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Thelocactus | |
---|---|
Thelocactus rinconensis | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Order: | Caryophyllales |
Family: | Cactaceae |
Subfamily: | Cactoideae |
Tribe: | Cacteae |
Genus: | Thelocactus (K.Schum.) Britton & Rose [1] |
Type species | |
Thelocactus hexaedrophorus | |
Species | |
See text | |
Synonyms | |
Thelocactus is a genus of flowering plants in the cactus family Cactaceae. Members of the genus are native to the arid lands of Central and Northern Mexico.
Thelocactus species are globe-shaped, short and cylindrical. They are small cacti, although there are one or two species which, while only about 15 cm high, can be 25 cm in diameter; for example, T. nidulans. Thelocactus species are generally solitary, but some varieties will cluster in groups.
The ribs on Thelocactus species are very clearly marked and are sometimes twisted in a spiral. There can be from 8 to 20 ribs, which are rather low and normally marked with raised, angular or hexagonal tubercles. These tubercles can sometimes be difficult to distinguish. Areoles sit in a furrow directly above where the spines grow and there can be up to twenty radial/radiating spines. They are often needle-like, spread out and can be from 1.3 – 1.5 cm long. The central spines are mostly coarser, number up to six, stand vertically out from the plant and can be 2.5 – 7.5 cm long. Colours of all of the spines vary and include white, gray, golden-yellow and red-brown.
Flowers grow from the new areoles at the very top of the plant. They are funnel-shaped, have a diameter of 2.5 – 7.5 cm and their colours vary from white to shades of yellow, red or purple. They are diurnal. Fruits are small, globe-shaped and plain. They are dehiscent through the large basal pore, green to brownish purple [to magenta], spherical to short cylindrical, 5 - 18 x 6 – 17 mm, not juicy, drying immediately after ripening, scaly, spineless, hairless and with floral remnant persistent.
Thelocactus species grow in the wild in central and North Mexico and in the US in Texas. In Mexico, the species are generally concentrated along and to the west of the Sierra Madre Oriental beginning with T. hastifer in Querétaro State, about 150 km NNW of Mexico City. One subspecies (T. bicolor ssp. flavidispinus) grows on the other (northern) side of the Rio Grande, well distributed in the Big Bend area of Texas. Other occurrences of T. bicolor in Texas have been reported but cited verification is sketchy although it would be odd if they did not occur there. Some species are distributed over a wide area of many Mexican states (T. bicolor and its subspecies and T. hexaedrophorus) with T. bicolor and its current (2013) botanically accepted subspecies bolaensis, flavidispinus, heterochromus and schwarzii having the widest distribution. In contrast, one species, T. lausseri, only occurs in one known remote locality in central Coahuila state. Species are distributed in mountainous stony/rocky places or grassy territory with clay soil.
Thelocactus species are generally easy to cultivate, even if many species fail to flower until they are five years old. Soils should be composed of equal proportions of sand and humus. Water normally from Spring to Autumn. In Winter, keep most species at a minimum temperature of 8 °C. They can survive at lower temperatures but the roots then must be kept dry. The dark brown or black seeds can be relatively large for the size of cactus and they germinate readily.
Reproduction is nearly always from seed, since the plant rarely produces plantlets. The seed should be put in a sand and compost mixture, kept moist, maintained at a temperature of 21 °C and placed in a shady position.
Thelocactus bicolor has gained the Royal Horticultural Society's Award of Garden Merit. [2]
The following genera have been brought to synonymy with Thelocactus:
This genus contained 8 species and was known from the Southwest United States and in northern Mexico. The name Hamatocactus means "hooked cactus" in Latin.
Species recognized by International Cactaceae Systematics Group. (Anderson E. F., 2001)
Image | Scientific name | Sub-species | Distribution |
---|---|---|---|
Thelocactus bicolor (Galeotti ex Pfeiffer) Britton & Rose |
| northern Chihuahuan Desert of the USA (Texas) and Mexico. | |
Thelocactus conothelos (Regel & Klein) Backeb. & F.M.Knuth |
| Mexico (Chihuahua, Coahuila de Zaragoza, Durango, Nuevo León, Tamaulipas) | |
Thelocactus garciae Glass & M.Mendoza | Mexico (Tamaulipas ) | ||
Thelocactus hastifer (Werdermann & Boedeker) F.M.Knuth | Mexico (Querétaro de Arteaga) | ||
Thelocactus heterochrontus (F.A.C.Weber) Oosten | Mexico(Chihuahua, Durango, Zacatecas ) | ||
Thelocactus hexaedrophorus (Lemaire) Britton & Rose |
| Mexico (Nuevo León, San Luis Potosí, Tamaulipas, Zacatecas) | |
Thelocactus lausseri Riha & Busek | Mexico ( Coahuila de Zaragoza ) | ||
Thelocactus leucacanthus (Zuccarini) Britton & Rose |
| Mexico (Hidalgo, Querétaro de Arteaga) | |
Thelocactus macdowellii (Rebut ex Quehl) Glass | Mexico (Coahuila de Zaragoza, Nuevo León) | ||
Thelocactus rinconensis (Poselger) Britton & Rose |
| Mexico (Coahuila de Zaragoza, Nuevo León) | |
Thelocactus setispinus (Engelmann) E.F.Anderson | (syn. Hamatocactus setispinus) | Mexico (Coahuila de Zaragoza, Nuevo León, Tamaulipas), USA (Texas) | |
Thelocactus tulensis (Poselger) Britton & Rose |
| Mexico(Nuevo León, San Luis Potosí, Tamaulipas ) | |
Echinocactus is a genus of cacti in the subfamily Cactoideae. The generic name derives from the Ancient Greek ἐχῖνος (echînos), meaning "spiny," and cactus. It and Ferocactus are the two genera of barrel cactus. Members of the genus usually have heavy spination and relatively small flowers. The fruits are copiously woolly, and this is one major distinction between Echinocactus and Ferocactus. Propagation is by seed.
