ACANTHOCEREUSAutor: (Engelmann ex Berger) Britton & Rose

“Spiny wax candle” referring to the spiny nature of the genus.
A genus of shrubby plants with branched stems, bent or climbing, forming impenetrable thickets. Stems are three or four angled (sometimes five), segmented or not, often with wavy ribs. They are mostly dimorphic (instead of monomorphic, young and mature plants are identical in Peniocereus). Short, strongly aciculate spines.
Flowers nocturnal, usually self-sterile, funnel-shaped, white, fragrant, with a long floral tube, robust and erect, pollinated by bats (Leptonycteris curasoae) and Sphingidae (Manduca rustica). Fruits fleshy, scaly and spiny, variable in shape, colour and spines, edible. Large seeds, papillose, shiny, elongated and striate, black or brown. Seed dispersal provided by bats and in some regions, by tapirs (Tapirus terrestris and T. bairdii).
The genus Acanthocereus grows in dry tropical forest, among shrubs, also in rocky or sandy areas, cliffs, near the coast, near mangrove (Costa Rica), and is able to form large populations, from sea level up to 1200 m in altitude. A.tetragonus is considered an invasive plant in New Caledonia and in Hawai, where sometimes it forms impenetrable thickets.
Caribbean islands, Belize, Colombia, Costa Rica (Guanacaste, Heredia, Limón), Cuba, El Salvador, Guatemala (Baja Verapaz, Chiquimula, El Progreso, Escuintla, Guatemala, Huehuetenango, Jutiapa, Petén, Santa Rosa, Zacapa), Honduras, Mexico (Campeche, Chiapas, Chihuahua, Colima, Guerrero, Jalisco, Michoacán, Nuevo León, Oaxaca, San Luis Potosí, Sinaloa, Veracruz, Yucatán), Nicaragua, Panama, USA (Florida), Venezuela.

Currently 18 species are recognised in this work (in brackets, taxa included before within
Peniocereus (P.), subgenus Pseudoacanthocereus, and transferred within Acanthocereus):
– Acanthocereus baxaniensis (Karw. ex Pfeiffer) Borg 1937
– Acanthocereus (P.) castellae* (Sánchez-Mej.) J.Lodé 2013
– Acanthocereus chiapensis* Bravo 1972
– Acanthocereus colombianus Britton & Rose 1920
– Acanthocereus (P.) cuixmalensis* (Sánchez-Mej.) J.Lodé 2013
– Acanthocereus (P.) fosterianus* (Cutak) J.Lodé 2013 (= P. nizandensis)
– Acanthocereus (P.) hirschtianus* (K.Schum.) J.Lodé 2013 (= P. guatemalensis)
– Acanthocereus horridus* Britton & Rose 1920
– Acanthocereus (P.) macdougallii* (Cutak) J.Lodé 2013
– Acanthocereus (P.) maculatus* Weing. ex Bravo 1933
– Acanthocereus (P.) marnierianus* (Backeb.) J.Lodé 2013
– Acanthocereus (P.) oaxacensis* (Britton & Rose) J.Lodé 2013
– Acanthocereus occidentalis* Britton & Rose 1920
– Acanthocereus pitajaya (Jacq.) Dugand ex Croizat 1943
– Acanthocereus (P.) rosei* (J.G.Ortega) J.Lodé 2013
– Acanthocereus subinermis Britton & Rose 1920
– Acanthocereus (P.) tepalcatepecanus* (Sánchez-Mej.) J.Lodé 2013
– Acanthocereus tetragonus* (L.) Hummelinck 1938

References: “TAXONOMY of the CACTACEAE” – ISBN 978-84-617-3723-9 (Vol. 1)




Autor: Backeberg

“Spiny head”, because the genus is completely covered with spines.
A genus of small solitary plants, more or less spherical to elongated, the apex depressed, many low ribs (30-60), divided into spiralled small tubercles. Many spines (25-60), small, but rather stiff and dense, white or yellow.
Flowers diurnal, rather small, appearing in the apex, more or less funnel-shaped to campanulate, with a short tube, self-fertile, greenish, yellowish-green, yellow, orange-coloured or red flame, usually pollinated by insects. Fruits spherical, abundantly setose, usually drying on the plant without opening, floral remains persistent. Seeds rather small, elongated, strongly warty, black. Strophiole absent.
The genus Acanthocephala grows in southern Brazil, from low altitudes up to 1500 m, among grasses, in the cracks of rocky terraces or hilly slopes, in the crevices of rocks, mostly among moss.
Brazil (Rio Grande do Sul).

Currently 2 recognised species:
Acanthocephala graessneri (K.Schum.) Guiggi 2012
Acanthocephala haselbergii* (Haage ex Rümpler) Guiggi 2012

References: “TAXONOMY of the CACTACEAE” – ISBN 978-84-617-3723-9 (Vol. 1)



acanthocalycium-minutum-428Autor: Backeberg & Knuth

“Spiny calyx”, referring to the main morphological characteristic of the genus.
A genus of usually single-stemmed plants, globose to lightly elongated, with the apex depressed. Ribs acute, more or less tuberculate, spines usually straight, aciculate to subulate.
Flowers diurnal, subapical (main difference with Echinopsis sensu lato), funnel-shaped to campanulate, white, pink or red, with floral tube formed by thorny scales (hence its name), pollinated by bees or sphingideae, more rarely by hummingbirds. Fruits hard, spherical, with persistent scales, with a vertical dehiscence. Seeds brownish to black, papillose, with the hilum depressed, scattered by rainwater (hydrochory).

The genus Acanthocalycium grows in northwest Argentina, at an altitude between 300 m and 3300 m, on sloping, arid, rocky ground, among grasses, bushes, in the shade of shrubs or in full sun, in valleys or mountainous hillsides.

Argentina (Catamarca, Córdoba, La Rioja, Salta, San Luis, Tucumán).

Currently 5 recognised species:
– Acanthocalycium ferrari* – Rausch 1976 (=A. variiflorum nom. invai.)
– Acanthocalycium glaucum*  – F. Ritter 1964
– Acanthocalycium klimpelianum* – (Weidl. & Werderm.) Backeb. 1935 (= A. peitscherianum)
– Acanthocalycium spiniflorum* – (K.Schumann.) Backeberg 1935 (= A. violaceum)
– Acanthocalycium thionanthum* – (Spegazzini) Backeberg 1935

References: “TAXONOMY of the CACTACEAE” – ISBN 978-84-617-3723-9 (Vol. 1)