cactusclassification – Page 8 – THE LAST CACTUS CLASSIFICATION

May 24, 2016May 24, 2016

REBUTIA

Autor: Schumann

• ETYMOLOGY
Genus honouring Pierre Rebut (1828-1898), French cactus nurseryman.
• DESCRIPTION
A genus of small size, low growing plants, solitary or forming compact clumps, globose depressed or shortly cylindrical. Areoles variable, rounded, ovate or elliptic. Spines tiny, usually fine, extremely variable in size, sometimes hairlike, mostly white.
Flowers diurnal, usually self-fertile, funnel-shaped, with pericarpel practically glabrous, yellow, orange, pink or red, pollinated by bees. Fruits rather small, globose, dry papery when ripe, disintegrating. Seeds numerous, ovate, black, shiny. Dispersal ensured by ants (myrmecochory).
• HABITAT
The genus Rebutia grows often in crevices or at feet of rocks, in the highlands of Bolivia and northern Argentina, from 1200 m up to 3600 m in altitude, where it withstands snow and sometimes severe frosts, but under a very low level of humidity.
• DISTRIBUTION
Argentina (Catamarca, Jujuy, Salta, Tucuman), Bolivia (Tarija).

Currently 5 likely species + one (or more?) subspecies, but according to Hunt et al. 2006, only 3 very variable species (R.fabrisii, R. minuscula and R. padcayensis):
– Rebutнa fabrisii* Rausch 1977 + subsp.?
– Rebutнa krainziana* Kessel ring 1948
– Rebutнa marsoneri* Werderm. 1937
– Rebutнa minuscula* K.Schum. 1895 (= R. senilis)
– Rebutнa minuscula subsp. wessneriana (Bewer.) Muruaga 2008
– Rebutнa padcayensis* Rausch 1970 (= R. margarethae)

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

May 24, 2016May 24, 2016

RAUHOCEREUS

Autor: Backeberg

• ETYMOLOGY
Genus honouring Prof. Werner Rauh (1913-2000), German botanist, explorer and director of the Botanical garden of the University of Heidelberg in Germany, specialist of the Peruvian flora (and Madagascar).
• DESCRIPTION
A genus of shrubby columnar plants, branching usually from the base, forming groups of erect bluish green stems, with 5-6 tuberculate ribs. Tubercles with very characteristic facets, areoles woolly. Radial spines short, sometimes pectinate, 2 centrals sturdier and longer.
Flowers nocturnal, self-sterile, bell-shaped to rotate, appearing near the apex of stems, with floral tube bearing small scales and frizzy brown hairs, white, pollinated by bats (Anoura caudifer, A. geoffroyi, Glossophaga soricina). Fruits egg-shaped, fleshy, raspberry red to violet purple, with longitudinal dehiscence from the base, pulp orange to scarlet, floral remains persistent. Seeds rather small, elongated, black, shiny, finely pitted and striate.
• HABITAT
The monotypic genus Rauhocereus grows endemically in northern Peru, from approximately 400 m up to 2500 m in altitude, often among a dense vegetation of dry forests and shrubs, in a loamy soil.
• DISTRIBUTION
Peru (Amazonas, Cajamarca, Lambayeque).

Currently 1 only recognised species, plus a doubtful subspecies:
– Rauhocereus riosaniensis* Backeberg 1958
– Rauhocereus riosaniensis subsp. jaenensis (Rauh) Ostolaza 1998

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

May 24, 2016May 24, 2016

RAPICACTUS

http://static.inaturalist.org/photos/420268/original.jpg?1444608177

Autor: Buxbaum & Oehme

• ETYMOLOGY
“Turnip Cactus”, referring to the shape of the root in this genus, a long taproot.
• DESCRIPTION
A genus of small plants, globose to elongated, constricted towards the base, usually solitary, with the apex woolly. Large taproot, often exceeding the volume of the plant above the soil, often hoisted on a very thin neck (R. subterraneus). Ribs absent, divided into tubercles. Areoles situated at the tip of tubercles, woolly, white, having dense, straight and sharp spines.
Flowers diurnal, self-sterile, appearing at the apex of stems, funnel-shaped, white to pink, pollinated by insects, mainly bees and flies. Fruits berry-like. Seeds striate, with hllum and micropyle disjoint.
• HABITAT
With its napiform root, the genus Rapicactus can live in extreme ecological niches, dry areas where little or no other cacti grow, mimetic, almost invisible, on soils or walls of calcareous rocks, sometimes on acid soils (R. beguinii), from approximately 1000 m up to 3200 m in altitude.
• DISTRIBUTION
Mexico (Coahuila, Nuevo Leon, San Luis Potosi, Tamaulipas, Zacatecas).

