– Echinocactus graessneri K. Schumann 1903,
– Malacocarpus graessneri (K. Schumann) Britton & Rose 1922,
– Notocactus graessneri (K. Schumann) A. Berger 1929,
– Brasilicactus graessneri (K. Schumann) Backeberg 1942,
– Parodia graessneri (K. Schumann) F. H. Brandt 1982,
– Parodia haselbergii subsp. graessneri (K. Schumann) Hofacker & P. J. Braun 1998,
Plants solitary, globose, bright to gray-green, somewhat depressed apically, 7-8 cm (2.8-3.1 in) in diameter. Ribs 30 or more, somewhat tuberculate, spirally arranged. Areoles white. Central spines 3-5, yellowish, 10-15 mm (0.4-0.6 in) long. Radial spines 20 – 60 or more, needle-like, almost bristly, yellowish white, to 10 mm (0.4 in) long. Flowers yellowish to yellowish green, 2.5-3 cm (1-1.2 in) in diameter floral tubes short or absent; pericarpels and floral tubes with small scales, wool, and bristles. Fruits not known.
Distribution: Rio Grande do Sul, Brazil.
“Spiny head”, because the genus is completely covered with spines. • DESCRIPTION
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. • HABITAT
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. • DISTRIBUTION
Brazil (Rio Grande do Sul).