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Lady's Slipper

Cypripedium longifolium OUR lady's slipper is the hardy Cypripedium calceolus, which is dedicated to St. Etheldreda. Strictly speaking there is no other lady's or "ladies" slipper, and the familiar generic name of this group of orchids is therefore, in a certain sense, apocryphal. But the world has its own way in disposing of such matters, and we do not intend to darken these pages with any dry discussion.

The cypripediums are the most attractive of all the orchids for the earnest student of plant form, because they illustrate in the most patent manner the true theory of the construction of an orchid. On this point a few remarks may be at once useful and interesting. An orchid flower consists of fifteen parts, in five series of three each. To find these will rarely be an easy task, for all kinds of variations are played by Nature on the ever-ruling simple tune. But in the study of an orchid, the five series of three each must be sought, and if not found, must be in some way accounted for. Here is the true architectural theory-three sepals, three petals, three stamens, three pistils, and three carpels. In the orchid before us the topmost piece, or banner, is a sepal; and the question arisen, Where are the other two ? They are united, and partly hidden behind the pouch, or labellum : that is to say, as one sepal forms a banner above, the other two conjoined form an apron beneath the centre piece, or slipper. The two side pieces are petals, and the slipper, or pouch, or labellum, is also a petal. Amongst all the orchids, the cypripediums stand alone in respect of their production of three stamens; but here is another difficulty, for the casual eye can find but two, which are placed right and left of the column. Where is the third? It is sterile, and placed between the other two. The three stigmas are confluent, and appear as one below the anther, being called the stigma in descriptions, because of its evident existence. As for the three carpels of which the ovary consists, these will appear only as the result of fertilisation, and at a later stage in the history of the flower.

The singular structure of the orchids inspired the elder Darwin with a song, and the younger Darwin-Charles-with a passion for a special study, the outcome of which was a remarkable book on orchids generally. As regards the uses of the slipper, Mr. Darwin's work is rich in proposals for the careful observer. He says: "Cypripediums " differ from all other orchids. An enormous amount of extinction must have swept away a multitude of intermediate forms, and left this single genus, now widely disseminated, as a record of a former and more simple state of the great orchidean order." Having described the flower, he says: "As the two anthers stand behind and above the lower convex surface of the stigma, it is impossible that the glutinous pollen can get to this, the fertile surface, without mechanical aid. An insect could reach the extremity of the labellum, or the toe of the slipper, through the longitudinal dorsal slit; but, according to all analogy, the basal portion in front of the stigma would be the most attractive part. Now, as the flower is closed at one end, owing to the toe of the slipper being upturned, and as the dorsal surface of the stigma, together with the large shield-like rudimentary anther, almost close the basal part of the medial slit, two convenient passages alone are left for an insect to reach with its proboscis the lower part of the labellum-namely, directly over and close outside the two lateral anthers. If an insect were thus to act-and it could hardly act in any other way-it would infallibly get its proboscis smeared with the glutinous pollen, as I found occur with a bristle thus inserted ... Thus an insect would place either the flower's own pollen on to the stigma, or, flying away, would carry the pollen to another flower.... We thus see how important, or rather how necessary, for the fertilization of the plant is the curious slipper-like shape of the labellum in leading insects to insert their probosces by the lateral passages close to the anthers." The cypripediums alone possess glutinous pollen grains, and with them the peculiar mechanical construction requisite to the accomplishment of fertilisation.

The cultivation of the tender species of Cypripedium is a simple matter where plant growing is fairly well understood. They are terrestrial orchids, requiring a compost of peat, loam, and silver sand, with plenty of water when growing freely. The most generally useful is our old friend C. insigne, which requires a warm greenhouse, and careful management as regards air-giving and shading. The species that require the stove are usually potted in a mixture of sphagnum moss and peat, with a considerable admixture of small crocks. As for the hardy kinds, a shaded and very moist peat bed may be recommended, and if small grasses and other very neat weeds are allowed to grow up with them, there will be no harm done; but coarse weeds must not be allowed. The loveliest of all the hardy orchids is Cypripedium spectabile, the rosy pouch of which is matchless in its colour.