays a pseudomonopodial
Monopodial
Vascular plants with monopodial growth habits grow upward from a single point. They add leaves to the apex each year and the stem grows longer accordingly...

 habit: an individual stem (to 4 mm in diameter) will grow continuously at the tip for some time, before producing a bloom spike. Nevertheless, the flowers come from the top of the stem (halting its upward growth), and new stems start from buds at the base of the old stems, thus making the plant sympodial
Sympodial
Sympodial means "with conjoined feet", and in biology is often used to refer to the outward morphology or mode of growth of organisms.-In botany:...

, like the rest of the subtribe Laeliinae
Laeliinae
Laeliinae is a Neotropical subtribe including 40 orchid genera, such as Brassavola, Laelia, Sophronitis, and Cattleya. The genus Epidendrum is the largest within this subtribe, containing about 1500 species...

. Less than ideal lighting will encourage the formation of numerous keiki
Keiki
Keiki is the Hawaiian word for "baby" or "child", literally meaning "the little one". In horticulture, it refers to a plant produced asexually by an orchid plant, usually used when referring to Dendrobium, Epidendrum , and Phalaenopsis orchids...

s producing a tangled mass of shoots and roots high up the plant. However, full sunlight will cause most growths to start near the base of old growths, leading to a shorter and "tidier" plant.

The long, thin (3 mm or less thick) roots of E. denticulatum are covered with spongy velamen
Velamen
Velamen is a spongy, multiple epidermis that covers the roots of some epiphytic or semi-epiphytic plants, such as orchid and Clivia species....

, and extend through the air into the ground.

The alternate, coriaceous leaves measure up to 9 cm long and 2 cm wide.

The inflorescence is a terminal raceme, filling a globular space that can measure more than 30 cm and can inclulde up to a hundred flowers, with some ten to thirty open simultaneously. A single inflorescence can remain in bloom for up to a year. The flowers may be white, cream, yellow, or orange, but are more commonly lavender. Each flower measures about 2 cm in diameter. The two petals and three sepals are similar and oval, measuring about 11 mm long by 5 mm wide, each of these perianth segment separated from the next by an angle close to 60°. As in all Epidendrum
Epidendrum
Epidendrum , abbreviated Epi in horticultural trade, is a large neotropical genus of the orchid family. With more than 1,100 species, some authors describe it as a mega-genus. The genus name refers to its epiphytic growth habit...

flowers, the lip is adnate to the column to the end. As in the other members of the section E. sect. Schistochila
Epidendrum sect. Schistochila
Epidendrum sect. Schistochila Rchb.f. is a section of the subgenus E. subg. Amphiglottium Lindl. of the Genus Epidendrum of the Orchidaceae...

, the lip is divided into three lobes. This species is named for the tooth-like serrated margins of the three labial lobes.

The chromosome number of Epidendrum denticulatum has been determined to be 2n = 40.

Distinguishing characteristics

Perhaps the most noticeable difference between E. denticulatum and E. secundum
Epidendrum secundum
Epidendrum secundum, one of the crucifix orchids, is a poorly understood reed stemmed species, which Dressler describes as "the Epidendrum secundum complex." According to Dressler, there are dozens of varieties, some of which appear to deserve species rank...

is the callus: E. denticulatum has two small calli near the column and a long keel beginning between them; E. secundum
Epidendrum secundum
Epidendrum secundum, one of the crucifix orchids, is a poorly understood reed stemmed species, which Dressler describes as "the Epidendrum secundum complex." According to Dressler, there are dozens of varieties, some of which appear to deserve species rank...

has a single, much larger callus positioned in front of the column.

To assist in distinguishing herbarium specimens, Pinheiro and Barros (2007) undertook a statistical examination of flowers growing under cultivation in São Paulo, Brazil. They found that E. denticulatum had a column length of 7–8 mm, and a labellum with a width of 11.7–13.4mm, a lateral lobe length of 4.9–5.7 mm (measured from the edge of the callus to the end of the lateral lobe), and a central lobe length of 2.2–3.2 mm (from the point where the lateral and central lobes meet), as opposed to E. secundum
Epidendrum secundum
Epidendrum secundum, one of the crucifix orchids, is a poorly understood reed stemmed species, which Dressler describes as "the Epidendrum secundum complex." According to Dressler, there are dozens of varieties, some of which appear to deserve species rank...

, which had a column length of 4.7–6.2 mm, and a lip with a width of 8.6–7.2 mm, a lateral lobe length of 2.5–3.8 mm, and a central lobe length of 3–4 mm.

According to Almeida & Figueiredo (2003), E. denticulatum Jacq. produces nectar "on the petioles of buds, flowers, and fruits," but not on the flowers. According to Pansarin & Amaral (2008), E. secundum
Epidendrum secundum
Epidendrum secundum, one of the crucifix orchids, is a poorly understood reed stemmed species, which Dressler describes as "the Epidendrum secundum complex." According to Dressler, there are dozens of varieties, some of which appear to deserve species rank...

has a nectary at the back of the tube formed by the flower lip and column.

E. denticulatum is distinguishable from the very similar but resupinate-flowered E. ibaguense
Epidendrum ibaguense
Epidendrum ibaguense is a species of epiphytic orchid of the genus Epidendrum which occurs in Trinidad, French Guyana, Venezuela, Colombia and Northern Brazil.There is a good article on this species in the Português Wikipedia...

and E. radicans
Epidendrum radicans
This ground-rooting orchid is a common roadside weed at middle elevations in Central America. A crucifix orchid, it is often confused with many other members of the section Schistochila, including E. calanthe, E. cinnabarinum, E. denticulatum, E. erectum, E. fulgens,...

by its non-resupinate flowers.

History

E. denticulatum was described by John Barbosa Rodrigues in 1881 from a plant with lavender flowers and white and yellow calli found blooming in the month of March on a tree in the forest near Joinville, Santa Catarina.

External links

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