Pilosocereus

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Pilosocereus
Pilosocereus leucocephalus

Pilosocereus leucocephalus

Systematics
Nuclear eudicotyledons
Order : Clove-like (Caryophyllales)
Family : Cactus family (Cactaceae)
Subfamily : Cactoideae
Tribe : Cereeae
Genre : Pilosocereus
Scientific name
Pilosocereus
Byles & GDRowley

Pilosocereus is a genus of plants fromthe cactus family (Cactaceae). The botanical name of the genus is derived from the Latin word pilosus for 'hairy' and the related genus Cereus and meanshairy Cereus . He refers to the characteristic long hairs found in some species.

Pilosocereus is common in Central and South America. Most of the species are native to Brazil . The shrubby or tree-like plants are specialized in pollination by bats . Two of the approximately 40 species recognized today were already known to Carl von Linné and were described by him in his work Species Plantarum in the mid-18th century .

description

Vegetative characteristics

The species of the genus Pilosocereus grow shrubby or tree-like with upright, ascending to ajar shoots that are strong to weakly woody. They usually branch above the ground, reach a stature height of up to 10 meters, and can develop a non-articulated trunk that is 8 to 12 centimeters (or more) in diameter. Older plants have closely spaced, parallel, upright branches that form a narrow crown. The branches usually grow without interruption and are only rarely structured - as in the case of Pilosocereus catingicola , for example . The smooth or rarely rough epidermis of the shoots is green to gray or wax blue. The cell tissue of the cortex and marrow is usually very mucous .

There are 3 to 30 low, rounded ribs on the shoots . The furrow between the ribs can be straight or undulating. The apex of the ribs is sometimes notched between the areoles . Only one Brazilian species can clearly see warts . The circular to elliptical areoles sitting on the ribs are only a little apart and often even converge in the flowering area. The areoles are tomentose, i.e. that is, they are covered with short, tightly packed and interwoven hair. These soft hairs are usually white or yellow-brown to blackish and up to 8 millimeters long. On the flower-bearing areoles they reach a length of up to 5 centimeters. Nectar glands located on the areoles are not visible.

From each areole 6 to 31 spines arise , which cannot be differentiated into marginal and central spines. The opaque to translucent, yellow to brown or black thorns are smooth, needle-shaped, straight and rarely curved at their base. The thorns often turn gray with age. They are usually between 10 and 15 millimeters long, but can reach up to 40 millimeters in length.

A special flower zone, i.e. the area of ​​the shoots in which the flowers are formed, is not or strongly pronounced. Occasionally a lateral cephalium is formed, which is sometimes more or less sunk into the shoots.

blossoms

Flower of Pilosocereus leucocephalus
Pilosocereus polygonus with fruits
Fruit of Pilosocereus polygonus

The tubular to bell-shaped flowers appear on the side of the shoots or below the shoot tips. They open at dusk or at night. The flowers are 5 to 6 centimeters (rarely 2.5 to 9 centimeters) long and have a diameter of 2 to 5 centimeters (rarely up to 7 centimeters). The smooth pericarpel is bare and rarely covered with a few or inconspicuous leaf scales. The flower tube is straight or slightly curved and half or one third of the upper end is covered with leaf scales. The entire or tiny serrated outer petals are greenish or rarely dark purple, pink or reddish. The inner petals are thinner than the outer and entire. They are white or rarely light pink or reddish in color and 9 to 26 millimeters long and 7.5 millimeters wide.

There is a wide, upright or swollen nectar chamber , which is more or less protected by the innermost stamens , which are bent towards the 25 to 60 millimeter long stylus . The somewhat warty, 1.2 to 2.5 millimeter long anthers appear like a compact mass. The 8 to 12 carpels can protrude from the flower envelope .

Fruits and seeds

The spherical or depressed spherical, very rarely egg-shaped fruits are, as with all cacti, false fruits . They are 20 to 45 millimeters long and have a diameter of 30 to 50 millimeters. A persistent, black-turning remnant of flowers adheres to them. Their smooth, striped or wrinkled pericarp is colored red to purple or bluish green. The firm flesh is white, red, pink or magenta in color. The fruits always burst along lateral, abaxial , adaxial or central slits.

