This wicked looking flower appeared on a cutting brought in from a rue plant I was trying to clone. Ruta graveolens will root from water, but it takes a long time.
I have not verified this yet, but have read that the seeds required light to germinate and that rue should not be planted next to basil Guess I'll have to try that.
See also: Goat's Rue = Galega oficinalis which has blue flower spikes and is in the pea family.