Pilosocereus
Pilosocereus leucocephalus
Pilosocereus is a genus of flowering plants of the cactus family ( Cactaceae ). The botanical name of the genus derives from the Latin word for pilosus, hairy 'as well as the related genus Cereus and means haired Cereus. He refers to the present in some species characteristic long hair.
Pilosocereus is widespread in Central and South America. Most species are native to Brazil. The shrubby or tree-like plants growing specialize in pollination by bats. Two of the approximately 40 species recognized today were already known to Linnaeus and have been described by the mid 18th century in his work Species Plantarum.
- 2.1 pollination
- 2.2 spread
- 4.1 Outer systematics
- 4.2 Internal systematics
- 6.1 Literature
- 6.2 Notes and references
Description
Vegetative characteristics
The species of the genus Pilosocereus grow shrubby or tree-like with erect, ascending to ajar shoots, which are strong to weak woody. You branch usually above the ground, reach a height of up to 10 meters and can form a non- articulated stem, diameter of 8 to 12 inches ( or more). Older plants have close to one another, parallel, upright branches forming a narrow crown. The branches tend to grow without interruption and are rarely - such as in Pilosocereus catingicola - divided. The smooth or rarely rough epidermis of shoots is green to gray or blue wax. The cellular tissue of cortex and medulla is usually very schleimhaltig.
On the shoots are 3 to 30 low, rounded ribs. The groove between the ribs may be straight or wavy. The rib apex is sometimes notched between the areoles. Only at a Brazilian species distinct warts can be seen. The person sitting on the ribs circular to elliptical areoles are only a few miles away and often confluent in Blühbereich. The areoles are tomentose, that is, They are covered with short, densely packed and interwoven hair. These soft hairs are usually white or yellow-brown to blackish and up to 8 millimeters long. At the flower-bearing areoles they reach a length of up to 5 centimeters. Seated on the areoles nectar glands are not visible.
From each areole spring 6 to 31 spines, which can not be distinguished in peripheral and central spines. The opaque to translucent, yellow to brown or black spines are smooth, needle-like, straight, rarely curved at its base. Frequently the thorns turn gray with age. They are usually from 10 to 15 millimeters in length, but can reach up to 40 mm length.
A special flower zone, ie the area of the shoots, in which the flowers are formed is not pronounced to strong. Occasionally, a lateral cephalium is formed, which is sometimes more or less sunk in the shoots.
Flowers
The tube- to bell-shaped flowers appear on the side of the shoots or below the shoot tips. They open in the evening twilight or at night. The flowers are 5 to 6 cm ( often 2.5 to 9 inches ) long and have diameters of 2 to 5 centimeters ( often up to 7 inches ) on. The smooth Perikarpell is bare and rarely occupied with few or inconspicuous leaf shed. The flower tube is straight or slightly curved and occupies at the top of half or one-third with leaf shed. The ganzrandigen or tiny denticulate 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 pale pink or reddish in color and 9 to 26 millimeters long and 7.5 millimeters wide.
It is a broad, upright or swollen nectar chamber available, which is more or less protected by the innermost stamens, which are bent to 25 to 60 mm long stylus out. The slightly warty 1.2 to 2.5 mm long anthers appear as a compact mass. The 8-12 carpels can protrude from the shell flower.
Fruit and seeds
Are the spherical or depressed globular, very rarely egg-shaped fruits, as with all cacti, false fruits. They are 20 to 45 mm long and have diameters of 30 to 50 millimeters. On them shall be liable a perennial, black expectant flowers rest. Her smooth, striped or shriveled fruit wall is colored red to purple or bluish green. The firm flesh is white, red, pink or magenta. The fruits burst always along the lateral, abaxialer, adaxialer or central slits.
The shell-shaped or hat -shaped (with Pilosocereus gounellei ), dark brown or black seeds are 1.2 to 2.5 millimeters long. With the exception of Pilosocereus gounellei the expression of the hilum - micropyle region is insignificant. The cross-section of the cells of the seed coat varies from convex to flat, and is tapered only at Pilosocereus aureispinus. Intercellular Dimple, a common feature of all cacti, with the exception of Pilosocereus densiareolatus pronounced. The folds of the cuticle can be thin, coarse or absent.
Genetics
The base chromosome number of the genus equivalent to that of all cactus.
Ecology
Pollination
The flowers of Pilosocereus are to pollination by bats adapted ( Chiropterophilie ). It is believed that two different trends of adapting to these pollinators exist. The first is a specialization of the flower-bearing areoles and in a reduction of flower length. It was observed mainly in felsbewohnenden species. An example is Pilosocereus floccosus. The second form of adaptation is connected with the specialization of the flowers to the pollination by flower bats that do not have to land on the flower to collect nectar. Here, the flower-bearing areoles are usually almost bare and the flowers are extended. This form has been observed especially in forest-dwelling species. Pilosocereus pentaedrophorus is an example of this adjustment.
Spread
The spread of the fruit and seeds is carried out in various ways. At her both wind, water and animals are involved. The juicy, sweet flesh attracts birds, insects (eg wasps large ), lizards and mammals that can spread the seeds contained in it over long distances. Some species appear by the nature of the seed coat on the spread by ants ( myrmecochory ) to be specialized. It was found locations of Pilosocereus aureispinus, who were on ant nests. From the unique in the tribe Cereeae seeds of Pilosocereus gounellei that swim very well, is believed to contribute to its spread the occasional flooding in the Caatinga.
Dissemination
The genus Pilosocereus is in Mexico, the Caribbean - including the Florida Keys - and in Colombia, Venezuela, Guyana, Suriname, Ecuador, Peru, Brazil and Paraguay, so in most parts of tropical South America, spread. The area with the greatest biodiversity is located in the central and northeastern part of the Brazilian state of Minas Gerais. Of the Brazil-based species 20 percent are known only from a single location.
