Epidendrum radicans
Encyclopedia
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
, E. ibaguense
, E. imatophyllum
, E. incisum
, E. schomburgkii
, E. secundum
, and E. xanthinum, among others. The diagnostic characteristic of E. radicans is its tendency to sprout roots all along the length of the stem; other crucifix orchids only produce roots near the base. Additionally, E. radicans flowers are resupinate, unlike the members of the Epidendrum secundum complex, E. fulgens, and many other crucifix orchids. E. radicans also differs from E. secundum by bearing no nectar in the flower.
, is a sympodial orchid which grows stems which do not swell into pseudobulbs and are covered with imbricating sheaths, produces a terminal inflorescence covered at its base by close imbricating sheaths, and produces a lip
adnate
to the column
to its apex. The lip of E. radicans is trilobate, as with the other members of section Schistochila
, with the lacerate lobes which are typical of the subsections Carinata
and Tuberculata
. E. radicans differs from the other lacerate Schistochila by producing roots from most of the stem.
Epidendrum radicans (or perhaps E. ibaguense) seeds are quite small, at 320 (or perhaps 167) seeds per mg.
The chromosome number of an individual collected in Ecuador has been determined as 2n = 60. This increases the diversity of reported chromosome numbers for E. radicans by disagreeing with other values: 2n = 40, 2n = 57, 2n = 62, and 2n = 64
) data, and somatic chromosome number for 30 individuals in three of the thirteen recognized species of E. subsect. Tuberculata and twenty individuals in eleven of the twelve recognized species of E. subsect. Carinata, including E. radicans, has suggested that perhaps E. subsect. Carinata
should be replaced with three subsections: an "Atlantic" subsection, an "Andean" subsection, and a monotypic subsection for E. radicans.
spp.) that are unrelated but ecologically similar. Species within this group share pollinators as well as habitat, and are believed to exhibit what is known as convergent evolution
, where unrelated species "converge" upon similar physical characteristics as a result of similar evolutionary pressures. Paulette Bierzychudek studied pollinator behavior in the apparent complex consisting of E. radicans, Asclepias curassavicia, and Lantana camara
, but could not find clear evidence that floral mimicry was affecting pollination rates for any of the three species.
Central America
Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...
. A crucifix orchid, it is often confused with many other members of the section 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...
, including E. calanthe, 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. denticulatum
Epidendrum denticulatum
Epidendrum denticulatum, one of the crucifix orchids, is a reed stemmed species which, at least in herbarium specimens, is frequently confused with E. secundum Jacq....
, E. erectum, 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...
, 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...
, E. imatophyllum
Epidendrum flexuosum
Epidendrum flexuosum, a reed-stemmed Epidendrum common at mid-altitudes in Central America, is a species of orchid commonly called Epidendrum imatophyllum. It grows exposed to intense sunlight in the forest canopy, particularly on Guava species...
, E. incisum
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...
, E. schomburgkii
Epidendrum macrocarpum
Epidendrum macrocarpum, commonly known as Epidendrum schomburgkii, is a species of orchid in the genus Epidendrum, and the largest-flowering crucifix orchid species...
, 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...
, and E. xanthinum, among others. The diagnostic characteristic of E. radicans is its tendency to sprout roots all along the length of the stem; other crucifix orchids only produce roots near the base. Additionally, E. radicans flowers are resupinate, unlike the members of the Epidendrum secundum complex, E. fulgens, and many other crucifix orchids. E. radicans also differs from E. secundum by bearing no nectar in the flower.
Description
E. radicans, like other members of subgenus AmphiglottiumEpidendrum subg. Amphiglottium
Epidendrum subg. Amphiglottium Lindl. 1841 is a subgenus of reed-stemmed Epidendrums, distinguished by an apical inflorescence with the peduncle covered from its base with close imbricating sheaths and by a lip that is adnate to the column to its apex.Reichenbach published three sections in this...