The shell-shaped or cap-shaped (in Pilosocereus gounellei ), dark brown or black seeds are 1.2 to 2.5 millimeters long. With the exception of gounellei Pilosocereus the expression of is hilum - Mikropyle -area insignificant. The cross-section of the cells of the seed coat varies from convex to flat and is only conical in Pilosocereus aureispinus . Intercellular dimples, a common feature of all cacti, are clearly pronounced with the exception of Pilosocereus densiareolatus . The folds of the cuticle can be thin, rough, or absent.

genetics

The base chromosome number of the genus corresponds to that of all cactus plants.

ecology

pollination

The flowers of Pilosocereus are adapted to pollination by bats ( chiropterophilia ). It is believed that there are two different tendencies to adapt to these pollinators. The first consists of a specialization of the flowering areoles and a reduction in the length of the flowers. It was mainly observed in rock-dwelling species. One example is Pilosocereus floccosus . The second form of adaptation is associated with the flower's specialization in pollination by flowering bats , which do not need to land on the flower to collect nectar. Here the flower-bearing areoles are mostly almost bare and the flowers are elongated. This form was mainly observed in forest-dwelling species. Pilosocereus pentaedrophorus is an example of this adaptation.

Spread

The fruits and seeds spread in a variety of ways. Wind, water and animals are all involved in it. The juicy, sweet pulp attracts birds, insects (such as large wasps), lizards, and mammals, which can spread the seeds it contains over great distances. Some species seem to specialize in the spread of ants ( myrmecochory ) due to the nature of the seed coat . Locations of Pilosocereus aureispinus were found that were on ant nests. The seeds of Pilosocereus gounellei , which are unique in the tribe of Cereeae and swim very well, are believed to have contributed to their spread due to the occasional flooding in the caatinga .

distribution

Distribution area of ​​the genus Pilosocereus

The genus Pilosocereus is distributed in Mexico , the Caribbean - including the Florida Keys - as well as in Colombia , Venezuela , Guyana , Suriname , Ecuador , Peru , Brazil and Paraguay , i.e. in most of tropical South America . The area with the greatest biodiversity is located in the central and northeastern part of the Brazilian state of Minas Gerais . Of the species native to Brazil, 20 percent are only known from a single location .

Systematics

External system

Pilosocereus is classified within the cactus family in the tribe Cereeae and from a phylogenetic point of view is considered one of the most original genera within the tribe. It differs from the other genera of the tribe by the depressed spherical fruits, which burst open with irregular slits and contain a firm white or colored pulp.

Internal system

It was first described in 1957 by Ronald Stewart Byles and Gordon Douglas Rowley . Byles and Rowley specified the type Pilocereus leucocephalus , native to Mexico, as the type species of the genus .

There have been several attempts to further subdivide the genus Pilosocereus taxonomically. In 1972, Franz Buxbaum created a subgenus Lagenopis for his now no longer recognized genus Coleocephalocereus , which contained the species now classified as Stephanocereus luetzelburgii . In 1988, Pierre Braun formally converted the subgenus established by Buxbaum into the genus Pilosocereus . In 1994 Daniela Zappi described Gounellea, another subgenus, into which she included the two Brazilian species Pilosocereus gounellei and Pilosocereus tuberculatus , and which was essentially based on a delimitation of the species with candelabra-like growth and branches branching at the tip. After the new description of Pilosocereus bohlei by Andreas Hofacker, Pierre Braun and Eddie Esteves Pereira questioned the division into subgenera.

The genus includes the following species:

Synonyms of the genus are Pilocereus K.Schum. and Pseudopilocereus Buxb.

Botanical history

Pilosocereus polygonus around 1690 drawn by Charles Plumier in Port-de-Paix in Haiti

The demonstrably first description of a Pilosocereus comes from Charles Plumier . During one of his trips to America around 1690 in Port-de-Paix , Haiti , he drew a plant that he characterized in his Catalogus Plantarum Americanum at the beginning of the 18th century as Opuntia arbor, excelsa, Cereiformis, flore albo . Joseph Pitton de Tournefort adopted this description in his three-volume seminal work Institutiones Rei Herbariae . However, Plumier's drawing was not published until over fifty years later in Johannes Burman 's Plantarum Americanarum (1755–1760). Today this species is known under the name Pilosocereus polygonus . Among the cacti published by Carl von Linné in Species Plantarum was another species of the genus, Cactus royenii .

When Charles Lemaire wrote his first description of the genus Pilocereus [ sic! ] published, it caused taxonomic confusion that lasted over a hundred years because he had overlooked the description of the genus Cephalocereus published a year earlier by Ludwig Georg Karl Pfeiffer and his new genus also with the species Cactus senilis described by Adrian Hardy Haworth (today Cephalocereus senile ) typed had.

Karl Moritz Schumann tried the problem with a new description for Pilocereus and with the assignment of the new type species Pilocereus houlletii Lem. to bypass. However, this resulted in a homonym that is invalid according to the International Code of Botanical Nomenclature . Nathaniel Lord Britton and Joseph Nelson Rose put all previously described species of the genus Pilocereus in their work The Cactaceae in the genus Cephalocereus . In 1937 Erich Werdermann suggested that the name Pilocereus be kept as a " nomen conservandum ". A corresponding application at the International Botanical Congress , which met in Paris in 1954 , failed, however, because according to Article 18 of the ICBN : "The name of a taxon must be changed if the type of name is excluded."