System
Outer systematics
Pilosocereus is classified within the cactus family in the tribe Cereeae and is considered from a phylogenetic point of view as one of the most primitive genera within the tribe. It differs from the other genera of the tribe by the depressed spherical fruits that burst with irregular slots and contain a solid white or colored flesh.
Inside systematics
The first description was in 1957 by Ronald Stewart Byles and Gordon Douglas Rowley. As a type species of the genus Byles and Rowley laid the Mexico originated kind Pilocereus fixed leucocephalus.
There have been several attempts to define the genre Pilosocereus taxonomically further subdivide. Franz Buxbaum introduced in 1972 to a subgenus Lagenopis for his no longer recognized genus Coleocephalocereus containing the luetzelburgii today is ranked as Stephanocereus kind. Pierre Braun led the set up by Buxbaum subgenus 1988 formally transferred to the genus Pilosocereus. Daniela Zappi described in 1994 with Gounellea another subgenus, in which she had received the two Brazilian species Pilosocereus gounellei and Pilosocereus tuberculatus, and was mainly due to a delimitation of species with candelabra -like growth and branching at the tip of branches. After the redescription of Pilosocereus bohlei by Andreas Hofacker Pierre Braun and Eddie Esteves Pereira questioned the division into sub-genera in question.
Belong to the genus of the following types:
- Pilosocereus albisummus
- Pilosocereus alensis
- Pilosocereus arrabidae
- Pilosocereus aureispinus
- Pilosocereus aurisetus Pilosocereus aurisetus subsp. aurisetus
- Pilosocereus aurisetus subsp. aurilanatus
- Pilosocereus brasiliensis subsp. brasiliensis
- Pilosocereus brasiliensis subsp. ruschianus
- Pilosocereus catingicola subsp. catingicola
- Pilosocereus catingicola subsp. salvadorensis
- Pilosocereus floccosus subsp. floccosus
- Pilosocereus floccosus subsp. quadricostatus
- Pilosocereus fulvilanatus subsp. fulvilanatus
- Pilosocereus fulvilanatus subsp. rosae
- Pilosocereus fulvilanatus subsp. vanheekianus
- Pilosocereus gounellei subsp. gounellei
- Pilosocereus gounellei subsp. zehntneri
- Pilosocereus pachycladus subsp. pachycladus
- Pilosocereus pachycladus subsp. pernambucoensis
- Pilosocereus pentaedrophorus subsp. pentaedrophorus
- Pilosocereus pentaedrophorus subsp. robustus
Synonyms of the genus are Pilocereus K.Schum. and Pseudopilocereus Buxb.
Botanical history
The first known description of a Pilosocereus comes from Charles Plumier. During one of his trips to America he recorded in 1690 in Port -de- Paix on Haiti a plant that he Americanum arbor beginning of the 18th century in his Catalogus Plantarum as Opuntia excelsa, Cereiformis flore, albo -characterized. Joseph Pitton de Tournefort undertook this description in his three-volume seminal work Institutiones Rei Herbariae. Plumiers drawing was not published until more than fifty years later in John Burman work Americanarum Plantarum ( 1755-1760 ). Today, this kind is known under the name Pilosocereus polygonus. Among the by Carolus Linnaeus published Species Plantarum in cacti was with Cactus royenii another species of the genus.
When Charles Lemaire in 1839 his first description of the genus Pilocereus [ sic] published, he cared for more than one hundred -year-long taxonomic confusion, as he had the year before, published by Ludwig Georg Karl Pfeiffer description of the genus Cephalocereus overlooked and his new genus also with the type Cactus senilis (now Cephalocereus senilis ) described by Adrian Hardy Haworth had typed.
Karl Moritz Schumann tried the problem with a new description for Pilocereus and with the allocation of the new type species Pilocereus houlletii Lem. to get around. However, an invalid according to the International Code of Botanical Nomenclature homonym arose. Nathaniel Lord Britton and Joseph Nelson Rose introduced in 1920 in their book, The Cactaceae all previously described species of the genus Pilocereus simply in the genus Cephalocereus. 1937 Erich beat Werder man in front to keep the name Pilocereus as " nomen conservandum ". An application to the 1954 meeting in Paris, the International Botanical Congress failed, however, because of the ICBN apply pursuant to Article 18: "The name of a taxon must be changed if the type of the name is excluded. "
Ronald Stewart Byles and Gordon Douglas Rowley solved the problem by echoing the old name they published in 1957 the new name Pilosocereus and 58 species in the new genus you included in it a relative of the Werdermann 1933 published species. Buxbaum, who considered the creation of the genus Pilosocereus as unnecessary, in 1968 created the genus Pseudopilocereus, in which he recorded all Brazilian species described so far and a Caribbean Style ( Pilosocereus nobilis). Until the early 1980s many authors ( so Buining and Bredero, Diers and Esteves Pereira ) considers Buxbaum and published numerous species followed by the generic name Pseudopilocereus. Friedrich Ritter (1979 ) and Pierre Joseph Brown ( 1988), led many of the species described as Pseudopilocereus in the genus Pilosocereus.
Daniela Zappi, the Brazilian representative of the genus examined at the University of São Paulo between 1988 and 1992 as part of her doctoral thesis, accepted in their work 26 Brazilian species with 8 subspecies and 8 non-native species in Brazil. Since Zappis work of 1994, the new species were Pilosocereus azulensis (1997), Pilosocereus estevesii (1999), Pilosocereus occultiflorus (1999), Pilosocereus bohlei (2001), Pilosocereus goianus (2002), Pilosocereus mollispinus (2004), Pilosocereus pseudosuperfloccosus (2009) and Pilosocereus frewenii (2011) described.