Thelocactus
Encyclopedia
Cactus
A cactus is a member of the plant family Cactaceae. Their distinctive appearance is a result of adaptations to conserve water in dry and/or hot environments. In most species, the stem has evolved to become photosynthetic and succulent, while the leaves have evolved into spines...
family, Cactaceae. Members of the genus are native to the arid lands of Central and Northern Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
.
Description
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, are rather low and normally marked with raised, angular or hexagonal tubercles. These tubercles can sometimes be difficult to distinguish. Areole
Areole
Areoles are an important diagnostic feature of cacti, and identify them as a family distinct from other succulent plants. The areoles on cacti are clearly visible; they generally appear as small light- to dark-colored bumps, out of which grow clusters of spines...
s 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.
Distribution
Thelocactus species grow in the wild in central and North MexicoMexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
but also on the other (northern) side of the Rio Grande
Rio Grande
The Rio Grande is a river that flows from southwestern Colorado in the United States to the Gulf of Mexico. Along the way it forms part of the Mexico – United States border. Its length varies as its course changes...
, in Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
. Species can be distinguished by where they grow, whether in mountainous stony/rocky places or grassy territory with clay
Clay
Clay is a general term including many combinations of one or more clay minerals with traces of metal oxides and organic matter. Geologic clay deposits are mostly composed of phyllosilicate minerals containing variable amounts of water trapped in the mineral structure.- Formation :Clay minerals...
soil.
Cultivation
Thelocactus species are generally easy to cultivate, even if many species fail to flower until they are five years old. SoilSoil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...
s should be composed of equal proportions of sand
Sand
Sand is a naturally occurring granular material composed of finely divided rock and mineral particles.The composition of sand is highly variable, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal...
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 seed
Seed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...
s 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.
Synonymy
The following genera have been brought to synonymy with Thelocactus:- Hamatocactus BrittonNathaniel Lord BrittonNathaniel Lord Britton was an American botanist and taxonomist who founded the New York Botanical Garden in the Bronx, New York. Britton was born in New Dorp in Staten Island, New York...
& RoseJoseph Nelson RoseJoseph Nelson Rose was an American botanist. He was born in Union County, Indiana. His father died serving during the Civil War when Joseph Rose was a young boy. He later graduated from high school in Liberty, Indiana....
This genus contained 8 species and was known from the Southwest United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
and in northern Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
. The name Hamatocactus means "hooked cactus" in Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
.
- Thelomastus FricAlberto Vojtech FricAlberto Vojtěch Frič was a famous Czech botanist, ethnographer, writer and explorer. He undertook 8 voyages to America, discovered, described and catalogued many species of cactus....
(nom. inval.)
Selected species
- Thelocactus argenteus
- Thelocactus bicolor (GaleottiHenri Guillaume GaleottiHenri Guillaume Galeotti was a French-Belgian botanist and geologist of Italian parentage who was born in Paris. He specialized in the study of the family Cactaceae....
ex Pfeiff.Ludwig Karl Georg PfeifferLudwig Karl Georg Pfeiffer, also known as Louis Pfeiffer was a German physician, botanist and conchologist.-Biography:He received his education in Kassel, and became professor of pathology there in 1828...
) BrittonNathaniel Lord BrittonNathaniel Lord Britton was an American botanist and taxonomist who founded the New York Botanical Garden in the Bronx, New York. Britton was born in New Dorp in Staten Island, New York...
& RoseJoseph Nelson RoseJoseph Nelson Rose was an American botanist. He was born in Union County, Indiana. His father died serving during the Civil War when Joseph Rose was a young boy. He later graduated from high school in Liberty, Indiana....
– Glory of Texas - Thelocactus conothelos
- Thelocactus leucacanthus
- Thelocactus nidulans
- Thelocactus setispinus (Engelm.George EngelmannGeorge Engelmann, also known as Georg Engelmann, was a German-American botanist. He was instrumental in describing the flora of the west of North America, then very poorly-known; he was particularly active in the Rocky Mountains and northern Mexico.-Origins:George Engelmann was born in Frankfurt...
