• ETYMOLOGY
“Small Opuntia” making reference to the tiny size, the main feature of the genus. • DESCRIPTION
A genus of small low growing plants, strongly branched and forming clumps, with tuberous roots. Stems cylindrical, ellipsoid to clavate (with more or less prominent tubercles), usually erect, deciduous in the dry season. Areoles rounded having some grey wool, bearing tiny spines resembling glochids, and divergent spines somewhat flattened, the longest usually turned downward.
Flowers diurnal, quite large, bell-shaped, appearing at the tip of stems, pink to purple, pollinated by insects. Fruits obconical, at first smooth and juicy, becoming dry. Seeds large, discoid, size and thickness variable according to species, whitish. Dispersal unknown. • HABITAT
The genus Micropuntia grows in deserts, on rocky acid soils, among grasses, from 1200 m up to approximately 1900 m in altitude. It is also found on plains, sand dunes in dry river beds (M. pulchella), while other taxa grow on low sloping hills, among thick bushes. • DISTRIBUTION
USA (N. Arizona, California, Nevada, Utah).
• ETYMOLOGY
≪Candle with small flowers≫, referring to the usually tiny flowers of the species in this genus. • DESCRIPTION
A genus of solitary plants or sometimes with branched stems from the base, erect to decumbent, not woody, presenting a hypertrophic growth of spines on the basal areoles, but woody and lacking hypertrophic growth rate of spines on the basal areoles in the subgenus Austrocephalocereus. Ribs narrow, densely spiny, with close-set areoles. Pseudocephalium superficial to somewhat sunken (sunken in Austrocephalocereus). Flowers diurnal-nocturnal self-sterile, rather small, produced in a lateral pseudocephalium (an area modified on a
side of the stem where the areole develops additional bristles), tubular and numerous), often bi-coloured, with outer tepals pink or red and inner tepals yellow or white to creamy-white, with a foetid smell in M. purpureus, pollinated by bats (Aona & al. 2006 in Emerson 2007), the other species are pollinated by hummingbirds (Chlorostilbon aureiventris, C. lucidus, Phaethornis pretrei, P. squalidus, Eupetomena macroura), bees (Trigona spinipes) or
butterflies (Phoebis philea, Vettius sp.). Fruits small, turbinate, red when ripe, pulpy, floral remains persistent (Austrocephalocereus) or eventually falling (Micranthocereus). Seeds blackish-brown, smooth in Micranthocereus, with a striped and tuberculate cuticle in
Austrocephalocereus. Dispersal ensured by birds and bats. • HABITAT
The genus Micranthocereus is endemic to Brazil, and grows in the ≪campo rupestre≫, (mountainous subtropical savanna), among bushes and shrubs, on quartzic, rocky soils or between rocks, between 375 m and 1685 m in altitude (M. purpureus), together with other cacti (eg. Discocactus). • DISTRIBUTION
Brazil (Bahia, Minas Gerais).
Currently 8 recognised species (A = Austrocephalocereus) + with one (or more) subspecies:
– Micranthocereus (A.) albicephalus* (Burning & Brederoo) F.Ritter 1979
– Micranthocereus auriazureus Burning & Brederoo 197
– Micranthocereus flaviflorus* Burning & Brederoo 1974 (= M. densiflorus)
– Micranthocereus flaviflorus subsp. alvinii (M.Machado & Hofacker) J.Lode 2014
– Micranthocereus hofackerianus (P.J.Braun & Esteves) M.Machado 2006 (ex Arrojadoa)
– Micranthocereus polyanthus (Werderm.) Backeb. 1942
– Micranthocereus [A.) purpureus (Gurke) F.Ritter 1968
– Micranthocereus streckeri Van Heek & Van Criekinge 1986
– Micranthocereus (A.) violaciflorus Burning 1969
• ETYMOLOGY
≪Melon cactus≫, referring to the globular shape characteristic of most species within the genus. • DESCRIPTION
A genus of solitary plants (however being able to make clusters close to the cephalium if the apex has been damaged, or if the base of the cephalium is attacked by mealybugs), globose, elongated to cylindrical, with the apex depressed when juvenile. Ribs variable in number (8-27), well defined, not tuberculate. Areoles of variable size. Spines variable in size and number, radiais and centrals little or no differentiation, curved, sometimes slightly hooked, “centrals” generally more robust. Young stage (non reproductive): during this phase, species are globose, smaller than the adults and do not bear the reproductive attribute which is the cephalium. The cephalium is a modified portion of the stem bearing wool and bristles densely grouped, whose function is reproduction. Reproductive stage: adult plants develop a cephalium at the apex, which becomes in some species, cylindrical and very high (up to 1 m).
