Pilosocereus

From M&J Cactus Wiki
Pilosocereus
File:Pilosocereus leucocephalus.jpg
Kingdom Plantae
Family Cactaceae
Subfamily Cactoideae
Tribe Cereeae
SubTribe
Genus Pilosocereus
Species
Notes Taxonomy follows Joël Lodé (2015) with additional morphological and molecular insights from Zappi (1994), Machado et al. (2006), and Bàrcenas et al. (2011).

Etymology

The name means "hairy Cereus", referring to the abundant pilosity of the pseudocephalium characteristic of many species.

Description

Pilosocereus is a genus of columnar, shrubby to tree-like cacti, often forming candelabra-like structures and reaching up to 10 m in height.

  • Habit: Columnar, often strongly branched; stems with mucilage.
  • Epidermis: Smooth, grey-green to bluish, often glaucous.
  • Ribs: 3–30, straight, often with a transverse groove below the areoles.
  • Areoles: Felted; strongly woolly in reproductive zones, sometimes forming pseudocephalia.
  • Spines: Variable; usually straight, acicular, sometimes translucent.
  • Flowers: Nocturnal, tubular to campanulate, white to pink; self-sterile.
  • Pollination: Primarily chiropterophilous (bats), but also by moths, bees, hummingbirds and other birds.
  • Fruits: Globose to flattened, thick-walled; irregularly dehiscent; pulp white to pink or purple.
  • Seeds: Shiny, dark brown to black, striate, broadly ovate to spoon-shaped.

Habitat

Wide ecological amplitude:

  • dry forests, thorn scrub, tropical valleys and mountainous regions
  • rocky, sandy, limestone, sandstone, granitic and quartz substrates
  • caatinga and campo rupestre ecosystems in Brazil

Altitude range: sea level to approximately 1900 m.

Distribution

Very widely distributed:

  • Caribbean islands
  • Central America
  • South America (especially Brazil)
  • Mexico
  • southern United States (Florida)

Countries include: Brazil, Mexico, Colombia, Venezuela, Peru, Ecuador, Paraguay, USA, and many Caribbean nations.

Taxonomy

The genus has a complex taxonomic history.

  • Pilocereus (Lemaire, 1839) is illegitimate due to typification issues with Cephalocereus senilis
  • Pilosocereus was established by Byles & Rowley (1957) with P. leucocephalus as type species

Key insights:

  • Zappi (1994): major morphological revision of Brazilian taxa
  • Machado et al. (2006): suggested polyphyly among related genera
  • Bàrcenas et al. (2011): recovered a monophyletic Pilosocereus (limited sampling)

The genus is currently accepted, but further molecular work is needed.

Species

Following Joël Lodé (2015), including recognized subspecies.

Notes

  • One of the most widely distributed cactus genera.
  • High ecological adaptability across tropical and subtropical regions.
  • Pollination syndromes are diverse (bats, insects, birds).
  • Some subgeneric groups (e.g. Gounellea) may be taxonomically separated in the future.
  • Seed morphology and juvenile traits may help resolve taxonomic uncertainties.