''Cephalocereus'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of slow-growing, columnar-shaped, blue-green

cacti A cactus (: cacti, cactuses, or less commonly, cactus) is a member of the plant family Cactaceae (), a family of the order Caryophyllales comprising about 127 genera with some 1,750 known species. The word ''cactus'' derives, through Latin, ...

. The genus is native to

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

Description

These cacti show a columnar and upright growth habit, and may be branched or unbranched reaching heights of 10 to 12 meters. The light green shoots, which turn gray with age, have a diameter of up to 40 centimeters and are almost completely covered by dense thorns near the top. On the 12 to 30 (or more) vertical ribs are closely spaced dimorphic areoles. The up to 5 central spines are yellowish to gray and up to 4 centimeters long. The numerous, bristly or hair-like radial spines usually enclose the shoot tightly. The flowers are medium-sized, tubular to bell-shaped, borne in a woolly structure called cephalium which can appear apically or laterally and open at night. The flower cup and the flower tube are covered with small scales. The fruits are ovoid with small scales, and woolly. The smooth, pear-shaped seeds are black.

Taxonomy

The genus ''Cephalocereus'' was established in 1838 by

Ludwig Karl Georg Pfeiffer Ludwig Karl Georg Pfeiffer, also known as Louis Pfeiffer (4 July 1805 – 2 October 1877), was a German physician, botany, botanist and conchology, conchologist. Early life, education and medical career Pfeiffer was born in Cassel, the eldest so ...

Species

Plants of the World Online Plants of the World Online (POWO) is an online taxonomic database published by the Royal Botanic Gardens, Kew. History Following the Convention on Biological Diversity, the Royal Botanic Gardens in Kew launched Plants of the World Online i ...

accepted the following species:

Distribution and habitat

This genus of cacti is native to central and southern

. Its habitat is

desert scrub Deserts and xeric shrublands are a biome defined by the World Wide Fund for Nature. Deserts and xeric (Ancient Greek 'dry') shrublands form the largest terrestrial biome, covering 19% of Earth's land surface area. Ecoregions in this habitat ...

in the Central Mexican matorral and

Southern Pacific dry forests The Southern Pacific dry forests is a tropical dry broadleaf forest ecoregion in southern Mexico. Geography The Southern Pacific dry forests occupy the coastal lowlands and foothills along the Pacific coast of Southern Mexico. The Balsas River ...

References

External links

*
photos on www.AIAPS.org
*
photos on www.cactiguide.com

GBIF entry
{{Taxonbar, from=Q133859 Cactoideae genera Cacti of Mexico Endemic flora of Mexico