Epidendrum rigidum
Epidendrum rigidum is an epiphytic reed-stemmed Epidendrum orchid common throughout the Neotroical lowlands, below 600 m. (The Fora of North America[1] 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.[2])
| Epidendrum rigidum | |
|---|---|
 | |
Scientific classification  | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Monocots |
| Order: | Asparagales |
| Family: | Orchidaceae |
| Subfamily: | Epidendroideae |
| Genus: | Epidendrum |
| Subgenus: | Epidendrum subg. Epidendrum |
| Section: | Epidendrum sect. Planifolia |
| Subsection: | Epidendrum subsect. Spathacea |
| Species: | E. rigidum |
| Binomial name | |
| Epidendrum rigidum | |
| Synonyms | |
|
Epidendrum pium Rchb.f. & Warm. | |
Description
E. rigidum has been placed in the subgenus E. subg Epidendrum Lindl. (1841)[3] 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.[4] 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.[5]
Homonymy
- Epidendrum rigidum Lodd. 1829 nom. illeg. is a synonym for E. ramosum Jacq. 1760
- Epidendrum rigidum var. angustisegmentum L.O.Williams 1946 is a synonym for E. angustisegmentum (L.O.Williams) Hágsater 1999
References
- Flora of North America 26(609)downloaded in October, 2009 from http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=242101582
- http://apps.kew.org/wcsp/
- H. G. Reichenbach item 307 of "ORCHIDES" in C. Müller: Walpers. Annales Botanices Systematicae VI(1861) p. 400
- C. Dodson & R. Vásquez "EPIDENDRUM RIGIDUM Jacq.", Plate 0334 in C. Dodson, Ed. Icones Plantarum Tropicarum, Series II Orchids of Bolivia Missouri Botanical Garden, St. Louis. 1989.
- page 252. Leonardo P. Felix and Marcelo Guerra: "Variation in chromosome number and the basic number of subfamily Epidendroideae (Orchidaceae)" Botanical Journal of the Linnean Society 163(2010)234-278, The Linnean Society of London
External links
Media related to Epidendrum rigidum at Wikimedia Commons
Data related to Epidendrum rigidum at Wikispecies- A photograph of the flowers may be found at The Internet Orchid Species Photo Encyclopedia
- 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