Epidendrum rigidum
Encyclopedia
Epidendrum rigidum is an epiphytic
reed-stemmed Epidendrum
orchid
common throughout the Neotroical lowlands, below 600 m. (The Fora of North America recognizes a distinct species, E. cardiophorum Schltr., which replaces E. rigidum in Mexico
and Central America
; Kew lists E. cardiophorum Schltr. as a synonym for E. rigidum.)
Lindl. (1841) because its sympodial stems do not thicken to form pseudobulbs, its stems are covered by the basal sheaths of its distichous leaves, and its peduncle
emerges from the apical leaf without being covered by any bract or sheath. The basal parts of the stems unite to form a creeping rhizome
; the upper parts grow to 20 cm long and can assume erect, horizontal, or hanging postures. The lathery ovate-oblong obtuse leaves are 3–8 cm long and apically bilobed. As with other members of E. subsect. Spathacea
Rchb.f. 1861, the racemose
inflorescence bears enlarged spathaceous floral bracts. The green, non-resupinate, fleshy flowers are partially covered by the large, dolabriform bracts. The ovate obtuse sepals are 5 mm long, with the lateral sepals larger than the dorsal sepal. The linear petals are also 5 mm long. As with other members of the genus Epidendrum
, the lip
is adnate to the column
to its apex. The lip is heart-shaped where it diverges from the column, ovate, and obtuse at the apex.
The diploid chromosome
number of E. rigidum has been determined as 2n = 40.
Epiphyte
An epiphyte is a plant that grows upon another plant non-parasitically or sometimes upon some other object , derives its moisture and nutrients from the air and rain and sometimes from debris accumulating around it, and is found in the temperate zone and in the...
reed-stemmed 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...
orchid
Orchidaceae
The Orchidaceae, commonly referred to as the orchid family, is a morphologically diverse and widespread family of monocots in the order Asparagales. Along with the Asteraceae, it is one of the two largest families of flowering plants, with between 21,950 and 26,049 currently accepted species,...
common throughout the Neotroical lowlands, below 600 m. (The Fora of North America recognizes a distinct species, E. cardiophorum Schltr., which replaces E. rigidum in Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
and Central America
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...
; Kew lists E. cardiophorum Schltr. as a synonym for E. rigidum.)
Description
E. rigidum has been placed in the subgenus E. subg EpidendrumEpidendrum subg. Epidendrum
The subgenus Epidendrum subg. Epidendrum was published as "Euepidendrum" in 1841 with the diagnosis "Caulis foliosus. Pedunculus brevis esquamatus...
Lindl. (1841) because its sympodial stems do not thicken to form pseudobulbs, its stems are covered by the basal sheaths of its distichous leaves, and its peduncle
Peduncle (botany)
In botany, a peduncle is a stem supporting an inflorescence, or after fecundation, an infructescence.The peduncle is a stem, usually green and without leaves, though sometimes colored or supporting small leaves...
emerges from the apical leaf without being covered by any bract or sheath. The basal parts of the stems unite to form a creeping rhizome
Rhizome
In botany and dendrology, a rhizome is a characteristically horizontal stem of a plant that is usually found underground, often sending out roots and shoots from its nodes...
; the upper parts grow to 20 cm long and can assume erect, horizontal, or hanging postures. The lathery ovate-oblong obtuse leaves are 3–8 cm long and apically bilobed. As with other members of E. subsect. Spathacea
Epidendrum subsect. Spathacea
Epidendrum subsect. Spathacea Rchb.f. is a subsection of the section E. sect. Planifolia Rchb.f. 1861 of the subgenus E. subg. Epidendrum Lindl. 1841 of the genus Epidendrum Lindl. of the Orchidaceae...
Rchb.f. 1861, the racemose
Raceme
A raceme is a type of inflorescence that is unbranched and indeterminate and bears pedicellate flowers — flowers having short floral stalks called pedicels — along the axis. In botany, axis means a shoot, in this case one bearing the flowers. In a raceme, the oldest flowers are borne...
inflorescence bears enlarged spathaceous floral bracts. The green, non-resupinate, fleshy flowers are partially covered by the large, dolabriform bracts. The ovate obtuse sepals are 5 mm long, with the lateral sepals larger than the dorsal sepal. The linear petals are also 5 mm long. As with other members of the genus 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...
, the 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:...
is adnate 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 is heart-shaped where it diverges from the column, ovate, and obtuse at the apex.
The diploid chromosome
Chromosome
A chromosome is an organized structure of DNA and protein found in cells. It is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions.Chromosomes...
number of E. rigidum has been determined as 2n = 40.
Homonymy
- Epidendrum rigidum Lodd. 1829 nom. illeg. is a synonym for E. ramosumEpidendrum ramosumEpidendrum ramosum is a neotropical species of reed-stemmed Epidendrum orchid which grows both epiphytically and terrestrially at altitudes near 1 km.-Description:...
Jacq. 1760 - Epidendrum rigidum var. angustisegmentum L.O.Williams 1946 is a synonym for E. angustisegmentum (L.O.Williams) Hágsater 1999
External links
- A photograph of the flowers may be found at http://www.orchidspecies.com/epirigidum.htm
- Photographs of the flowering plant and leaves may be found at http://www.cybertruffle.org.uk/vinales/eng/epidendrum_rigidum.htm
- http://titanarum.uconn.edu/199100202.html