Ronald Stewart Byles and Gordon Douglas Rowley solved the problem by publishing the new name Pilosocereus in 1957 following the old name and including 58 species in the new genus. They also included the species published by Werdermann in 1933. Buxbaum, who considered the creation of the genus Pilosocereus unnecessary, created the genus Pseudopilocereus in 1968 , in which he included all the Brazilian species described up to that point and a Caribbean species ( Pilosocereus nobilis ). By the early 1980s, many authors (such as Buining and Bredero, Diers and Esteves Pereira) followed Buxbaum's view and published numerous species under the generic name Pseudopilocereus . Friedrich Ritter (1979) and Pierre Josef Braun (1988) transferred many of the species described as Pseudopilocereus to the genus Pilosocereus .

Daniela Zappi, who examined the Brazilian representatives of the genus between 1988 and 1992 as part of her doctoral thesis at the University of São Paulo , accepted 26 Brazilian species with 8 subspecies as well as 8 non-Brazilian species in her work. Since Zappi's work in 1994, the new species Pilosocereus azulensis (1997), Pilosocereus estevesii (1999), Pilosocereus occultiflorus (1999), Pilosocereus bohlei (2001), Pilosocereus goianus (2002), Pilosocereus mollispinus (2004), Pilosocereus pseudosupus (2009) and Pilosocereus frewenii (2011). In the course of molecular genetic studies, various species, initially referred to as synonymy, were recognized again.

proof

literature

  • Edward F. Anderson : The Great Cactus Lexicon . Ulmer , Stuttgart 2005, ISBN 978-3-8001-4573-7 , p. 534-546 (Original title: The cactus family . Translated by Urs Eggli, with a foreword by Wilhelm Barthlott and an article by Roger Brown on cactus cultivation and care).
  • Curt Backeberg : The Cactaceae . Handbook of cactus science. 2nd Edition. tape IV . G. Fischer , Stuttgart / New York, NY 1984, ISBN 3-437-30383-X , p. 2387-2468 .
  • PJ Braun, E. Esteves Pereira: On the taxonomy of Pilosocereus Byles & Rowley (Cactaceae) . In: Cacti and other succulents . Volume 53, No. 9, Deutsche Kakteen-Gesellschaft, Pforzheim 2002, pp. 239-244.
  • Bruce D. Parfitt, Arthur C. Gibson: Pilosocereus . In: Flora of North America . Volume 4, online
  • Daniela C. Zappi: Pilosocereus (Cactaceae): The Genus in Brazil . Balogh Scientific Books, Sherborne 1994, ISBN 0-9517234-5-6 .

