Lobivia saltensis
Echinopsis or Lobivia saltensis) is a very interesting but variable species with several forms and variety.
Habit: It is a small cactus, usually solitary, or heavily clustering.
Flowers: Pretty, shining, small up to 5 cm long, unscented, somewhat bell-shaped-bulgy, dark orange-red or crimson that appears almost black when starting to open. The stamen's filaments are dark red and bear cream-white contrasting anthers. The stigma lobes are greenish.
Blooming season: The greater part of flowers appears in spring in the first flowering, but the plant can erratically produce some flowers in summer too.
Cultivation and Propagation: This is a much decorative frost hardy cactus easily found in cultivation. It is a summer grower species that offers no cultivation difficulties.
Water: In summer, during the vegetative period, it must be regularly watered, but allowing the substratum to completely dry up before irrigating again (but do not overwater ); in winter, it’s to be kept dry. Preferable not to water on overcast days, humid days or cold winter days.
Hardiness: It is a quite frost resistant cactus, hardy to -5° C (- 10° C if very dry
Exposure: Outside full sun or afternoon shade, inside needs bright light, and some direct sun, but, as a former mountain dweller, does not care for extremely high temperatures in summer.

Some of the information in this description has been found at desert-tropicals.com, llifle.com and cactus-art.biz

Bloom Season	Spring and summer
Botanical Name	Lobivia saltensis
Dormancy	Winter
Family	Cactaceae
Flower Color	Scarlet (dark red)
Mature Size	Under 6 in. (15 Cm)
Native Area	Argentina
Resistance	5° C ( 10° c if very dry)