''Neobuxbaumia macrocephala'' is a long-lived columnar

cactus A cactus (, or less commonly, cactus) is a member of the plant family Cactaceae, a family comprising about 127 genera with some 1750 known species of the order Caryophyllales. The word ''cactus'' derives, through Latin, from the Ancient Greek ...

Distribution

It is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the Tehuacán-Cuicatlán Valley in central

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

. Within this region the species may be found on calcareous soil in xerophytic shrublands and

tropical dry forest The tropical and subtropical dry broadleaf forest is a habitat type defined by the World Wide Fund for Nature and is located at tropical and subtropical latitudes. Though these forests occur in climates that are warm year-round, and may receive ...

at an altitude of 1700 m above sea level.

Description

It is a branched columnar cactus that reaches between 7 and 15 m in height. The number of branches in an adult plant may vary from one to 10. Plants bear a reddish cephalium at the tip of each branch from which purple-red

flowers A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechani ...

emerge between May and June, during the end of the dry season. The species is hermaphroditic and its flowers are mainly nocturnal, opening at sunset (1900 h) and closing in the morning (1000 h). The bats ''

Choeronycteris mexicana The Mexican long-tongued bat (''Choeronycteris mexicana'') is a species of bat in the family Phyllostomidae. It is monotypic, the only species within the genus ''Choeronycteris''. The species is found in El Salvador, Guatemala, Honduras, Mexico, ...

'' Tschudi, '' Leptonycteris curasoae'' Miller, and ''

Leptonycteris nivalis The greater long-nosed bat or Mexican long-nosed bat (''Leptonycteris nivalis'') is a species of bat in the family Phyllostomidae. It is found in Mexico and the United States. It chiefly consumes pollen and nectar, particularly from agave plan ...

'' (Saussure) are the main pollinators that promote seed production. Fruits ripen from June to August and are consumed by bats and bird species that probably act as seed dispersers. ''Neobuxbaumia macrocephala'' occurs at densities between 130 and 200 individuals/ha. Seed germination and seedling establishment occurs mostly beneath the canopies of several species of trees and shrubs, such as '' Pseudosmodingium multifolium'', ''

Lippia graveolens ''Lippia graveolens'', a species of flowering plant in the verbena or vervain family, Verbenaceae, is native to the southwestern United States (Texas and southern New Mexico), Mexico, and Central America as far south as Nicaragua. Common names i ...

'', '' Gochnatia hypoleuca'', and ''

Aeschynomene compacta ''Aeschynomene'' is a genus of flowering plants in the family Fabaceae, and was recently assigned to the informal monophyletic ''Dalbergia'' clade of the Dalbergieae. They are known commonly as jointvetches. These legumes are most common in warm ...

''. First reproduction occurs when plants are around 2 m tall.

Ecology

The microbiota associated to this species include methylotrophic bacteria, see

Methylotroph Methylotrophs are a diverse group of microorganisms that can use reduced one-carbon compounds, such as methanol or methane, as the carbon source for their growth; and multi-carbon compounds that contain no carbon-carbon bonds, such as dimethyl et ...

, both in its stem surface and inside the plant. Their function might be related to the growth promotion of ''N. macrocephala'', but it has not been demonstrated yet.

Conservation status

CITES Appendix II - Trade controlled to avoid use incompatible with species survival.

Synonyms

''Carnegiea macrocephala'' (F.A.C. Weber ex K. Schum.) P.V. Heath Calyx 2(3): 109. 1992. (Calyx)
''Cereus macrocephalus'' (F.A.C. Weber ex K. Schum.) A. Berger Annual Report of the Missouri Botanical Garden 16: 62. 1905. (Rep. (Annual) Missouri Bot. Gard.)
''Cereus melocactus'' (F.A.C. Weber ex K. Schum.) A. Berger Annual Report of the Missouri Botanical Garden 16: 62. 1905. (Rep. (Annual) Missouri Bot. Gard.)

References

Bibliography

Godínez-Alvarez, H., and A. Valiente-Banuet. 2004. Demography of the columnar cactus Neobuxbaumia macrocephala: a comparative approach using population projection matrices. Plant Ecology 174: 109-118. Esparza-Olguín, L., T. Valverde, and E. Vilchis-Anaya. 2002. Demographic analysis of a rare columnar cactus (Neobuxbaumia macrocephala) in the Tehuacán Valley, México. Biological Conservation 103: 349-359.

External links

Info at tropicos.org
{{Taxonbar, from=Q1977451 macrocephala Endemic flora of Mexico Tehuacán Valley matorral