Zamia

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Zamia
Zamia fairchildiana

Zamia fairchildiana

Systematics
Class : Cycadopsida
Order : Cycads (Cycadales)
Family : Zamiaceae
Subfamily : Zamioideae
Tribe : Zamieae
Genre : Zamia
Scientific name
Zamia
L.

Zamia is a genus of plants within the order of the cycads (Cycadales).

description

Illustration of Zamia angustifolia
Illustration from André: L'Illustration Horticole 20, 1873, pp. 133-134 by Zamia roezlii
Illustration of Zamia chigua
Illustration by Zamia skinneri
Illustration of Zamia pygmaea

Vegetative characteristics

The trunks usually form underground tubers without pronounced wood tissue. Some species form an above-ground trunk that can be 4 meters and more high. Three species have a strongly derived growth form: Zamia pseudoparasitica is an epiphyte on tree trunks and anchors itself with its roots . The other two, Zamia cremnophila and an undescribed species, grow on sandstone rocks and hold their roots in small crevices. Species with aboveground stems soon shed the leaf bases and cataphylls and then have a bare epidermis . In the species that grow in the rainforest, the trunk is soon covered with epiphytes.

The leaves are simply pinnate, long or short, upright, horizontal or hanging and very variable. Developing leaves are green, bronze, red, or purple. The petiole and rachis are unarmed or have sharp spines. The leaflets are stiff and leathery or soft and paper-like, the surface smooth, furrowed or ribbed, shiny or dull, the leaf margin entire, serrated or serrated. Zamia variegata has variegated leaves.

Generative characteristics

The female cones are very different depending on the species. The size ranges from 7.5 cm to 46 cm. The color of the sarcotesta ranges from yellow to orange and pink to red. Most species have no seed dormancy. The cones take 6 to 14 months to ripen and the growing seeds force the sporophylls apart. As long as immature, the Sarcotesta is inconspicuous. When the cone breaks open, the seeds quickly stop ripening and the sarcotesta becomes colored and soft. As far as investigated, the species are all pollinated by insects ( entomophilia ). The seeds may be spread by birds and rodents.

Male cones are less variable than the female ones. They are small, grow and pass quickly. In some tropical species, the many cones ripen one after the other, so that the pollen production takes a long time.

The chromosome numbers are 2n = 16-18, 21-28.

Occurrence and endangerment

The Zamia species have the broadest range of cycads in terms of locations. There are species in the rainforest, savannah , on stable coastal dunes, tidal swamps, and deserts, from sea level to altitudes of 2500 meters.

Many species are endangered due to their small area and increasing land use.

Systematics and distribution

The genus Zamia was by Carl Linnaeus in 1763 set up . The type species is Zamia pumila . Synonyms for Zamia L. are: Palmifolium Kuntze nom. superfl., Palma-filix Adans. nom. rej., Chigua D.W.Stev. , Aulacophyllum rule .

Zamia forms with the genus Microcyca the tribe Zamieae within the subfamily Zamioideae in the family Zamiaceae . Since Lindstrom 2009 the previous two species belong to the genus Chigua D.W.Stev. under the name Zamia restrepoi (DWStev.) A. Lindstr. also back to the genus Zamia .

The genus Zamia occurs in the Neotropic , but as one of the few cycads on both sides of the equator. The northern limit of the distribution lies in Georgia and Florida, the area extends over Mexico, the West Indies and Central America to South America to northern Chile, Bolivia and Brazil. It reaches the greatest biodiversity in Panama, Colombia and Cuba. There were 22 species in Mexico in 2009.

Whitelock lists 60 Zamia species in 2002 . After that many more species were first described. There are about 79 types of Zamia (as of 2018):

use

Zamia species are relatively seldom used as ornamental plants compared to other cycads . One reason is seen in their tropical distribution, in the moderate latitudes they can almost only be cultivated in greenhouses.

literature

  • Loran M. Whitelock: The Cycads. Timber Press, Portland OR 2002, ISBN 0-88192-522-5 , pp. 288 f.
  • AJ Lindstrom: Typification of some species names in Zamia L. (Zamiaceae), with an assessment of the status of Chigua D. Stev. In: Taxon , Volume 58, Issue 1, 2009, pp. 265-270.
  • R. Osborne, MA Calonje, KD Hill, L. Stanberg, DW Stevenson: The world list of cycads. Proceedings of the 8th International Conference on Cycad Biology (CYCAD 2008). Panama City, Panama, January 2008. In: Memoirs of the New York Botanical Garden , Volume 106, 2012, pp. 480-510.
  • Fernando Nicolalde-Morejón, Andrew P. Vovides, Dennis W. Stevenson: Taxonomic revision of Zamia in Mega-Mexico. In: Brittonia , Volume 61, Issue 4, 2009, pp. 301-335. JSTOR 40648244

Individual evidence

  1. Species Plantarum . 2nd edition, Volume 2, 1763, p. 1659 ( PDF )
  2. a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj ak al am an ao ap aq ar as at au av aw ax ay az ba bb bc bd be bf bg bh bi bj bk bl bm bn bo bp bq br bs bt bu bv bw bx by Rafaël Govaerts (Ed.): Zamia. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved May 5, 2019.
  3. AJ Lindstrom: typification of some species names in Zamia L. (Zamiaceae), with on assessment of the status of Chigua D. Stev. In: Taxon , Volume 58, Issue 1, 2009, pp. 265-270.
  4. a b c M. Calonje, DW Stevenson, R. Osborne: The World List of Cycads , online edition, 2013-2019. cycadlist.org .
  5. Loran M. Whitelock: The Cycads. 2002, pp. 290-344.

Web links

Commons : Zamia  - collection of images, videos and audio files
Wiktionary: Zamia  - explanations of meanings, word origins, synonyms, translations