Author: cactusclassification

Posted on

THRIXANTHOCEREUS

http://cactiguide.com/graphics/t_senilis_600.jpg
http://cactiguide.com/graphics/t_senilis_600.jpg

Autor: Backeberg

• ETYMOLOGY
≪Cereus with hairy flowers≫, because the calyx of the flowers has fine hairs.
• DESCRIPTION
A genus of cereiform plants, mostly solitary, rarely branching, if so, from the base, exceeding no more than 4 m high, having very early long setose hairs at the base, ribs finely tuberculate, bearing a slightly sunken cephalium when adult, (Espostoci species have a cephalium deeply sunken in a groove), with long hairs and bristles. Areoles woolly, spines usually finely aciculate.
Flowers nocturnal, self-sterile, appearing often in groups along and at the top of stems in the cephalium, white, pollinated by bats, but probably also by moths, also curiously purple in T. senilis, probably pollinated this time; by hummingbirds. Fruits hairy, with a plurilongitudinal dehiscence. Seeds variable, helmet-shaped such as in Frailea (T. blossfeldiorum), or small and black (T. senilis). Dispersal by ants (myrmecochory).
• HABITAT
The genus Thrixanthocereus is endemic to Peru and grows mainly in valleys of the rio Maranon, in mountain forests, dry or humid, surrounded by an abundant vegetation (7. blossfeldiorum), but also in a spiny and dry matorral and on steep slopes (T. senilis), always in extremely rocky soils, from 400 m up to 2670 m in altitude.
• DISTRIBUTION
Peru (Amazonas, Ancash, Cajamarca, La Libertad, Piura).

Currently 4 recognised species:
– Thrixanthocereus blossfeldiorum* (Werderm.) Backeb. 1937
– Thrixanthocereus cullmannianus F.Ritter 1961
– Thrixanthocereus longispinus F.Ritter 1961
– Thrixanthocereus senilis* F.Ritter 1961

References: "TAXONOMY of the CACTACEAE" -  ISBN 978-84-617-3692-8 (Vol. 2)

 

Posted on

THELOCACTUS

http://www.llifle.com/photos/Thelocactus_tulensis_var._buekii_10253_l.jpg
http://www.llifle.com/photos/Thelocactus_tulensis_var._buekii_10253_l.jpg

Autor: (K. Schumann) Britton & Rose

• ETYMOLOGY
“Cactus with nipples”, referring to the characteristic nipple-shaped tubercles of species included in this genus.
• DESCRIPTION
A genus of small plants, solitary or caespitose, globose with the apex depressed, or conical to cylindrical not exceeding 40 cm high and 20 cm in diameter. Ribs often indistinct, but tubercles usually well defined, rounded or conical. Areoles situated at the apex of tubercles, tubercles sometimes elongated and grooved; nectariferous glands present or absent. Spines usually straight, variable in size and colour, central spines longer and sturdier than the radiais.
Flowers diurnal, appearing at the apex of stems, funnel-shaped, with a scaly floral tube, white, yellow, pink to magenta, rarely orange to red, pollinated by insects. Fruits greenish to reddish, scaly, basally dehiscent when ripe, from a pore where seeds escape freely, floral remains persistent. Seeds black, pear-shaped, with a sunken basal hilum, testa cells tabular, convex or conical, smooth or warty. Dispersal myrmecophilous and probably also through hydrochory (pers. obs.).
• HABITAT
The genus Thelocactus has an extensive geographic range between the southern United States and northern Mexico, and grows on quite varied mineral substrates, alluvial soils, often among grasses, between rocks, on stony, sandy, siliceous soils, limestone (eg. T. buekii subsp. matudae) or gypsum (eg. T. rinconensis subsp. nidulans, among ferns and spikemosses), in the matorral (formation consisting of spiny thickets), also in mountains, in pine forests, as part
of a plant community consisting of Cactaceae, bromeliads and other succulents, between 50 m (T. bicolor subsp. schwarzii) and 2700 m in altitude.
• DISTRIBUTION
Mexico (Coahuila, Durango, Hidalgo, Nuevo Leon, Queretaro, San Luis Potosi, Tamaulipas, Zacatecas), USA (New Mexico, Texas).

