Ceratozamia
Encyclopedia
Ceratozamia is a genus of New World cycad
s in the family Zamiaceae
. The genus contains 16-18 currently living species and one or two fossil species. Most species are endemic to mountainous areas of Mexico
, while C. robusta extends into the mountains of Guatemala
and Belize
. The genus name comes from the Greek
ceras, meaning horn, which refers to the paired, spreading horny projections on the male and female sporophyll
s of all species. Many species have extremely limited ranges, and almost all described species are listed as vulnerable, endangered, or critically endangered by the IUCN Red List
. Illegal plant poaching
has posed a major threat to Ceratozamia species.
The plants are dioecious
, with a globose or cylindrical stem, rarely dichotomously branched, that may be underground or emergent. Several species produce basal shoot
s or suckers. The leaves
are pinnately compound, straight, and spirally arranged. Leaf bases are usually deciduous but sometimes persistent. The petioles
and rachis
often have spines, though there may be very few to none. Leaflets are simple, entire, and articulate at the base, with parallel side veins and no distinct central vein. Male cones are cylindrical, upright, hairy, and stalked. Female cones are stalked or sessile, erect, and have short hairs. Seeds are oblong or elliptical, with a fleshy whitish outer coat.
Most species inhabit mountainous areas at 800-1000 m elevation, on sheltered slopes in moist forests. These forests range from tropical rainforest
s that are always wet, to pine-oak forests with alternating wet and dry seasons. There is a noticeable correlation between characteristics of species and the wetness or dryness of the habitat. Species with broad, thin leaflets live in wet habitats, and species with narrow, thick leaflets live in climates with wet and dry seasons.
No formal classification of the genus currently exists, but studies by researchers have shown that there are two major groups within the genus. The first group contains seven described species. Species in this group have small cones and thin, broad, asymmetrical leaflets that taper gradually toward the base. Species of the second group have cones that are small to large. Leaflets are narrow, thin to thick in texture, symmetrical, and do not taper toward the base. This group contains nine species.
Group 1:
Group 2:
In addition, several species have only been very recently discovered and are not yet formally recognised. These include Ceratozamia mirandai and Ceratozamia zoquensis. There are two described fossil species, Ceratozamia hofmannii and Ceratozamia wrightii, but the former may actually be a monocotyledon
. C. wrightii is the first evidence of the genus in the fossil record, with leaf fragments of the species found in Eocene
deposits on Kupreanof Island
in Alaska
. This would support the hypothesis that there was a subtropical climate in northern areas during the Tertiary
.
Cycad
Cycads are seed plants typically characterized by a stout and woody trunk with a crown of large, hard and stiff, evergreen leaves. They usually have pinnate leaves. The individual plants are either all male or all female . Cycads vary in size from having a trunk that is only a few centimeters...
s in the family Zamiaceae
Zamiaceae
The Zamiaceae are a family of cycads that are superficially palm or fern-like. They are divided into two subfamilies with eight genera and about 150 species in the tropical and warm temperate regions of Africa, Australia and North and South America....
. The genus contains 16-18 currently living species and one or two fossil species. Most species are endemic to mountainous areas of 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...
, while C. robusta extends into the mountains of Guatemala
Guatemala
Guatemala is a country in Central America bordered by Mexico to the north and west, the Pacific Ocean to the southwest, Belize to the northeast, the Caribbean to the east, and Honduras and El Salvador to the southeast...
and Belize
Belize
Belize is a constitutional monarchy and the northernmost country in Central America. Belize has a diverse society, comprising many cultures and languages. Even though Kriol and Spanish are spoken among the population, Belize is the only country in Central America where English is the official...
. The genus name comes from the Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
ceras, meaning horn, which refers to the paired, spreading horny projections on the male and female sporophyll
Sporophyll
A sporophyll is a leaf that bears sporangia. Both microphylls and megaphylls can be sporophylls. In heterosporous plants, sporophylls bear either megasporangia , or microsporangia...
s of all species. Many species have extremely limited ranges, and almost all described species are listed as vulnerable, endangered, or critically endangered by the IUCN Red List
IUCN Red List
The IUCN Red List of Threatened Species , founded in 1963, is the world's most comprehensive inventory of the global conservation status of biological species. The International Union for Conservation of Nature is the world's main authority on the conservation status of species...
