Plant of the Week: Addison's Leather Flower (Clematis addisonii)

This beautiful native, small vine, is only known to occur in four western Virginia counties in dry woods, openings, and rock outcroppings with calcareous soils.  It only grows here because it is found on a unique geological formation called the Elbrook formation, which is mostly dolomite with some limestone, shale and siltstone. While this native habitat is about 5 hours from Lexington, it is only a couple hours east of the Kentucky border and it does very well here in Kentucky because of our calcareous (limestone based) soils and being pretty much at the same latitude on the map.  It has just begun flowering here and it is such a smallish, delicate vine, reaching about 2 to 2.5 feet tall, with very smooth leaves and one plant I observed had over a dozen of the characteristic bluish purplish white tipped urn shaped flowers dangling from purplish stems.  Like most climbing clematis or American bells, the stems are pretty fragile and the leaves are simple, not complex.  The plant dies back each winter and then begins vigorous growth in the spring.  Given the right conditions it will flower all summer long.  It likes part sun but can take full sun or a good bit of shade and the more sun, the more it flowers.  It likes well drained soil (no clay) and does like rich soils but can do okay without them.   This plant was named for Addison Brown, one of the founders of the New York Botanical Garden.  The two nurseries I know that carry this species are Plant Delights and Brushwood Gardens, but they typically sell out of this species quickly each year because it is such a great plant.  Try growing it along a woodland border sprawling around some of the skullcaps (Scutellaria), butterfly milkweed, coreopsis, and other shorter growing full sun species or make it a specimen plant and put in two or three for a magnificent show.