Of the many beautiful plants in flower on the Rockwork at Kew, Arnebia echioides is by far the rarest. It is allied to Lithospermum, of which it has much the habit, and the bright yellow flowers are perhaps the prettiest of the color in the order to which it belongs. There are sometimes five purple spots on the corolla, alternating with the lobes, but these are absent in some flowers while present in others on the same plant. It forms a neat tuft, and the flower-stems grow to a height of from six to eight inches.