Bupleurum rotundifolium 'Griffithii' is an excellent foliage plant with flowers that are green and Euphorbia like and leaves that are like that of Eucalyptus.
It's a great foil for other flowers and grows to 60cm tall with a spread of 30cm. Germination can be erratic but it is worth sowing as they contrast well with other flowers and are a great bouquet fillers. Looks striking when set against orange Calendulas and other bright flowers.