This section is from the book "Nature's Garden", by Neltje Blanchan. Also available from Amazon: Nature's Garden; An Aid To Knowledge Of Our Wild Flowers And Their Insect Visitors.
Flowers - Pink-purple and pale lilac, sometimes nearly white; fragrant, alternate, clustered in thick, dense spikes from 3 to 15 in. long. Upper sepal and toothed petals erect; the lip of deepest shade, 1/2 in. long, fan-shaped, 3-parted, fringed half its length, and prolonged at base into slender, long spur; stamen united with style into short column; 2 anther sacs slightly divergent, the hollow between them glutinous, stigmatic. Stem: 1 to 5 ft. high, angled, twisted. Leaves: Oval, large, sheathing the stem below; smaller, lance-shaped ones higher up; bracts above. Root: Thick, fibrous.
Flowering Season - June - August.
Distribution - New Brunswick to Ontario; southward to North Carolina, westward to Michigan.
Because of the singular and exquisitely unerring adaptations of orchids as a family to their insect visitors, no group of plants has greater interest for the botanist since Darwin interpreted their marvellous mechanism, and Gray, his instant disciple, revealed the hidden purposes of our native American species, no less wonderfully constructed than the most costly exotic in a millionaire's hothouse.
A glance at the spur of this orchid, one of the handsomest and most striking of its clan, and the heavy perfume of the flower, would seem to indicate that only a moth with a long proboscis could reach the nectar secreted at the base of the thread-like passage. Butterflies, attracted by the conspicuous color, sometimes hover about the showy spikes of bloom, but it is probable that, to secure a sip, all but possibly the very largest of them must go to the smaller purple-fringed orchis, whose shorter spur holds out a certain prospect of reward; for, in these two cases, as in so many others, the flower's welcome for an insect is in exact proportion to the length of its visitor's tongue. Doubtless it is one of the smaller sphinx moths, such as we see at dusk working about the evening primrose and other flowers deep of chalice, and heavily perfumed to guide visitors to their feast, that is the great purple-fringed orchid's benefactor, since the length of its tongue is perfectly adapted to its needs. Attracted by the showy, broad lower petal, his wings ever in rapid motion, the moth proceeds to unroll his proboscis and drain the cup, that is frequently an inch and a half deep. Thrusting in his head, either one or both of his large, projecting eyes are pressed against the sticky button-shaped disks to which the pollen masses are attached by a stalk, and as he raises his head to depart, feeling that he is caught, he gives a little jerk that detaches them, and away he flies with these still fastened to his eyes.
Even while he is flying to another flower, that is to say, in half a minute, the stalks of the pollen masses bend downward from the perpendicular and slightly toward the centre, or just far enough to require the moth, in thrusting his probosis into the nectary, to strike the glutinous, sticky stigma. Now, withdrawing his head, either or both of the golden clubs he brought in with him will be left on the precise spot where they will fertilize the flower. Sometimes, but rarely, we catch a butterfly or moth from the smaller or larger purple orchids with a pollen mass attached to his tongue, instead of to his eyes; this is when he does not make his entrance from the exact centre - as in these flowers he is not obliged to do - and in order to reach the nectary his tongue necessarily brushes against one of the sticky anther sacs. The performance may be successfully imitated by thrusting some blunt point about the size of a moth's head, a dull pencil or a knitting-needle, into the flower as an insect would enter. Withdraw the pencil, and one or both of the pollen masses will be found sticking to it, and already automatically changing their attitude. In the case of the large, round-leaved orchis, whose greenish-white flowers are fertilized in a similar manner by the sphinx moth, the anther sacs converge, like little horns; and their change of attitude while they are being carried to fertilize another flower is quite as exquisitely exact.
Usually in wetter ground than we find its more beautiful big sister growing in, most frequently in swamps and bogs, the Smaller Purple-fringed Orchis (H. psycodes) lifts its perfumed lilac spires. Thither go the butterflies and long-lipped bees to feast in July and August. Inasmuch as without their aid the orchid must perish from its inability to set fertile seed, no wonder it woos its benefactors with a showy mass of color, charming fringes, sweet perfume, and copious draughts of nectar, and makes their visits of the utmost value to itself by the ingenious mechanism described above. Here is no waste of pollen; that is snugly packed in little bundles, ready to be carried off, but placed where they cannot come in contact with the adjoining stigma, since every orchid, almost without exception, refuses to be deteriorated through self-fertilization.
From New Jersey and Illinois southward, particularly in mountainous regions, if not among the mountains themselves, the Fringeless Purple Orchis (H. peramoena) may be found blooming in moist meadows through July and August. Moisture, from which to manufacture the nectar that orchids rely upon so largely to entice insects to work for them, is naturally a prime necessity; yet Sprengel attempted to prove that many orchids are gaudy shams and produce no nectar, but exist by an organized system of deception. "Scheinsaftblnmen" he called them. From the number of butterflies seen hovering about this fringeless orchis and its more attractive kin, it is small wonder their nectaries are soon exhausted and they are accused of being gay deceivers. Sprengel's much-quoted theory would credit moths, butterflies, and even the highly intelligent bees with scant sense; but Darwin, who thoroughly tested it, forever exonerated these insects from imputed stupidity and the flowers from gross dishonesty. He found that many European orchids secrete their nectar between the outer and inner walls of the tube, which a bumblebee can easily pierce, but where Sprengel never thought to look for it. The large lip of this orchis is not fringed, but has a fine picotee edge. The showy violet-purple, long-spurred flowers are alternately set on a stem that is doing its best if it reach a height of two and a half feet.