Currently 11 recognised species (+ 14 subspecies) following Mosco & Zanovello (2000):
– Thelocactus bicolor* (Galeotti ex Pfeiff.) Britton & Rose 1922
– Thelocactus bicolor subsp. bolaensis (Runge) Doweld 1999
– Thelocactus bicolor subsp. flavidispinus (Backeberg) N.P. Taylor 1998
– Thelocactus bicolor subsp. heterochromus* (Weber) Mosco & Zanovello 2000
– Thelocactus bicolor subsp. schwarzii (Backeb.) N.P.Taylor 1998
– Thelocactus buekii (Klein) Britton & Rose 1923
– Thelocactus buekii subsp. matudae (Sanchez-Mej. & A.Lau) Mosco & Zanovello 2000
– Thelocactus conothelos* (Regel & Klein) Backeb. & F.M.Knuth 1935
– Thelocactus conothelos subsp. argenteus (Glass & Foster) Glass 1998
– Thelocactus conothelos subsp. aurantiacus (Glass & Foster) Glass 1998
– Thelocactus conothelos subsp. flavus (Mosco & Zanovello) Mosco & Zanovello 2000 (=T. panarottoanus)
– Thelocactus conothelos subsp. garciae (Glass) Mosco & Zanovello 2000
– Thelocactus hastifer* (Werderm. & Boedeker) F.M.Knuth 1935
– Thelocactus hexaedrophorus* (Lem.) Britton & Rose 1922
– Thelocactus hexaedrophorus ssp. Iloydii (Britt. & Rose ) N.P.Taylor 1998
– Thelocactus lausseri* Riha & Busek 1986
– Thelocactus leucacanthus* (Zucc. ex Pfeiff.) Britton & Rose 1923
– Thelocactus leucacanthus subsp. schmollii (Werderm.) Mosco & Zanovello 1999
– Thelocactus macdowellii* (Rebut ex Quehl) Glass 1969
– Thelocactus multicephalus Halda & Panarotto 1998
– Thelocactus rinconensis* (Poselg.) Britton & Rose 1923
– Thelocactus rinconensis subsp. freudenbergeri (Haas) Mosco & Zanovello 1999
– Thelocactus rinconensis subsp. hintonii* Luthy 1997
– Thelocactus rinconensis subsp. nidulans (Quehl) Glass 1998
– Thelocactus tulensis* (Poselg.) Britton & Rose 1923

References: "TAXONOMY of the CACTACEAE" -  ISBN 978-84-617-3692-8 (Vol. 2)

 

Posted on

TEPHROCACTUS

http://i65.photobucket.com/albums/h233/mcdigpc2/IMG_2395.jpg
http://i65.photobucket.com/albums/h233/mcdigpc2/IMG_2395.jpg

