Soehrensia thelegona

Soehrensia thelegona is a species of cactus in the Soehrensia genus.

Description
Soehrensia thelegona grows as a shrub with few branches. The tips of the prostrate to creeping shoots are slightly raised or erect. The cylindrical, dark green shoots have a diameter of 7 to 8 centimeters and are up to 2 meters long. There are about 12 low ribs, which are resolved into conspicuous hexagonal cusps. The areoles on the tips of the humps are circular. Light yellow thorns emerge from them, which turn gray with age and often have a darker tip. The individual central spine protrudes and is 2 to 4 centimeters long. The six to seven needle-like marginal spines are spread out and are 1 to 2 centimeters long. The lowest marginal spines are the longest.

The funnel-shaped, white flowers open at night. They are up to 20 centimeters long and have a diameter of 15 centimeters. Its flower tube is covered with reddish bristles and hairs. The spherical to egg-shaped, yellowish to reddish fruits are tuberous and tear open. They have a diameter of up to 5 centimeters.

Distribution
It is native to north western Argentina and can be found in a small range that occurs in the provinces of Tucumán, Salta and Jujuy at altitudes of 500 to 1000 meters.

Taxonomy
The first description as Cereus thelegonus by Frédéric Albert Constantin Weber was published in 1897. The specific epithet thelegona is derived from the Greek words thele for 'wart' and gonia for 'edge' and refers to the tuberous ribs of the species. It was first published as Soehrensia thelegona in Cactaceae Syst. Init. vol.28: 31 in 2012 by Boris O. Schlumpberger. Further nomenclature synonyms are Trichocereus thelegonus (F.A.C.Weber) Britton & Rose (1920) and Echinopsis thelegona (F.A.C.Weber) H. Friedrich & G.D. Rowley (1974).