. Illegal plant poaching
Poaching
Poaching is the illegal taking of wild plants or animals contrary to local and international conservation and wildlife management laws. Violations of hunting laws and regulations are normally punishable by law and, collectively, such violations are known as poaching.It may be illegal and in...
has posed a major threat to Ceratozamia species.
The plants are dioecious
Dioecious
Dioecy is the property of a group of biological organisms that have males and females, but not members that have organs of both sexes at the same time. I.e., those whose individual members can usually produce only one type of gamete; each individual organism is thus distinctly female or male...
, with a globose or cylindrical stem, rarely dichotomously branched, that may be underground or emergent. Several species produce basal shoot
Basal shoot
A basal shoot, root sprout, adventitious shoot, water sprout or sucker is a shoot or cane which grows from a bud at the base of a tree or shrub or from its roots. This shoot then becomes, or takes the form of, a singular plant. A plant that produces suckers is referred to as surculose...
s or suckers. The leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
are pinnately compound, straight, and spirally arranged. Leaf bases are usually deciduous but sometimes persistent. The petioles
Petiole (botany)
In botany, the petiole is the stalk attaching the leaf blade to the stem. The petiole usually has the same internal structure as the stem. Outgrowths appearing on each side of the petiole are called stipules. Leaves lacking a petiole are called sessile, or clasping when they partly surround the...
and rachis
Rachis
Rachis is a biological term for a main axis or "shaft".-In zoology:In vertebrates a rachis can refer to the series of articulated vertebrae, which encase the spinal cord. In this case the rachis usually form the supporting axis of the body and is then called the spine or vertebral column...
often have spines, though there may be very few to none. Leaflets are simple, entire, and articulate at the base, with parallel side veins and no distinct central vein. Male cones are cylindrical, upright, hairy, and stalked. Female cones are stalked or sessile, erect, and have short hairs. Seeds are oblong or elliptical, with a fleshy whitish outer coat.
Most species inhabit mountainous areas at 800-1000 m elevation, on sheltered slopes in moist forests. These forests range from tropical rainforest
Tropical rainforest
A tropical rainforest is an ecosystem type that occurs roughly within the latitudes 28 degrees north or south of the equator . This ecosystem experiences high average temperatures and a significant amount of rainfall...
s that are always wet, to pine-oak forests with alternating wet and dry seasons. There is a noticeable correlation between characteristics of species and the wetness or dryness of the habitat. Species with broad, thin leaflets live in wet habitats, and species with narrow, thick leaflets live in climates with wet and dry seasons.
No formal classification of the genus currently exists, but studies by researchers have shown that there are two major groups within the genus. The first group contains seven described species. Species in this group have small cones and thin, broad, asymmetrical leaflets that taper gradually toward the base. Species of the second group have cones that are small to large. Leaflets are narrow, thin to thick in texture, symmetrical, and do not taper toward the base. This group contains nine species.
Group 1:
- Ceratozamia euryphyllidiaCeratozamia euryphyllidiaCeratozamia euryphyllidia is a species of plant in the Zamiaceae family. It is found in Guatemala and Mexico. It is threatened by habitat loss.-Source:* Donaldson, J.S. 2003. . Downloaded on 21 August 2007....
- Ceratozamia hildaeCeratozamia hildaeCeratozamia hildae, commonly known as the Bamboo Cycad, is a species of cycad in the Zamiaceae family that is endemic to Mexico. It is native to the Huasteca Potosina of Querétaro and San Luis Potosí, near the Santa Maria River. C. hildae inhabits deciduous oak woodlands at elevations of . It is...
- Ceratozamia latifoliaCeratozamia latifoliaCeratozamia latifolia is a species of cycad in the Zamiaceae family that is endemic to Querétaro, Hidalgo and San Luis Potosí in Mexico. It inhabits cloud zone oak forests in the Sierra Madre Oriental....
- Ceratozamia microstrobilaCeratozamia microstrobilaCeratozamia microstrobila is a species of plant in the Zamiaceae family. It is endemic to Mexico. It is threatened by habitat loss.-Source:* Donaldson, J.S. 2003. . Downloaded on 21 August 2007....
- Ceratozamia miquelianaCeratozamia miquelianaCeratozamia miqueliana is a species of plant in the Zamiaceae family. It is endemic to Mexico. Its natural habitat is subtropical or tropical moist lowland forests. It is threatened by habitat loss.-Source:...
