Arums

Arum nigrum Zadar CEH.524

A horrendously stinky species with rounded glossy black spathes in summer, held low among the broad green leaves. 

Very good in dry shade. Long-lived and not invasive. For those who like this sort of thing – this is the sort of thing they like. Or for people you don't like, hide it under a deciduous shrub - they'll never work out where the stench is coming from.
£12

Arum elongatum RS.274/87

A compact species with narrow curved spathes close to the ground - green outside, dark within. Narrow plain green leaves. 

Slow but hardy here in a sunny well-drained spot.

£18