Acanthocalycium thionanthum

Acanthocalycium thionanthum
(Spegazzini) Backeberg 1935

  • – Echinopsis thionantha – (Spegazzini) Werdermann 1931
    – Echinocactus thionanthus – Spegazzini 1905,
    – Lobivia thionantha – (Spegazzini) Britton & Rose 1922,
    – Echinocactus chionanthus – Spegazzini 1905,
    – Lobivia chionantha – (Spegazzini) Britton & Rose 1922,
    – Echinopsis chionantha – (Spegazzini) Werdermann 1931,
    – Acanthocalycium chionanthum – (Spegazzini) Backeberg 1935
    – Acanthocalycium griseum –  Backeberg 1963, not validly published
    – Acanthocalycium brevispinum – F. Ritter 1964,
    – Echinopsis brevispin (F. Ritter) – H. Friedrich & G. D. Rowley 1974
    – Acanthocalycium catamarcense = F. Ritter 1980

Plants usually solitary, globose to short cylindrical, dark green to gray-green, to 12 cm (4.7 in) high and 10 cm (3.9 in) in diameter. Ribs 9-15, round, slightly notched and tuberculate. Areoles elliptical. Spines awl shaped, gray with dark tips, 1-1.5 cm (0.4-0.6 in) long. Central spines 1—4, sometimes absent. Radial spines 5-10. Flowers somewhat bell shaped, bright yellow to red to white, to 4.5 cm (1.8 in) long and in diameter; pericarpels and floral tubes with dark, spine-tipped scales and brown to white hairs and bristles. Fruits globose, dehiscent, hard, to 1 cm (0.4 in) in diameter.

Distribution: Salta, Argentina.

References: Anderson E.F. - The Cactus Family 



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)