Autor: Lemaire

• ETYMOLOGY
“Ash Cactus”, referring to the characteristic ash grey colour of the epidermis of some species in this genus.
• DESCRIPTION
A genus of small bushy to shrubby plants, with dense terminal or subterminal branches, producing numerous globose or cylindrical segments which, in some species, appear stacked on top of each other. Roots sometimes tuberous. Leaves tiny, deciduous. Areoles with trichomes, glochids sunk in cavities, and spines sometimes absent.
Flowers diurnal, self-sterile, rotate, appearing at the apex of segments, white or pink, also yellow, orange or red, pollinated by specialized hymenoptera (Alloscirtetica lanosa). Fruits dry or juicy (T. nigrispinus), dehiscent when ripe. Seeds large, irregular, creamy-white to brown, piled up in fruits, embryo comma-shaped, perisperm prominent, light enough to be scattered by the wind, but the seeds of some species are dispersed in the excreta of animals which feed on the fruits (endozoochory) such as chinchillas (Chinchilla brevicaudata, C. chinchilla, the latter unfortunately extinct, Lagidium peruvianum) and guanacos (Llama guanicoe). This fact suggests that we should not blindly trust classification based on seeds, which also adopt a convergence of form.
• HABITAT
The genus Tephrocactus grows at the top of or on stony hillslopes, in plains, on sandy, rocky, sometimes schistose soils, in the puna among grasses, usually in full sun, from 250 up to 3800 m in altitude. Tephrocactus is extremely widespread and variable in its habitat.
• DISTRIBUTION
Argentina (Catamarca, Cordoba, Jujuy, La Rioja, Mendoza, Salta, San Juan, San Luis, Santiago del Estero, Tucuman), Bolivia (Potosi, Chuquisaca), Chile (Tarapaca).
Currently 10 recognised species + one subspecies:
– Tephrocactus alexanderi* (Britton & Rose) Backeb. 1953
– Tephrocactus aoracanthus* (Lem.) Lem. 1868
– Tephrocactus articulatus* (Pfeiff.) Backeb. 1953
– Tephrocactus bonnieae* (Ferguson & Kiesling) Stuppy 2001 (ex Puna bonnieae)
– Tephrocactus geometricus (A.Cast.) Backeb. 1935
– Tephrocactus molinensis* (Speg.) Backeb. 1953
– Tephrocactus nigrispinus* (K. Schumann) Backeb. 1935
– Tephrocactus nigrispinus subsp. atroglobosus (Backeb. ex Guiggi & Palacios) M.Lowry 2012
– Tephrocactus recurvatus* (Gilmer & H.P.Thomas) D.R.Hunt & Ritz 2011 (ex T. curvispinus Backeb. 1963, nom. invai., ex Cumulopuntia recurvata)
– Tephrocactus verschaffeitii* (F.A.C.Weber) D.R.Hunt & Ritz 2011 (ex Austrocyl. verschaffeitii)
– Tephrocactus weberi* (Speg.) Backeb. 1935

References: "TAXONOMY of the CACTACEAE" -  ISBN 978-84-617-3692-8 (Vol. 2)

 

Posted on

TACINGA

http://cactiguide.com/graphics/t_palmadora_600.jpg
http://cactiguide.com/graphics/t_palmadora_600.jpg

Autor: Britton & Rose

• ETYMOLOGY
Anagram of Catinga (or Caatinga), Northeastern region of Brazil where the species of this genus live. It is characterized by a semi-desert xerophytic vegetation consisting of spiny deciduous shrubs and cacti.
• DESCRIPTION
A genus of bushy or lianiform plants, erect, climbing or crawling, with stems segmented, cylindrical, or elongated and flattened, rounded or elliptic. Leaves extremely reduced, cylindrical, deciduous. Areoles black, producing glochids which loosen easily. Spines 1-6 aciculate, of variable size, sometimes absent or falling easily.
Flowers diurnal or nocturnal, self-sterile, borne near the stem tips, perianth segments strongly recurved in some species, erect stamens not sensitive (unlike Opuntia), pale yellow tinged with greenish, brownish or purplish, or deep orange to red, with a thick, hollow and scaly floral tube, areoles with glochids, pollinated by hummingbirds or insects during the day, nocturnal pollinators unknown. Fruits elongated, fleshy, green, whitish, brownish or reddish, deeply umbilicate, remains of dried perianth deciduous. Seeds large (up to 5 mm) whitish to brownish, usually few, globose to subglobose or pyriform (pear-shaped), slightly compressed laterally, with leathery aril; funicular envelope densely covered with trichomes.
• HABITAT
The genus Tacinga grows in the caatinga, spiny dry forest of the Brazilian northeast, also in Venezuela, on limestone or granite outcrops, on rocky soils, under trees among other cacti and succulents (Melocactus, Arrojadoa, Jatropha and caudiciform or geophytic plants), between 20 m (T. lilae) and 1550 m in altitude. Some species such as T. funalis grow with the help of tree branches, in a tangle of inextricable stems, on detrital soils.
• DISTRIBUTION
Brazil (Alagoas, Bahia, Minas Gerais, Paraiba, Pernambuco, Rio Grande do Norte, Sergipe), Venezuela (Sucre).

