Isolatocereus

Isolatocereus is a monotypic genus of flowering plant in the family Cactaceae. The only species is Isolatocereus dumortieri that is found in Mexico.^[2]

Isolatocereus
Conservation status
Least Concern  (IUCN 3.1)[1]
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Order:	Caryophyllales
Family:	Cactaceae
Subfamily:	Cactoideae
Tribe:	Echinocereeae
Genus:	Isolatocereus Backeb. 1942
Species:	I. dumortieri
Binomial name
Isolatocereus dumortieri (Scheidw.) Buxb. 1999
Synonyms
Cereus dumortieri Scheidw. 1837 Rathbunia dumortieri (Scheidw.) P.V.Heath 1992 Stenocereus dumortieri (Scheidw.) Buxb. 1961 Lemaireocereus dumortieri Britton & Rose 1909

Description

Isolatocereus dumortieri is a large, tree-like, and candelabra-shaped cactus, grows to heights of 5–15 meters, with a trunk exceeding 1-1.5 meter in length and about 35 cm in width. It is blue-green, covered with grayish wax. Branches erect, parallel to each other, all almost the same length, curved at the base, with the apex attenuated, up to 10 meters long and 5–15 cm in diameter. The cactus has 5–8 bluntly triangular ribs up to 2 cm high, and its areoles are dark. It features 1–4 yellowish-white central spines up to 5 cm long and 6–9 shorter reddish-brown wool and some short, bristly radial spines that darken over time, reaching 1 cm in length.

The scentless tubular flowers grow near the shoot tips and bloom multiple times, sometimes forming small crowns. They are mostly self-incompatible. They open at night and remain open until midday, appearing pale green to white, tubular to funnel-shaped, and 2.5–3.5 cm long. The edible fruits are subglobose to ellipsoid, remain green for some time, then turn orange to red, and measure 2.5–3.5 cm in length. They are covered in small red scales and contain black seeds approximately 1.5 mm in size.Fruits have red pulp, 3 to 4 cm long and 2 to 3.5 cm wide, covered with short podaries arranged in 4 series, with areoles provided with a reduced deltoid basal scab and short emerging felt, with very short spines, dehiscent at its apical part, giving off a pleasant aroma similar to that of jasmine, very juicy, fleshy and sweet when ripe^{[3] [4]}

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  Top of plant
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  Stem
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  Adult plant
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  Flowers

Distribution

Isolatocereus dumortieri is native to several Mexican states, including Aguascalientes, Guanajuato, Guerrero, Hidalgo, Jalisco, México, Michoacán, Morelos, Oaxaca, Puebla, Querétaro, San Luis Potosí, Veracruz, and Zacatecas at elevations between 1100 and 2200 meters.^[5] Plants are found in deciduous forest, grasslands growing on slopes or rocky cliffs growing along with Cephalocereus senilis. The flowers are pollinated animals that feed on the nectar including hummingbirds such as Amazilia violiceps, Cynanthus sordidus, and Cynanthus latirostris; bat such as Leptonycteris yerbabuenae, Leptonycteris nivalis, Glossophaga soricina, Choeronycteris mexicana, Sturnira lilium parvidens, and Dermanura tolteca; and bees. The seeds are dispersed by bats and Bassariscus astutus which eats the fruits.^[6]

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  Habitat in east Guamúchil, Guanajuato
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  Plant growing in habitat in Tequisquiapan, Querétaro
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  Plant growing in Querétaro, Querétaro
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  Plant growing in habitat near Río Venados, Hidalgo

Taxonomy

First described as Cereus dumortieri by Michael Joseph François Scheidweiler in 1837, the genus name "Isolatocereus" derives from the Italian word isolato (isolated). The species name honors Belgian botanist Barthélemy Charles Joseph Dumortier.^[7] It is also known by the common names "Candelabro," "Órgano," and "Pitayo." Curt Backeberg established the genus Isolatocereus in 1942, placing this species within it.^[8] Isolatocereus was split from Stenocereus into a separate genus (not all authorities had agreed with this as of 2008).^[9]