C. robusta. This exotic looking subject grows strongly in a shelteredand rich moist soil, not too alkaline. The are fleshy, with a central crown and radiating thongs, active only 2 inches-deep and in cold districts a little covering from November to March is advised in case of severe frost. In early summer the reddish sheathed shoots develop to open out rather like compact growing ‘Sweetcorn’ but in July the yellow lipped make quite a show against a back-cloth of lush greenery. Depending somewhat on moisture, height varies from 2/2 to 4 feet’ and where happy there is an attractive until well into autumn. Planting is best in spring and care must be taken not to injure the rather brittle roots and crowns.