'Silver Spectre' Corydalis
The basic information available from growers & nurseries for 'Silver Spectre' as a cultivar of Corydalis leucanthema may be completely incorrect. All the growers repeat the same assertion as to its species identity & all insist it is an alpine corydalis. But in 2002, I heard from Magnus Liden of the Upsala University Botanic Garden in Sweden, who is certain the identification is wrong.
Magnus is an authority on the genus, having co-authored Corydalis: A Gardener's Guide & a Monograph of the Tuberous Species, & personally grows fifty or more different species of Corydalis. Upon viewing my 'Silver Spectre' page, he informed me he does not believe the species identification is correct, saying:
"You grow a very strange Corydalis species that I cannot immediately recognize. It is definitely not Corydalis leucanthema, but resembles C. longicalcarata. Neither of them is alpine, however, as you claim your plant to be."
It certainly would not be unusual for growers & retailers to sell a plant under an incorrect name. I know of instances of plants being sold with the wrong indentification for many years, & when the error at long last became known, it was just too much trouble & expense to correct the manufactured labels, so the misinformation is perpetuated. For a clear example, see the page about Veronica umbrosa, a blue creeping veronica sold everywhere as V. peduncularis due to a very longstanding misidentification that began with no less than Kew Gardens itself.
Magnus could not from pictures alone correct the identification. He generously offered to trade me rare corydalises for a start from my clump, but mine was at that time still only a tiny thing that could not be divided. I only recently (in 2004) was able to get tubers from it to send to Magnus, & am at the moment waiting to hear if he still needs them & if laws will permit me to airmail live roots to Sweden. I hope eventually, with Magnus's expertise, to be able to reveal the actual species for this long-misidentified corydalis.
For the time-being Corydalis leucanthema 'Silver Spectre' I will call only Corydalis sp. 'Silver Spectre.' It was evergreen in our garden for its first & second winter, protected underneath the paperbark maple along with May apples, a rapidly spreading mouse plant, a 'Pink Bouquet' Tiarella, & other such shade-loving plants.
It was quietly dormant in winter but without much die-back, & it did not estivate during summer, though had it not been kept scrupulously moist it probably would have. Puget Sound weather is so moderate, such plants as are expected to have die-back periods can sometimes keep many of its leaves throughout all seasons.
Its second summer & third winter, however, it did die back, as there'd been both an unsually hot summer & an unusually cold winter. I even worried it was dying. It returned a little bit in October & more noticeably in November, then went winter-quiet, & more seriously but slowly showed fresh new leaves in March, with a couple flowers before March's end. Perhaps this is a normal pattern for 'Silver Spectre' (it is normal for many other corydalises) but the fact that it had formerly been nearly evergreen with a perpetual presence even in summer & winter led me to fear something had gone wrong.
It had seemed to me that after two full years in the garden & onto its third, it should have spread more. The tiny clump hadn't spread at all, causing me (mistakenly it turned out) to suspect it wasn't taking hold very well, but was barely hanging on.
I had planted another species of corydalis nearby, a hybrid called 'Blackberry Wine,' & in a single year that one had spread so rapidly that it was becoming a threat to the restrained 'Silver Spectre.' Furthermore, the flower colors were so similar to that of 'Silver Spectre' that the smaller plant would never be able to show itself to best effect with domineering 'Blackberry Wine' hovering over it. I wouldn't have planted such a similar plant in the same area if I hadn't jumped to the conclusion that 'Silver Spectre' was fading out of the garden in any case. When it made an obvious return in spring only to be threatened by a more vigorous corydalis, I knew I had to transplant it.
So late in March (2004), its third spring in our garden, I dug up the little 'Silver Spectre' to move to a new bright-shade garden that had only recently been prepared behind a stacking-stone wall. This is a raised garden above a newly laid flagstone patio. Dappled shade is provided by a sweet cherry.
When I began to dig up the 'Silver Spectre,' imagine my amazement that despite its slow growth-rate above-ground, it had been producing lots of miniature dahlia-like tubers, some very tiny, some a slender two or three inches long.
I'm sure I missed some of them, & 'Silver Spectre' will continue to erupt in its old location, but the majority of the loose cluster of tuber-swollen roots I was able to transplant. It was hardly necessary to separate the tubers, as they dangled on very loose thin threads & came apart in my hand. So the previous location which was at most a six inch wide clump was separated into the new location into an area two foot by one foot area. I keep my fingers crossed that I will actually at long last have a good width of groundcover from this beautiful plant.
Despite a perpetual presence in the garden, it had seemed a little delicate to me because of the continuing smallness of the original clump, & even in its third year I'm still a little uncertain how well it will do. Even as a delicate little clump it flowers nicely, but I want it to cover enough ground to be noticeable without having to remember to look for it.
Our other Corydalis & Dicentra species are almost aggressive at spreading out their territory or self-seeding into unexpected locations. By comparison, it looked to me like 'Silver Spectre' had shrunk over time, until in transplanting it I suspected instead that it had been expending all its energy on its tubers. I have sometimes wondered if it might be one of the Corydalses that prefer a slightly alkaline soil, or if I am even now missing some significant ingredient to make it really pick up its above-ground growth.
In 2002 still in its old location, the first flowers of the year began in March (that's when the photo above was shot) & continued to flower through June, with a second flourish of blossom for Autumn. The flowers are colored lavender, white, & purple, forming in clusters above the foliage. It has never been extremely flowery, only producing a few flowers at any given time, but those few flowers were quite long-lasting.
New growth on 'Silver Spectre' emerges green with a slight frosty appearance down the center of each leaf, but ages into a fuller dusting of shimmering metallic silver. It has one of the most stunning of all corydalis foliages, pleasing even when not in flower.
If the growers had been correct in identifying it as C. leucanthema, then this would be an alpine plant native of China, very cold-hardy & reliable, liking best temperate weather. Since the identification is incorrect, however, it may come from an environment quite different from the one I've tried to provide it in our gardens. I'll revise this page again as I am able to observe its behavior in its new location under the sweet cherry.