Flowers diurnal, self-fertile, mostly very small, tubular, naked, immersed in the cephalium, pink, more or less carmine red, or purple, pollinated by hummingbirds (Adelomyia melanogenys, Amazilia saucerrottei, A. tzacatl, Chlorostilbon aureoventris, C. canivetti caribaeus, C. lucidus, C. stenura, Chrysolampis mosquitus, Phaethornis pretrei, Eupetomena macroura) and also by insects, especially ants (Formicinae, Myrmicinae, Polichodrinae and Ponerinae), bees and butterflies (on M. glaucescens and M. paucispinus, Colaco et al. 2006 and Lambert et al. 2006, in Emerson 2007). Fruits naked, elongated, often davate, juicy, containing mucilage, appearing in the cephalium, floral remains persistent, white, pink, magenta red or pinkish. Seeds rather small, often numerous (+ 400), globose to egg-shaped, striate, warty, black. Dispersal of seeds insured through myrmecochory = ants (Ectatomma edentatum, cromyrmex laticeps nigrosetosus, Solenopsis substituta, Dorymyrmex thoracicus), ornithochory = birds, and saurochory = lizards, (Cnemidophorus ocellifer, Microlophus spp., Tropidurus cocorobensis, T. torquatus). • HABITAT
The genus Melocactus grows from South America up to Mexico and in the Caribbean islands, usually in warm and wet or relatively dry tropical regions, on crystalline (gneiss or granite) rocky outcrops, in crevices, sandy, clayey or siliceous areas, on serpentines, altered sandy conglomerates, soils of volcanic origin, andesites, also ferruginous soils, quartz gravels, in mountainsides among rocks, on rocky hillslopes, as well in full sun as in the shade of shrubs, in light woodlands, savannas, deserts, in valleys, sometimes close to the ocean, on dunes of pure quartz sand, on beaches, receiving sea spray, from sea level (M. intortus) up to 2160 m in altitude (M. bellavistensis subsp. onychacanthus), together with other cacti and succulents, as well as caudiciform plants and bromeliads. • DISTRIBUTION
The Antilles (Aruba, Bonaire, Curacao, Grenada, St Vincent), Bahamas, Brazil (Alagoas, Bahia, Ceara, Espirito Santo, Minas Gerais, Paraiba, Pernambuco, Piaui, Rio de Janeiro, Rio Grande do Norte, Roraima, Sergipe), Colombia (Boyaca, Cauca, Cundinamarca, Guajira, Huila, Magdalena, Santander, Tolima, Valle, Vichada), Costa Rica (Guanacaste), Cuba (Camaguey, Guantanamo, Holguin, Matanzas, Santa Clara, Santiago of Cuba), Ecuador (Loja), French Antilles
(Guadeloupe, La Desirade, Les Saintes, Marie-Galante, Martinique, Saint Barthelemy, Saint Martin), Guatemala (Baja Verapaz, Chiquimula, El Progreso, Quiche, Zacapa), Guyana, French Guyana, Honduras (Comayagua), Haiti, Jamaica, Mexico (Chiapas, Colima, Jalisco, Michoacan, Oaxaca, Veracruz), Nicaragua, Panama (Capira), Peru (Amazonas, Ancash, Arequipa, Cajamarca, La Libertad, Lambayeque, Lima, Piura, Tumbes), Puerto Rico, Dominican Republic (Pedernales),
Surinam (Nickerie, Saramacca), Trinidad and Tobago, Venezuela (Amazonas, Anzoategui, Apure, Aragua, Bolivar, Carabobo, D.F., Falcon, Guarico, Lara, Isla Margarita, Merida, Nueva Esparta, Sucre, Tachira, Trujillo, Zulia), Virgin Islands (Antigua).
