|From Curtis's Botanical Register, 1830|
Disocactus ackermannii is an epiphytic cactus from tropical forests in the states of Veracruz and Oaxaca, Mexico. In cultivation, it has been confused with Disocactus ×hybridus, a hybrid between D. phyllanthoides and D. speciosus.
The stems of Disocactus ackermannii consist of a short rounded base, about 10–18 cm (4–7 in) long, followed by longer flattened leaf-like portions, 10–75 cm (4–30 in) long and 5–7 cm (2–3 in) wide with wavy edges. The plant branches from the base and arches downwards, being altogether some 1 m (3 ft) long. The scarlet flowers have greenish throats and are funnel shaped, 11–14 cm (4.3–5.5 in) long. Fertilized flowers are followed by green to brownish red fruits, 4 cm (1.6 in) long and 2–2.5 cm (0.8–1.0 in) wide.
- Haworth's Epiphyllum ackermannii was successively transferred to Cactus ackermannii (1830), Cereus ackermannii (1837), Phyllocactus ackermannii (1842) and Nopalxochia ackermannii (1935) before the current Disocactus ackermannii (1991).
- Phyllocactus weingartii A.Berger is an independent synonym.
- Nopalxochia conzattianum was named by Thomas Baillie MacDougall in 1947. It was successively transferred to Pseudonopalxochia conzattianum (1959) and Nopalxochia ackermannii var. conzattianum (1981) before the current Disocactus ackermannii var. conzattianum (1991).
Two varieties are currently recognized. D. a. var. ackermannii has longer cladodes (flattened stem portions), 35–75 cm (14–30 in) long, and longer tepals, 7–10 cm (3–4 in) long. D. a. var. conzattianum has shorter cladodes, 10–50 cm (4–20 in) long, and shorter tepals, 4–6 cm (1.6–2.4 in) long.
- Anderson, Edward F. (2001), The Cactus Family, Pentland, Oregon: Timber Press, ISBN 978-0-88192-498-5, p. 222
- Anderson 2001, p. 226
- "RHS Plantfinder - Disocactus ackermannii". Retrieved 12 February 2018.
- "AGM Plants - Ornamental" (PDF). Royal Horticultural Society. July 2017. p. 16. Retrieved 24 January 2018.