Mother-in-law's tongue is the very mean nick-name for this common plant, otherwise known as 'Snake's tongue'. A very hardy succulent, I think it makes an attractive live fence. Known as NaagataaLi in Kannada, the sap from the 'tongue' is supposed to be a cure for ear ailments.
The 'tongue' in this type usually takes a twist or two and has a nice spiral shape.
All the three above have their origins in my mother's garden. She had a huge collection of succulents.....
Ah! I can now be accused of holding the mother-in-law's tongue!
(Strictly tongue-in-cheek statement, that one!)
Actually, instead of offending mothers-in-law & snakes, we should be calling it by the unimaginative 'green tongue'. But, there's a hitch here. I have seen a variety where the 'tongues' are a beautiful shade of purple-green. The tip is very sharp... 'blade tongue', perhaps? 'Sword plant' because it looks like a sword???
Anyway, a tough, hardy plant that can adapt itself to suit any condition....whatever the name!