Introduction
Austrocactus gracilis is one of about 5 or 6 species in the genus Austrocactus. The plants are typically small (less than two-feet tall) and can form small clumps or single columns. The ribs are tuberculate.
The Details
A. gracilis flowers are among the prettiest of the genus, yellow tinged with salmon pink, or sometimes the flowers are pale yellow tinged with a pinkish glow. As with many cacti, the flowers are open in the daytime. Spines are black (centrals) or light (radials). The centrals are hooked.
In The Cactus Family (EF Wilson) calls this species A. bertinii. A. gracilis is found in many dry areas of southern Argentina.
(See the comment below: These photographs may show A. longicarpus, a newly named species that was formerly lumped into A. gracilis.)
The pictures you show belong to Austrocactus longicarpus (described in KuaS 10/2014).
A. gracilis – a form of Austrocactus coxii – has always brilliant yellow flowers, sometimes with orange or brownish tinged petals. Flower form, fruit and seeds also differ.
Thanks for the beautiful pictures and best regards
Norbert
Thanks for the info Norbert. I’ll get around to fixing the text someday.
A. longicarpus has never been lumped into A. gracilis. The plants have been wrongly named.