In 1984, the International Organization for Succulent Plant Study set up a working party, now called the International Cactaceae Systematics Group, to produce a consensus classification of the cactus family, down to the level of genus. Their classification has been used as the basis for systems published since the mid-1990s. Treatments in the 21st century have generally divided the family into around 125–130 genera and 1,400–1,500 species, which are then arranged in a number of tribes and subfamilies. However, subsequent molecular phylogenetic studies have shown that a very high proportion of the higher taxa are not monophyletic, i.e. they do not contain all of the descendants of a common ancestor. As of August 2023, the internal classification of the family Cactaceae remained uncertain and subject to change. A classification incorporating many of the insights from the molecular studies was produced by Nyffeler and Eggli in 2010.
Neolloydia is a formerly recognized genus of cacti. The genus was first erected by Britton and Rose in 1922. Edward F. Anderson regarded Neolloydia as being poorly defined, with the result that species that had at times been included in Neolloydia were afterwards placed in multiple genera, including Coryphantha, Echinomastus, Escobaria, Mammillaria, Sclerocactus, Thelocactus and Turbinicarpus. In his 2001 book, Anderson firmly placed only one species in the genus, Neolloydia conoidea, with another, Neolloydia matehualensis, being regarded as only a variant of N. conoidea. As of December 2022, Plants of the World Online treated Neolloydia conoidea as a synonym of Cochemiea conoidea, and Neolloydia as a synonym of Cochemiea.
Turbinicarpus is a genus of very small to medium-sized cacti, which inhabit the north-eastern regions of Mexico, in particular the states of San Luis Potosí, Guanajuato, Nuevo León, Querétaro, Hidalgo, Coahuila, Tamaulipas and Zacatecas.
Pilosocereus is a genus of cactus native to the Neotropics. Tree cactus is a common name for Pilosocereus species. The genera Caerulocereus and Pseudopilocereus are synonyms of this genus.
Morangaya is a monotypic genus of ribbed, usually small to medium-sized, cylindrical shaped cacti, that is native to north western Mexico. The only species is Morangaya pensilis. It is found in the mountains and rocky hills.
Hatiora is a small genus of epiphytic cacti which belongs to the tribe Rhipsalideae within the subfamily Cactoideae of the Cactaceae. Recent taxonomic studies have led to the three species formerly placed in subgenus Rhipsalidopsis being removed from the genus, including the well known and widely cultivated ornamental plants known as Easter cactus or Whitsun cactus.
Weingartia is a genus in the family Cactaceae, with species native to Bolivia and Argentina. Molecular phylogenetic evidence suggests that it may be distinct from Rebutia. It is treated as a synonym of that genus by Plants of the World Online as of September 2023, but recognized as an alternative generic name in the third edition of the CITES Cactaceae Checklist. It may also be treated as Rebutia subg. Weingartia.
Cacteae is a tribe of plants of the family Cactaceae found mainly in North America especially Mexico. As of August 2018, the internal classification of the family Cactaceae remained uncertain and subject to change. A classification incorporating many of the insights from the molecular studies was produced by Nyffeler and Eggli in 2010.
Kadenicarpus horripilus is a species of plant in the family Cactaceae.
Rapicactus mandragora, synonym Turbinicarpus mandragora, is a species of plant in the family Cactaceae.
Kadenicarpus pseudomacrochele, synonym Turbinicarpus pseudomacrochele, is a species of plant in the family Cactaceae.
Turbinicarpus pseudopectinatus is a species of plant in the family Cactaceae.
Turbinicarpus saueri is a species of plant in the family Cactaceae.
Turbinicarpus schmiedickeanus is a species of plant in the family Cactaceae.
Rapicactus subterraneus, synonym Turbinicarpus subterraneus, is a species of plant in the family Cactaceae. It is endemic to Mexico. Its natural habitat is hot deserts.
Mammillaria elongata, the gold lace cactus or ladyfinger cactus, is a species of flowering plant in the family Cactaceae, native to central Mexico. Growing to 15 cm (6 in) tall by 30 cm (12 in) wide, it consists of densely packed clusters of elongated oval stems, covered in harmless yellow or brown spines, and in spring producing white or yellow flowers. It is among the most common and most variable of its genus in nature, and is a popular subject for cultivation. It has gained the Royal Horticultural Society's Award of Garden Merit.
Thelocactus nidulans is a cactus in the genus Thelocactus of the family Cactaceae.
Thelocactus bicolor, the glory of Texas, is a species of flowering plant in the cactus family, widely distributed in the northern Chihuahuan Desert of the USA (Texas) and Mexico. Plants are usually solitary, but may form clumps. Growing to 50 cm (20 in) tall, it is a perennial with spiny, ribbed, succulent stems. Large daisy-like flowers, up to 8 cm (3.1 in) in diameter, are borne in summer. The petals are purplish-pink, fading to white. The inner petal tips form a circle of red surrounding a prominent yellow boss.
Pelecyphora zilziana is a species of flowering plant in the family Cactaceae, native to Mexico.
Media related to Thelocactus at Wikimedia Commons