• ETYMOLOGY
Genus native to Matucana, a town near Lima, Peru, where the genus was first discovered. • DESCRIPTION
A genus of low growing plants, solitary or caespitose, branching usually from the base, sometimes forming cushions. Stems globose, elongated to shortly cylindrical, with ribs very variable, low, more or less tuberculate; areoles bearing hairs and spines. Spines extremely variable according to species, numerous to few, often covering the epidermis of the plant, or simply absent.
Flowers diurnal, self-sterile, appearing near the apex, funnel-shaped with a more or less long floral tube with or without hairs, rarely actinomorphic (M. aureiflora, M. oreodoxa) or zygomorphic, intense red, orange, pink or yellow, pollinated by hummingbirds (Patagona gigas, Phaetornis spp.), but equally by bees. Fruits semi-globose to elongated, slightly fleshy, hollow, longitudinally dehiscent, floral remains persistent. Seeds variable, ovate either hood-shaped or helmet-shaped, blackish-brown, more or less shiny, ruminated or not, with a wide basal hilum, sometimes covered with the remains of the mucilage. Dispersion of seeds through myrmecochory and hydrochory. • HABITAT
The genus Matucana has extremely variable species, and grows endemically in the high valleys of the Andes in the North of Peru, mostly in full sun, in bare canyons, on cliffs, rocky hills, sometimes vertical slopes, often together with bromeliads, among grasses, mosses and lichens, and on rocky soils, from 280 m (M. paucicostata) up to 4200 m in altitude (M. comacephala). • DISTRIBUTION
Peru (Amazonas, Ancash, Arequipa, Ayacucho, Cajamarca, Huancavelica, Huanuco, Ica, Junin, La Libertad, Lima, Piura).
• ETYMOLOGY
Genus honouring the North American botanist William Taylor Marshall (1886-1957), co-founder of the association “Cactus and Succulent Society of America” in 1929, and director of the Phoenix Desert Botanical Garden in Arizona, USA, since 1946 until his death. • DESCRIPTION
A genus of vigorous treelike plants, erect columnar, branching from the base, typically without a defined trunk, stems dark green, shiny, more or less covered with wax forming a V shape with every new growth. 6-10 thick ribs, rounded, areoles rather small, felted with brown or grey wool. Radial spines short and aciculate (4-6 of 1 cm max.); 1-3 central spines a little longer.
Flowers nocturnal, self-sterile, funnel-shaped, tuberculate and scaly, appearing towards the upper part of stems, with greenish to purple outer tepals, inner tepals pinkish white to intense pink, generating huge quantities of nectar, pollinated by bats (Glossophaga leptocyneris). Large fruits like an egg when ripe, dry, with persistent spines, dehiscing like a five petalled flower, with white or red pulp, dispersal ornithophilous (Aimophila ruficauda, Amazilia rutila, Amazona albifrons, Arati riga canicularis, Calocitta formosa, Campylorhynchus rufinucha, Crotophaga sulci rostris, Dives dives, Heliomaster constantii, Icterus gularis, I. pustulatus, Melanerpes aurifrons, Mimus gilvus, Passerina versicolor, Quiscalus mexicanus, Zenaida asiatica). Seeds large, black, smooth and shiny. • HABITAT
The genus Marshallocereus grows in Central America, in semi arid areas, in the shade, in volcanic mountains covered with more or less dry deciduous tropical forests, sometimes at the edge of rivers, or not far from the Pacific Ocean, on rocks, together with other cacti, especially epiphytic, as well as bromeliads and orchids, from sea level up to 50 m in altitude, possibly more, but without more precise data. The average annual rainfall is about 680 mm. Both taxa are used by the local populations to make quickset hedges. • DISTRIBUTION
Costa Rica (Guanacaste, Puntarenas), El Salvador (Cuscatlan, Sonsonate, San Miguel, La Union), Guatemala (Baja Verapaz, Chuiquimula, El Progreso, Huehuetenango, Jutiapa, Quiche, Zacapa), Honduras (Yoro), Mexico (Chiapas), Nicaragua (Leon, Madriz), Panama.
Currently 1 recognised species + a doubtful subspecies:
– Marshallocereus aragonii* (F.A.C.Weber) Backeberg 1951
– Marshallocereus aragonii subsp. eichlamii* (Britton & Rose) Guiggi 2012