- Ceratozamia morettiiCeratozamia morettiiCeratozamia morettii is a species of plant in the Zamiaceae family. It is endemic to Mexico. Its natural habitat is subtropical or tropical moist montanes. It is threatened by habitat loss.-Source:...
- Ceratozamia whitelockianaCeratozamia whitelockianaCeratozamia whitelockiana is a species of plant in the Zamiaceae family. It is endemic to Mexico. Its natural habitat is subtropical or tropical moist montanes. It is threatened by habitat loss.-Source:...
Group 2:
- Ceratozamia alvareziiCeratozamia alvareziiCeratozamia alvarezii is a species of plant in the Zamiaceae family. It is endemic to Mexico. It is threatened by habitat loss.-Source:* Donaldson, J.S. 2003. . Downloaded on 21 August 2007....
- Ceratozamia kuesterianaCeratozamia kuesterianaCeratozamia kuesteriana is a species of cycad in the Zamiaceae family that is endemic to the Sierra Madre Oriental of Mexico.It is restricted to steep slopes in pine-oak dominated cloud forests between Gómez Farías and Tula in southern Tamaulipas....
- Ceratozamia matudaeCeratozamia matudaeCeratozamia matudae is a species of plant in the Zamiaceae family. It is found in Guatemala and Mexico. Its natural habitat is subtropical or tropical moist montanes.-Source:* Donaldson, J.S. 2003. . Downloaded on 21 August 2007....
- Ceratozamia mexicanaCeratozamia mexicanaCeratozamia mexicana is a species of plant in the Zamiaceae family. It is endemic to Mexico. Its natural habitats are subtropical or tropical moist lowland forests and subtropical or tropical moist montanes. It is threatened by habitat loss.-Source:...
- Ceratozamia mixeorumCeratozamia mixeorumCeratozamia mixeorum is a species of plant in the Zamiaceae family. It is endemic to Mexico. Its natural habitat is subtropical or tropical moist montanes.-Source:* Donaldson, J.S. 2003. . Downloaded on 21 August 2007....
- Ceratozamia norstogiiCeratozamia norstogiiCeratozamia norstogii is a species of plant in the Zamiaceae family. It is endemic to Mexico. It is threatened by habitat loss.-Source:* Donaldson, J.S. 2003. . Downloaded on 21 August 2007....
- Ceratozamia robustaCeratozamia robustaCeratozamia robusta is a species of plant in the Zamiaceae family. It is found in Belize, Guatemala, and Mexico. Its natural habitat is subtropical or tropical moist lowland forests. It is threatened by habitat loss.-Source:...
- Ceratozamia sabatoiCeratozamia sabatoiCeratozamia sabatoi is a species of plant in the Zamiaceae family. It is endemic to Mexico. It is threatened by habitat loss.-Source:* Donaldson, J.S. 2003. . Downloaded on 21 August 2007....
- Ceratozamia zaragozaeCeratozamia zaragozaeCeratozamia zaragozae is a species of plant in the Zamiaceae family. It is endemic to Mexico. It is threatened by habitat loss.-Source:* Donaldson, J.S. 2003. . Downloaded on 21 August 2007....
In addition, several species have only been very recently discovered and are not yet formally recognised. These include Ceratozamia mirandai and Ceratozamia zoquensis. There are two described fossil species, Ceratozamia hofmannii and Ceratozamia wrightii, but the former may actually be a monocotyledon
Monocotyledon
Monocotyledons, also known as monocots, are one of two major groups of flowering plants that are traditionally recognized, the other being dicotyledons, or dicots. Monocot seedlings typically have one cotyledon , in contrast to the two cotyledons typical of dicots...
. C. wrightii is the first evidence of the genus in the fossil record, with leaf fragments of the species found in Eocene
Eocene
The Eocene Epoch, lasting from about 56 to 34 million years ago , is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era. The Eocene spans the time from the end of the Palaeocene Epoch to the beginning of the Oligocene Epoch. The start of the...
deposits on Kupreanof Island
Kupreanof Island
Kupreanof Island is an island in the Alexander Archipelago in southeastern Alaska. The island is long and wide with a total land area is , making it the 13th largest island in the United States and the 170th largest island in the world. The Lindenberg Peninsula, on the southeast side of the...
in Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
. This would support the hypothesis that there was a subtropical climate in northern areas during the Tertiary
Tertiary
The Tertiary is a deprecated term for a geologic period 65 million to 2.6 million years ago. The Tertiary covered the time span between the superseded Secondary period and the Quaternary...
.