H. herminiae looks a lot like H. salicornoides and also grows upright but doesn't quite have the same little stems segments. What is unique about this species is its deep rose-pink flowers. The rose photo (35mm slide) was obtained by Ken Friedman from Barthlott in the late 1970s; it appears in The Illustrated Encyclopedia of Cacti by Clive Innes and Charles Glass. Innes & Glass say herminiae is best grown as a graft. 

• Body - forming erect shrubs, sometimes arching over.
• Shoots - branching dichotomously or verticillately, cylindric, only slightly thickened above, matt dark green;
• Areoles - . with 1-2 minute bristles.;
• Flowers - mostly solitary, rarely paired, 2 cm long, to 2.5 cm, dark pink;
• Fruit - olive-green, to 8 mm long;
• Seed - chestnut-brown.