) E.F.Anderson – Fishhook Cactus, Miniature Barrel Cactus - Thelocactus tulensis
Formerly placed here
- Turbinicarpus beguinii (N.P.Taylor) Mosco & Zanov. (as T. beguinii N.P.Taylor)
- Turbinicarpus gielsdorfianusTurbinicarpus gielsdorfianusTurbinicarpus gielsdorfianus is a species of plant in the Cactaceae family. It is endemic to Mexico. Its natural habitat is hot deserts.-Source:...
(Werderm.) V.John & Ríha (as T. gielsdorfianus (Werderm.) Borg) - Turbinicarpus horripilusTurbinicarpus horripilusTurbinicarpus horripilus is a species of plant in the Cactaceae family. It is endemic to Mexico. Its natural habitat is hot deserts.-Source:* Anderson, E.F., Fitz Maurice, W.A. & Fitz Maurice, B. 2002. . Downloaded on 23 August 2007....
(Lem.) V.John & Ríha (as T. horripilus (Lem.) Kladiwa) - Turbinicarpus knuthianusTurbinicarpus knuthianusTurbinicarpus knuthianus is a species of plant in the Cactaceae family. It is endemic to Mexico. Its natural habitats are temperate forests and hot deserts.-Source:...
(Boed.) V.John & Ríha (as T. knuthianus (Boed.) Borg) - Turbinicarpus lophophoroidesTurbinicarpus lophophoroidesTurbinicarpus lophophoroides is a species of plant in the Cactaceae family. It is endemic to Mexico. Its natural habitats are subtropical or tropical dry lowland grassland and hot deserts. It is threatened by habitat loss.- Source :...
(Werderm.) Buxb. & Backeb. (as T. lophophoroides Werderm.) - Turbinicarpus mandragoraTurbinicarpus mandragoraTurbinicarpus mandragora is a species of plant in the Cactaceae family. It is endemic to Mexico. Its natural habitat is hot deserts.-Source:* Fitz Maurice, W.A., Fitz Maurice, B. & Hinton, G. 2002. . Downloaded on 23 August 2007....
(Fric ex A.Berger) A.D.Zimm. (as T. mandragora A.Berger) - Turbinicarpus pseudopectinatusTurbinicarpus pseudopectinatusTurbinicarpus pseudopectinatus is a species of plant in the Cactaceae family. It is endemic to Mexico. Its natural habitats are temperate forests and hot deserts...
(Backeb.) Glass & R.A.Foster (as T. pseudopectinatus (Backeb.) E.F.Anderson & Boke) - Turbinicarpus saueriTurbinicarpus saueriTurbinicarpus saueri is a species of plant in the Cactaceae family. It is endemic to Mexico. Its natural habitat is hot deserts.-Source:* Fitz Maurice, W.A., Fitz Maurice, B. & Hofer, A. 2002. . Downloaded on 23 August 2007....
(Boed.) V.John & Ríha (as T. saueri (Boed.) Borg) - Turbinicarpus subterraneusTurbinicarpus subterraneusTurbinicarpus subterraneus is a species of plant in the Cactaceae family. It is endemic to Mexico. Its natural habitat is hot deserts.-Source:...
(Backeb.) A.D.Zimm. (as T. subterraneus (Backeb.) Backeb. & F.M.Knuth) - Turbinicarpus viereckiiTurbinicarpus viereckiiTurbinicarpus viereckii is a species of plant in the Cactaceae family. It is endemic to Mexico. Its natural habitat is hot deserts.-Source:* Anderson, E.F., Fitz Maurice, W.A., Fitz Maurice, B. & Hofer, A. 2002. . Downloaded on 23 August 2007....
(Werderm.) V.John & Ríha (as T. viereckii (Werderm.) Bravo) - Turbinicarpus ysabelaeTurbinicarpus ysabelaeTurbinicarpus ysabelae is a species of plant in the Cactaceae family. It is endemic to Mexico. Its natural habitat is hot deserts.-Source:* Fitz Maurice, W.A. & Fitz Maurice, B. 2002. . Downloaded on 23 August 2007....
(Schlange) V.John & Ríha (as T. ysabelae Schlange)