We have yet to see a spring squill that is not beautiful, and the Caspian bluebell is surely among the most beguiling. Clusters of large light purple-blue flowers – whose segments reflex to reveal black anthers – open on 4-inch stems in late winter. Each segment is ornamented with a sky-blue midrib, which adds a final note of beauty and elegance. Steppe/Montane; Caspian region. Zone 5.