Currently 8 recognised species + one subspecies and one hybrid:
– Tacinga braunii Esteves 1989
– Tacinga funalis* Britton & Rose 1919
– Tacinga inamoena* (K.Schum.) W.Stuppy & N.P.Taylor 2001
– Tacinga lilae* (Trujillo & M.Ponce) Majure & R.Puente 2013
– Tacinga palmadora* (Britton & Rose) W.Stuppy & N.P.Taylor 2001
– Tacinga saxatilis* (F.Ritter) W.Stuppy & N.P.Taylor 2001
– Tacinga saxatilis subsp. estevesii (P.J.Braun) W.Stuppy & N.P.Taylor 2001
– Tacinga subcylindrica (M.Machado & N.P.Taylor) M.Machado & N.P.Taylor 2011
– Tacinga werneri (Eggli) W.Stuppy & N.P.Taylor 2001
– Tacinga x quipa (F.A.C.Weber) W.Stuppy & N.P.Taylor 2001

References: "TAXONOMY of the CACTACEAE" -  ISBN 978-84-617-3692-8 (Vol. 2)

 

Posted on

STROPHOCACTUS

https://c5.staticflickr.com/8/7235/7196029172_305b368047_b.jpg
https://c5.staticflickr.com/8/7235/7196029172_305b368047_b.jpg

Autor: Britton & Rose

• ETYMOLOGY
≪Wrapped cactus≫, referring to the way that plants of certain species in this genus (S. wittii, S. testudo) wrap themselves around trees.
• DESCRIPTION
A genus of epiphytic or epilithic plants, climbing or pendulous, polymorphic, one of them myrmecophilous (S. testudo), with angled or flattened, segmented stems, appressed against trunks, branches or rocks, with aerial roots. Areoles woolly, garnished with strong spines.
Flowers nocturnal, self-sterile, funnel-shaped, with a very long, scaly and hairy floral tube, with widely opened petals, pure white, strongly to unpleasantly fragrant, pollinated by Sphingideae (Barthlott et al. 1997). Fruits globose, spiny, yellow, greenish or red, pulp fragrant, retaining the remains of the dried perianth. Seeds oboval, light brown, smooth.
• HABITAT
The genus Strophocactus grows in hot and humid tropical zones, as an epiphytic, fixed by its roots to trees (Pachira aquatica) and mangroves (Rhizophora mangle), at water level, near rivers and streams, in easily flooded areas (S. wittii), or crawling on rocks (S. testudo), from sea level up to 1100 m in altitude.
• DISTRIBUTION
Belize, Brazil (Amazonas), Colombia (Guainia, Vaupes), Costa Rica (Guanacaste, Heredia, Limon), El Salvador, Guatemala (Alta Verapaz, Chiquimula, Huehuetenango, Izabal, Peten, Zacapa), Honduras (Atlantida, Cortes, Francisco Morazan), Mexico (Chiapas, Oaxaca, Quintana Roo, Tabasco, Veracruz, Yucatan), Nicaragua (Esteli), Panama, Peru (Loreto), Venezuela (Amazonas).

Currently 3 recognised species:
– Strophocactus chontalensis* R.Bauer 2003
– Strophocactus testudo* (Karw. ex Zucc.) R.Bauer 2003
– Strophocactus wittii (K. Schum.) Britton & Rose 1913

References: "TAXONOMY of the CACTACEAE" -  ISBN 978-84-617-3692-8 (Vol. 2)