Herbs, well marked by the peculiar arrangement of the stamens, these being gynandrous, that is, borne on oradherent to the stigma or style. There is also usually but a single stamen, of two rather widely separated anthers, but in the last genus of the following list there are 2 distinct stamens, with the rudiment of a third at the back of the stigma. As explained in Part I., sections 90-93, the Orchids as a rule require the aid of insects to convey the pollinia, or pollen-masses, to the stigma, but occasionally it happens that when the anther-cells burst open the pollinia fall forward and dangle in front of the viscid stigma beneath, being sooner or later driven against it either by the wind or by the head of some insects in pursuit of honey. In all cases where the student meets with an Orchid in flower, he should, by experiment, endeavour to make himself acquainted with the method of its fertilization.
The Orchis family is a very large one, there being probably as many as 3,000 different species, but the greater number are natives of tropical regions. Many of them are epiphytes, or air-plants, deriving their support chiefly from the moisture of the air, through their long aerial roots which never reach the ground. The perianth in many species, and particularly the labellum, or lip, assumes the most fantastic shapes, making the plants great favourites for hot-house cultivation. In Canada the representatives of this great Order, though not very numerous, are among the most interesting and beautiful of our wild flowers. They are, as a rule, bog-plants, and will be found in flower in early summer.
* Anther only one, but of 2 cells, these separated in the first genus. + Lip with a spur underneath. Anther on the face of the stigma..
1. Orchis. The 3 sepals and 2 of the petals erect and arching over the centre of the flower; the lip turned down. The 2 glands or viscid disks of the base of the pollen-masses enclosed in a little pouch just over the concave stigma. Leaves 2, large. Flowers few, in a spike.
2. Hahenaria. The lateral sepals usually spreading. The glands or viscid disks of the pollen-masses not enclosed in a covering. Flowers in spikes.
+ + Lip without a spur. Anther on the back of the column. + + Flowers small, white, in a slender spike.
3. .Spiran'thes. Spike (of white or whitish flowers) more or less spirally twisted. Sepals and petals narrow and generally connivent. Lip oblong, the lower part embracing the column, and with a protuberance on each side of the base.
4. Goodye'ra. Flowers very much as in Spiranthes, but the lip sacshaped, and without protuberance at the base. Leaves white-veiny, in a tuft at the base of the scape.
+ + + + Flowers racemose, varying from greenish-yellow to purple. Stem very leafy.
5. Epipac'tis. Stem 1-2 feet high, stout, leafy. Leaves broadly ovate, the upper narrower. Sepals and petals nearly equal, spreading. Lip deeply concave at the base, constricted and somewhat joined in the middle, dilated and petaloid above. Anther sessile behind the stigma, on a slender-jointed base. Ovaries reflexed at maturity.
+ + + Lip without a spur. Anther on the apex of the style, hinged like a lid.
+ + Pollen-masses 2 or 4, powdery or pulpy, without stalk or gland.
6. Lis'tera. Flowers small, greenish or brownish-purple, in a spike or raceme. Stem bearing a pair of opposite sessile roundish leaves near the middle. Lip flat, mostly drooping, 2-lobed at the apex.
7. Calopo'gon. Ovary not twisted,thelipconsequently turned towards the stem. Flowers large, pink-purple, 2-6 at the summit of the scape; the lip spreading at the outer end, and beautifully bearded above with coloured hairs. Leaf grass-like, only one. Pollen-masses 4.
8. Arethu'sa. Flower solitary, large, rose-purple. Lip dilated, recurved,.spreading at the end. Sepals and petals lanceolate, nearly alike, arching over the column. Pollen-masses 4. Scape low, sheathed, from a globular solid bulb, with a single linear-nerved leaf hidden in the sheaths of the scape.
9. Pogo'nia. Flower solitary, irregular, large, sweet-scented, pale rose-colour or white. Column club-shaped. Lip crested and fringed. Pollen-masses 2. Stem 6-9 inches high, with a single oval or lance-oblong leaf near the middle, and a smaller one, or bract, near the flower.
+ + + + Pollen-masses 4, smooth and waxy, attached directly to a large gland: no stalks.
10. Calyp'so. Flower solitary, large, showy, variegated with purple, pink, and yellow. Lip large, inflated, sac-shaped, 2-pointed under the apex. Scape short, from a solid bulb, with a single ovate or slightly heart-shaped leaf below.
++ ++ ++ Pollen-masses 4: no stalks or glands.
11. Micros'tylis. Small herbs from solid bulbs; the scape bearing a single leaf and a raceme of minute greenish flowers. Column very small, terete, with 2 teeth at the top, and the anther between them. Petals thread-like or linear,spreading.
12. Lip'aris. Small herbs from solid bulbs; the low scape bearing 2 radical leaves and a raceme of a few greenish flowers. Column elongated, incurved, margined at the apex. Petals thread-like or linear, spreading. Anther lid-like.
13. Corallorhi'za. Brownish or yellowish plants, with the small dull flowers in spikes or scapes which are leafless or have mere sheaths instead of leaves. Rootstocks branching and coral-like. Perianth gibbous or slightly spurred below. Lip with 2 ridges on the inner part of the face.
14. Aplec trum. Somewhat like the last, but the perianth is not gibbous below, and the rootstock, instead of being coral-like.is slender, and produces each year a solid bulb or corm. Lip with 3 ridges on the palate. Scape with 3 greenish sheaths below.
** Anthers 2, one on each side of the stigma, and a triangular body, which is the rudiment of a third, at the back of the stigma. Pollen loose and powdery or pulpy.
15. Cypripe'dium. Lip a large inflated sac, into the mouth of which the style is declined. Sepals and the other petals much alike, the former apparently only 2, two of them being generally united into one under the lip. Leaves large, many-nerved. Flowers solitary or few.