Collecting Corydalis can be fun, fascinating and frustrating. I began about five years ago with a local species. Seeking more information in garden books, I found there was a wide selection to choose from. I began checking catalogs for availability and price.
There is a great deal of conflicting information, both in catalogs and literature. Sweeping general statements are made, lumping all species under the same umbrella for planting sites. That may help simplify the selling, but some Corydalis species will be lost in the garden if all are treated the same when planting. Descriptions found in catalogs and some references are confusing at best. I have found the same description, obviously from a single original source, being applied to two, or more, different species.
I am not the person to right all wrongs in the world of Corydalis. I have neither the qualifications, time, nor desire. The ideal here is an introduction to a fine family of flowers, one genus in particular, and some selected species.
Literature may list the genus Corydalis in either the Poppy or Fumitory Family, with most of my books saying Fumariaceae. Over three hundred annual and perennial species grow in the Northern Temperate Zone. Central Asia and Western China, along with some in South Africa, have the heaviest concentrations. Only the perennial species are of interest here, still leaving a wide list of plants to choose from for the garden.
The genus has probably not gained in popularity any more than it has to do due to difficulty in propagation. Seed ideally should be fresh (not having dried out from storage). Germination is generally erratic. Corydalis may have tubers or rhizomes and resent disturbance when very young. Either sow them in the desired location or thinly plant in pots where they can grow on for the first year before transplanting.
Having gone on about all the difficulties of finding plants or seed, the germination or propagation, it should also be emphasized that all is worth the efforts. Corydalis will perform well where few other perennials survive. Once established they do generally seed themselves about in the garden. Many species do well in lean soil, rock walls and crevices. Some species will only thrive in dry rocky shade.
There are two species growing in the wild here in the heartland. C. flavula, the yellow corydalis, is a small plant of six to twelve inches with pale yellow flowers. If you are not familiar with Corydalis then think of your grandmother's Bleeding Hearts for they both have similar foliage.
This one blooms and germinates in winter and does it ever germinate! It sets prolific seed and I would not recommend bringing this species into the garden unless you have a large relaxed woodland setting. It will get into, under and in-between every other plant in the garden.
C. sempervirens, the pink corydalis, is our second species. Flowers are the typical four petals with two being much longer than others. There is a sack-like spur on one of the two larger petals. Corydalis is Greek for Lark, referring to the spur on both flower and bird's foot. Both of our native species have gray-green leaves, typically compound and divided. Height is a bit larger, coming in at just over a foot. Habit is more open and lax when the species gets much beyond that height. Flower color is pink with yellow tips and by far the most attractive of the two so far described.
C. lutea, the European yellow corydalis, is probably the most popular and well known. Corydalis lutea is very close to evergreen in this area. Reaching about a foot in height, it is bushy and dense with small leaves. Foliage is green on the upper surface, bluish-green underneath. Flowers are held in small dense clusters of golden yellow. It begins blooming early in the season and continues blooming until around October. I consider it a workhorse for the garden.
 Corydalis solida |
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C. bulbosa is really C. solida, bulbosa being a rejected synonym for solida. Most catalogs list this plant as solida. This Corydalis is a real cutie. It emerges in very early spring, one stem to the tiny tuber, blooms and is soon dormant. Foliage is less than six inches in height. The plant is practically covered in blooms. Color can vary and there are named cultivars. The one usually received is a soft rose-lavender or purple. Be sure and buy a bunch for they look best in drifts of six or more.
C. ochroleuca closely resembles C. lutea in foliage and size. Blooms are a pale cream, the petal tips a darker butter-yellow. Mine are growing in a rich alpine mix and performs well. It seems to perform best in dry shade among rocks and crevices. Coming into bloom in mid-March it will continue to bloom until it is hit hard by a freeze in October or November. It is semi-evergreen for me
There are quite a few other species of Corydalis that show up from time to time on seed lists and collectors catalogs. A few are as temperamental as a symphony conductor, but most are relatively easy to grow and well worth seeking.