Currently 6 recognised species + one possible subspecies:
– Rapicactus beguinii* (N. P. Taylor) Luthy 2003
– Rapicactus beguinii subsp. hintoniorum (Hofer) Luthy 2003
– Rapicactus booleanus* (Hinton) Donati 2003
– Rapicactus mandragora* (Fric ex. Berger) Buxb & Oehme 1943
– Rapicactus pailanus (Halda & Panarotto) Donati 2003
– Rapicactus subterraneus* (Backbg.) Buxb & Oehme 1942
– Rapicactus zaragozae* (Glass & Forster) Donati 2003

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

May 24, 2016May 29, 2016

QUIABENTIA

Autor: Britton & Rose

• ETYMOLOGY
“Quiabento”, vernacular name given to plants of this genus in Brazil, and commonly used.
• DESCRIPTION
A genus of shrubby plants (Q. zehntneri) or treelike (Q. verticillata), with cylindrical succulent branches, densely branched, often verticillate. Leaves succulent, flattened, ovate to spatulate, persistent to seasonal. Areoles bearing glochids and numerous spines.
Flowers diurnal, solitary, self-sterile, sessile, appearing near or at the ends of branches, rotate, pericarpel with areoles bearing leaves, glochids and spines, pink or red, sometimes very pale to almost white, pollinated by insects. Fruits elongated, fleshy or dry. Seeds large, irregularly rounded and flattened, wrapped in a sclerotic aril. Dispersal of seeds ensured by – among others and only in some regions – the tapir (Tapirus terrestris).
• HABITAT
The genus Quiabentia grows in seasonally dry deciduous forests, scrubs, on usually sandy or clayey soils, but also on gravel, rocky limestone outcrops (Bambui formation), sometimes associated with Pereskia sacharosa-, in Brazil, it is found in the caatinga, on granitic or gneissic inselbergs, from sea level up to 2200 m in altitude.
• DISTRIBUTION
Argentina (Chaco, Formosa, Jujuy, Salta), Bolivia (Cochabamba, Chuqulsaca, Santa Cruz, Tarija), Brazil (Bahia, Minas Gerais), Paraguay (Alto Paraguay, Boqueron, Presidente Hayes).

Currently 2 recognised species:
– Quiabentia verticillata* (Vaupel) Borg 1937 (= Q. chacoensis)
– Quiabentia zehntneri* (Britton & Rose) Britton & Rose 1923

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

May 24, 2016May 24, 2016

PUNOTIA

Autor: D.R. Hunt

• ETYMOLOGY
Anagram of Opuntia, but at the same time referring to Puno, city of Peru near where the genus was found.
• DESCRIPTION
Monotypic genus of low growing plants forming wide compact cushions of several metres in diameter, with short, cylindrical, sometimes globose and tuberculate segmented stems, densely covered with hairs (trichomes). Leaves tiny, cylindrical, almost hidden by hairs, soon deciduous. Areoles with fine hairs, with scattered, sunken glochids, easily detached. A single, short spine (2-2.5cm), yellow.
Flowers diurnal, self-sterile, with hairy pericarpel, golden yellow, pollinated by hymenoptera. Fruits egg-shaped, thinwalled, containing some pulp, yellow to pale pink when ripe. Seeds large (up to 5 mm in diameter), pale yellow, having a funicular envelope densely covered with trichomes.
• HABITAT
The monotypic genus Punotia grows in the highlands of the Bolivian and Peruvian Andes, forming compact cushions, from 4100 up to 4700 m in altitude, in regions where climate change has evolved since the last ice age (10,000 years B.P.), to become 3500 years B.P., a steppe area with wetlands (Graf 1981). This genus likes constant soil moisture and the roots should never dry out during the growing season! It should be the same for Austrocylindropuntia fioccosa, since this taxon grows very often sympatric up to 4550 m together with Punotia lagopus.
• DISTRIBUTION
Peru (Puno), Bolivia (La Paz).

Currently only one recognised species:
– Punotia lagopus* (K.Schumann) D.R.Hunt 2011

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