Envoy at 11:37, 21 October 2007

2007-10-21T11:37:13Z

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{{Taxobox
| color = lightgreen
| name = ''Chigua''
| regnum = [[Plant]]ae
| divisio = [[Cycad]]ophyta
| classis = [[Cycad]]opsida
| ordo = [[Cycad]]ales
| familia = [[Zamiaceae]]
| genus = '''''Chigua'''''
| genus_authority = [[Dennis Stevenson|Stevenson]]
| subdivision_ranks = Species
| subdivision =
*''[[Chigua bernalii]]''
*''[[Chigua restrepoi]]''
}}

'''''Chigua''''' is a genus of [[cycad]]s in the family [[Zamiaceae]] containing two species, endemic to small areas in northwestern [[Colombia]]. Described by botanist [[Dennis Stevenson]] in [[1990]], it is the most recently named genus. Both species are listed as [[Critically Endangered]] by the [[IUCN Red List]]. The genus name comes from a [[Spanish language|Spanish]] transliteration of the common name given to cycads by the indigenous peoples of Colombia. The species are found in wet lowland [[rainforest]]s at 100-200 m altitude.

Plants have a subterranean globose stem. The [[leaf|leaves]] emerge singly and are straight, oblong, and pinnately compound. The petiole and [[rachis]] have spines. [[Leaflet]]s are opposite, lanceolate, and jointed at the base. They have a toothed margin with a distinct [[midrib]] and forking parallel side veins. Male cones are cylindrical and covered in short hairs. They are held on long erect stalks and have hexagonal [[sporophyll]]s. Female cones are broadly cylindrical and hairy, held on very long [[peduncle]]s two to three times the length of the cone. The female sporophylls are also hexagonal and have distinct bumps. The elliptical seeds are pink or red in color.

''Chigua'' is very closely related to the genus ''[[Zamia]]'' . ''C. restrepoi'' was collected as early as [[1918]] by [[Francis Pennell]], but the new species was placed in ''Zamia''. It was not collected again until [[1986]], and two subsequent collections in [[1987]] and [[1988]] became the basis for the establishment of a new genus. Because the genus has only been collected four times, there is little known about its conservation problems. The population sizes for the species are unknown, and nothing is known about the cones or seeds of ''C. bernalii'', which is only known from the 1986 collection. Because political conflict in Colombia has made travelling dangerous there, the genus is unlikely to be well known for a while. Cattle [[grazing]], [[mining]], and [[oil exploration]] have threatened the habitat in the region.

==References==
*Jones, David L. ''Cycads of the World: Ancient Plants in Today's Landscape''. Washington, D.C.: Smithsonian Institution Press, 2002. ISBN 1-58834-043-0.
*[http://plantnet.rbgsyd.gov.au/cgi-bin/taxon.pl?name=Chigua ''Chigua'' in The Cycad Pages]
*[http://www.horticulturalconsultants.com/cycad/chigua.html Horticultural Consultants, Inc. – ''Chigua'']

[[Category:Cycads]]

Chigua - Revision history

Envoy at 11:37, 21 October 2007