This section is from the book "The Native Flowers And Ferns Of The United States ", by Thomas Meehan. Also available from Amazon: The Native Flowers and Ferns of the United States in Their Botanical, Horticultural, And Popular Aspects.
Sepals ovate-lanceolate; lip white, flatfish laterally, convex above; sterile stamen lanceolate; leaves lance-oblong, acute. Plant a little larger than Cypripedium arietinum, slightly pubescent, one-flowered; petals and sepals greenish, not much exceeding the lip, which is less than one inch long. (Gray's Mannal of the Botany of the Northern United States. See also Wood's C/ass-Book of Botany.)
THE flower now known as Cypripedium was formerly "Our Lady's Slipper," and is known to the moderns as Venus' Slipper, Shoe or Sock. The flowers have some resemblance to a shoe, but most probably if Venus had the same regard for a neat fit as characterizes the ladies of our time, she would not feel complimented by the selection of a shoe- like this for her. The style is much more suited to an Indian's foot. It resembles a moccasin more than anything the Goddess of Beauty could be supposed to wear. It is commonly known as the moccasin flower, and for the reason above given we have adopted the name as our leading common one.
Most moccasin flowers of the United States grow in thin woods or partially shaded places, but the "White Moccasin Flower" here illustrated is found in somewhat more public situations. It is the only one which seems at home in the open prairie, on which, indeed, very few orchideae grow. The Rev. Mr. Greene tells us, in the third volume of the "American Naturalist," that on the prairies of Illinois only three orchids arc found, and of these Cypripedium candidum, our white moccasin flower, is one. From its general place of growth it is probably the kind referred to by Bryant in his touching poem, " The Maiden's Sorrow ":
" Seven long years has the desert rain Dropped on the clods that hide thy face; Seven long years of sorrow and pain I have thought of thy burial-place.
"Thought of thy fate in the distant West, Dying with none that loved thee near; They who flung the earth on thy breast Turned from the spot without a tear.
" There, I think, on that lonely grave,
Violets spring in the soft March shower; There, in the summer breezes, wave Crimson phlox and moccasin flower."
White flowers are generally selected as emblems of purity, and are used as tributes alike at marriages and funerals, both to the birth and to the death of love. The Cypripedium candi-dum is our only white species, and whether it actually was or not the "moccasin flower" in Bryant's mind, it is of all the most fitted to deck a maiden's lonely grave.
The white moccasin flower has been known to botanists only within a comparatively recent date. Muhlenberg, the distinguished Pennsylvanian, records it in his "Catalogue," published in 1813, and gives Pennsylvania as the only State in which it was then known to exist. Rafinesque, writing in 1826, gives Ohio in addition to Pennsylvania, and we see how limited must have been the knowledge of it even in that time. Dr. Asa Gray, in his "Manual of Botany," says it is now found from Central New York to Kentucky and Wisconsin. Of special locations, of which we have records before us while writing, we find it is found in Ohio, Nebraska, Southern Michigan, Iowa, Indiana and Illinois. Its central home may perhaps be considered as Michigan and Iowa, - at least in these States it grows in considerable abundance.
The distribution of orchids over the surface of the globe is one of the interesting subjects just now specially attracting the attention of botanists. Many species of this family are wholly dependent on insect aid for the fertilization of their flowers. It is believed that it is better for species or race that the individual plant should be occasionally, at least, crossed rather than perpetually to receive its own pollen. In view of these prevalent opinions, it may be noted that orchids, dependent on insect aid, are not often widely distributed in comparison with other plants, and notes of the disappearance of species from some localities are not uncommon. In regard to our present subject, the White Moccasin Flower, Dr. J. Schneck tells us, in the report of the "Indiana Geological Survey," that it seems to be gradually disappearing from the flora of the Lower Wabash region. Mr. Darwin tells us, in his charming work, "On the Fertilization of Orchids," when writing of Cypripedium, that "an enormous amount of extinction must have swept away a multitude of intermediate forms, and has left this single genus, now widely distributed, as a record of a former and more simple state of the great orchidaceous order." Some orchids now existing fertilize them-selves, and it would be an interesting point to decide whether these departed species were of this class, and chiefly only those which had the benefit of cross-fertilization endured. But it is a fact worth noting by the student that, even with this supposed benefit, probably more species will be marked in our works on botany "rare" among orchids than among any other tribe of plants.
The white moccasin flower has been of use to botanists by affording, through variations, some key to the real structure of the orchideous flower. Mr. Darwin quotes Professor Asa Gray as saying, of "a monstrous flower of Cypripedium candiduni, 'here we have (and perhaps the first direct) demonstration that the orchideous type of flower has two staminal verticils, as Brown always insisted.'" By this is meant that orchids were primarily designed to have six stamens in verticils of three each, but the tendency in orchideae is to unite these primordial parts into a single column, resulting in these odd-shaped flowers. The study of these malformations is called teratology, and it has become one of the most interesting branches of botanical science, as by its aid many problems in plant structure are explained. In the light of teratology malformations in orchideous plants are particularly interesting to the student, and, when observed, should be carefully preserved. Our present species is well worth watching for them. In the first vol. "Botanical Gazette," page 34, Mr. Herbert E. Copeland says: "Bearing on the proof of intergrading of parts are wild double flowers. It is not unknown that the best efforts of the florist are often anticipated in the woods. I have three specimens of Cypripedium candidum with two lips each, at the expense of the sepals of course," and we may add that in the hands of the vegetable morphologist such a specimen has an inestimable value.
Cypripedium candidum grows generally in open boggy places, and flowers in May and June. The drawing was made from a specimen collected in Nebraska by the author.