, is a sympodial orchid which grows stems which do not swell into pseudobulbs and are covered with imbricating sheaths, produces a terminal inflorescence covered at its base by close imbricating sheaths, and produces a lip
Labellum
Labellum is the Latin diminutive of labium, meaning lip. These are anatomical terms used descriptively in biology, for example in Entomology and botany.-Botany:...
adnate
Adnation
Adnation in plants is the "union of unlike parts; organically united or fused with another dissimilar part, e.g. an ovary to a calyx tube, or stamens to petals". This is in contrast to connation, the fusion of similar organs....
to the column
Column (botany)
The column, or technically the gynostemium, is a reproductive structure that can be found in several plant families: Aristolochiaceae, Orchidaceae, and Stylidiaceae....
to its apex. The lip of E. radicans is trilobate, as with the other members of section 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...
, with the lacerate lobes which are typical of the subsections Carinata
Epidendrum subsect. Carinata
Epidendrum subsect. Carinata Rchb.f. is a subsection of the section E. sect. Schistochila Rchb.f. of the subgenus E. subg. Amphiglottium Lindl. of the genus Epidendrum of the Orchidaceae...
and Tuberculata
Epidendrum subsect. Tuberculata
Epidendrum subsect. Tuberculata is a subsection of the section Schistochila of the subgenus Amphiglottium Lindl. of the genus Epidendrum of the Orchidaceae. This subsection differs from the subsection Integra in that the margins of the trilobate lip are dentate or lacerate...
. E. radicans differs from the other lacerate Schistochila by producing roots from most of the stem.
Epidendrum radicans (or perhaps E. ibaguense) seeds are quite small, at 320 (or perhaps 167) seeds per mg.
The chromosome number of an individual collected in Ecuador has been determined as 2n = 60. This increases the diversity of reported chromosome numbers for E. radicans by disagreeing with other values: 2n = 40, 2n = 57, 2n = 62, and 2n = 64
Taxonomic placement
A biochemical examination (Pinheiro & al., 2009) of the lacerate Schistochila subsections encompassing plastid nucleotide sequence data from the trnL—trnF regions, Amplified Fragment Length Polyorphism (AFLPAmplified fragment length polymorphism
Amplified Fragment Length Polymorphism PCR is a PCR-based tool used in genetics research, DNA fingerprinting, and in the practice of genetic engineering. Developed in the early 1990s by Keygene, AFLP uses restriction enzymes to digest genomic DNA, followed by ligation of adaptors to the sticky...
) data, and somatic chromosome number for 30 individuals in three of the thirteen recognized species of E. subsect. Tuberculata and twenty individuals in eleven of the twelve recognized species of E. subsect. Carinata, including E. radicans, has suggested that perhaps E. subsect. Carinata
Epidendrum subsect. Carinata
Epidendrum subsect. Carinata Rchb.f. is a subsection of the section E. sect. Schistochila Rchb.f. of the subgenus E. subg. Amphiglottium Lindl. of the genus Epidendrum of the Orchidaceae...
should be replaced with three subsections: an "Atlantic" subsection, an "Andean" subsection, and a monotypic subsection for E. radicans.
Ecology
E. radicans is part of a complex of several orange-flowered, weedy species (including AsclepiasAsclepias
Asclepias L. , the milkweeds, is a genus of herbaceous perennial, dicotyledonous plants that contains over 140 known species...
spp.) that are unrelated but ecologically similar. Species within this group share pollinators as well as habitat, and are believed to exhibit what is known as convergent evolution
Convergent evolution
Convergent evolution describes the acquisition of the same biological trait in unrelated lineages.The wing is a classic example of convergent evolution in action. Although their last common ancestor did not have wings, both birds and bats do, and are capable of powered flight. The wings are...
, where unrelated species "converge" upon similar physical characteristics as a result of similar evolutionary pressures. Paulette Bierzychudek studied pollinator behavior in the apparent complex consisting of E. radicans, Asclepias curassavicia, and Lantana camara
Lantana camara
Lantana camara, also known as Spanish Flag or West Indian Lantana, is a species of flowering plant in the verbena family, Verbenaceae, that is native to the American tropics. It has been introduced into other parts of the world as an ornamental plant and is considered an invasive species in many...
, but could not find clear evidence that floral mimicry was affecting pollination rates for any of the three species.