Individual evidence

  1. ^ A b Daniela C. Zappi: Pilosocereus (Cactaceae): The Genus in Brazil . Pp. 21-22
  2. ^ Daniela C. Zappi: Pilosocereus (Cactaceae): The Genus in Brazil . P. 27
  3. ^ Daniela C. Zappi: Pilosocereus (Cactaceae): The Genus in Brazil . P. 28
  4. ^ Daniela C. Zappi: Pilosocereus (Cactaceae): The Genus in Brazil . P. 23
  5. ↑ a b R. S. Byles, GD Rowley: Pilosocereus Byl. & Rowl. nom. gen. nov. (Cactaceae) . In: Cactus and Succulent Journal of Great Britain . Volume 19, Number 3, London 1957, pp. 66-67, p. 69.
  6. ^ PJ Braun, E. Esteves Pereira: On the taxonomy of Pilosocereus Byles & Rowley (Cactaceae) .
  7. ^ Edward F. Anderson: The great cactus lexicon . Eugen Ulmer KG, Stuttgart 2005, ISBN 3-8001-4573-1 , p. 534-546 .
  8. ↑ Godoy, M. Ortiz de: Diversidade e estrutura genética de Pilosocereus jauruensis: uma cactácea restrita aos enclaves de vegetação xérica no entorno do bioma Pantanal. - Diss., Universidade Federal de São Carlos, 2014.
  9. ^ Daniela Zappi, Nigel Taylor: A new species of Pilosocereus subgenus Gounellea, P. frewenii. from SE Brazil . In: Bradleya . Volume 29, 2011, pp. 131-136.
  10. ↑ Pierre J. Braun, Eddie Esteves Pereira, Andreas Hofacker: Pilosocereus hermii (Cactaceae) - a new type of cactus from northwestern Minas Gerais, Brazil In: Cacti and other succulents . Volume 58, Number 7, 2007, pp. 183-188.
  11. ↑ Pierre J. Braun, Esteves, E. & Esteves, R .: Pilosocereus jauruensis subsp. cincinnopetalus (Cactaceae, a new clan from mid-west Brazil. In: Cacti and other succulents . Volume 72 (3): 73-77.2020
  12. ↑ Godoy, M. Ortiz de: Diversidade e estrutura genética de Pilosocereus jauruensis: uma cactácea restrita aos enclaves de vegetação xérica no entorno do bioma Pantanal. - Diss., Universidade Federal de São Carlos, 2014.
  13. ↑ Calvente, A. & al. : Phylogenetic analyzes of Pilosocereus (Cactaceae) inferred from plastid and nuclear sequences. - Botanical Journal of the Linnean Society, Vol. 183 (1): 25-38. 2016
  14. ↑ Pierre J. Braun, Eddie Esteves Pereira: Pilosocereus pseudosuperfloccosus - a new cactus family from West Bahia, Brazil . In: Cacti and other succulents . Volume 60, Number 7, 2009, pp. 183-190.
  15. ↑ Calvente, A. & al. : Phylogenetic analyzes of Pilosocereus (Cactaceae) inferred from plastid and nuclear sequences. - Botanical Journal of the Linnean Society, Vol. 183 (1): 25-38. 2016
  16. ↑ Lavor Rolim, P .: Filogenia molecular, biogeografia e aspectos evolutivos de Pilosocereus (Cactaceae). Diss., Universidade Federal do Rio Grande do Norte Natal 2017.
  17. ↑ Pierre J. Braun: Pilosocereus rosae - again recognized as a species . In: Cacti and other succulents . Volume 70 (2): 41-42 2019
  18. ↑ Pierre J. Braun: Pilosocereus zahrae (Cactaceae) - a new species from Bahia, Brazil. In: Cacti and other succulents . Volume 70 (5): 145-150.2019
  19. ^ R. Mottram: Charles Plumier, the King's botanist: his life and work. With a facsimile of the original cactus plates and text from Botanicon Americanum (1689-1697) . In: Bradleya . Volume 20, 2002, p. 90.
  20. ^ Charles Plumier: Catalogus Plantarum Americanum . S. 6. In: Nova Plantarum Americanarum Genera . 1703-1704, online .
  21. ^ Joseph Pitton de Tournefort: Institutiones Rei Herbariae . Paris 1700, Volume 1, p. 240, online .
  22. ↑ Carl von Linné: Species Plantarum . Volume 1, pp. 467, 1753, online .
  23. ↑ Cactearum Genera Nova Speciesque Novae et Omnium in Horto Monvilliano. Paris 1839, p. 6.
  24. ↑ Dr. Pfeiffer: About Lemaire's description of some new cacti . In: General garden newspaper . Volume 6, number 18, 1838, p. 142, (online) .
  25. ^ Philosophical Magazine and Journal . Volume 63, 1824, p. 41, online .
  26. ↑ Cactus science . 1937, p. 130.
  27. ↑ F. Ritter: Cacti in South America. Results of my 20 years of field research . Volume 1, Spangenberg 1979, pp. 60-84.
  28. ^ PJ Braun: On the taxonomy of Brazilian Cereeae (Cactaceae) . In: Bradleya . Volume 6, 1988, pp. 85-99.
  29. ^ Curt Backeberg: Die Cactaceae: Handbuch der Kakteenkunde . 2nd Edition. Volume IV, pp. 2387-2388
  30. ^ Daniela C. Zappi: Pilosocereus (Cactaceae): The Genus in Brazil . Pp. 9-10.
  31. ^ Daniela C. Zappi: Pilosocereus (Cactaceae): The Genus in Brazil . Pp. 7-8.
  32. ↑ Godoy, M. Ortiz de: Diversidade e estrutura genética de Pilosocereus jauruensis: uma cactácea restrita aos enclaves de vegetação xérica no entorno do bioma Pantanal. - Diss., Universidade Federal de São Carlos, 2014.
  33. ↑ Lavor Rolim, P .: Filogenia molecular, biogeografia e aspectos evolutivos de Pilosocereus (Cactaceae). Diss., Universidade Federal do Rio Grande do Norte Natal 2017.
  34. ↑ Calvente, A. & al. : Phylogenetic analyzes of Pilosocereus (Cactaceae) inferred from plastid and nuclear sequences. - Botanical Journal of the Linnean Society, Vol. 183 (1): 25-38. 2016

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This version was added to the list of articles worth reading on February 18, 2010 .