Tribe V
CYPRIPEDIEAE. Anthers two, lateral; the rostellum prolonged into a shield between the anthers; pollen powdery. This tribe contains but four genera, only two of which, Cypripedium and Selenepedium, are in cultivation; the first is widely distributed over the temperate and tropical regions of both hemispheres, the latter being confined to the mountainous regions of South America. The two genera not in cultivation, Apostasia and Neuwiedia, are respectively limited to tropical Asia, and Australia and tropical Asia. All four are terrestrial herbs.
Linnaeus, in the middle of last century, only know about a dozen exotic orchids, whereas now, probably, half the known species are, or have been, in cultivation in this country. By far the larger number inhabit tropical forests; they become less plentiful in temperate regions, and are almost absent from very cold ones--perhaps not more than two or three enter the Arctic Circle. They vary exceedingly in size; the Javan Galeola altissima, which has been said to be the largest known orchid, attains a length of more than 100ft.; but a Vanilla has been seen under cultivation with a stem even longer than this. Drymoda picta is one of the smallest of Orchids; it has a dull green, small, disk-like pseudo-bulb, from which springs a minute and very deciduous leaf. Angraecum funale, and some other species of the same genus, as well as some of the African Vanillas, are quite leafless, and depend upon the chlorophyll present in the strap-like roots of the first-named, and in the long stems of the latter genus.
Scarcely any natural order of plants is more free from fungoid attacks than are Orchideae; for what is known about the fungi which have been observed on cultivated Orchids, the reader is referred to a paper by Mr. Worthington G. Smith, in the "Gardeners' Chronicle" (n. s., xxiv. p. 693). This volume also contains an account, by Professor Westwood, of the various phytophagous insects which have been found on imported Orchids. Among some of the other important results of the Orchid Conference of 1885, may be specially mentioned the paper on the Hybridisation of Orchids, by Mr. H. J. Veitch. This also is published in the "Gardeners' Chronicle" (n. s., xxiv. p. 628), and is illustrated by figures of seeds and seedlings of Cypripedium, Dendrobium, and Phalaenopsis. "Of the few orchids which are of use to man, the Vanillas (Vanilla claviculata, planifolia, &c.) hold the first rank. They are sarmentose plants, natives of the hot and damp regions of Mexico, Colombia, and Guiana [and tropical Africa]. Their fruit is a fleshy, long capsule, and the black, globose seeds are enveloped in a special tissue, which secretes a balsamic oil; if kept in a dry place, the capsule becomes covered with pointed and brilliant crystals of benzoic acid, and imparts its delicious perfume to various delicate dishes, chocolates, liqueurs, &c. The Faham (Angraecum fragrans) is a native of Bourbon; its leaves, known as Bourbon Tea, taste of Bitter Almonds, and smell like Tonquin Beans they are used to stimulate digestion, and in pulmonary consumption. Salep, which is imported from Asia Minor and Persia, is produced by the tubers of several species of Orchis, which are equally natives of Europe (O. mascula, Morio, militaris, maculata, &c.). Salep contains, in a small volume, an abundance of nutritive starch, associated with a peculiar gum, analogous to Bassorine; it was formerly considered a powerful analeptic; it is now used as a sweet, scented jelly, or mixed with chocolate. The root of Helleborine (Epipactis latifolia) is employed for arthritic pains; those of Himantoglossum hircinum, Spiranthes autumnalis, and Platanthera bifolia, are reputed to be aphrodisiac. The flowers of Gymnadenia conopsea are administered for dysentery; and, in North America, the tubers of Arethusa bulbosa are used to stimulate indolent tumours, and in toothache. The root of Spiranthes diuretica is renowned in Chili. The rhizome of Cypripedium pubescens replaces the Valerian as an antispasmodic, in the estimation of the Anglo-Americans" (Decaisne and Le Maout).
ORCHID FERTILISATION. The great source of information on this, as on so many other important and interesting questions in Natural Science, is to be found in the writings of Charles Darwin, who has written, upon this subject, the well-known work "On the Various Contrivances by which British and Foreign Orchids are Fertilised by Insects." This book must always be referred to by those who wish to understand the very curious structures that adapt many Orchids, in a very peculiar degree, to benefit by the visits of insects, while a smaller number are adapted for self-fertilisation alone. Not a little information is contained also in the works of Dr. Hermann Muller (of the chief of which a translation has been published, entitled "The Fertilisation of Flowers"), of Professor Asa Gray, of Delpino, and of many others, whom it is impossible here even to enumerate.
An endeavour will be made here to bring together some of the more interesting results arrived at by the various writers, selecting a few of the more characteristic examples from the species native in Britain, and thereafter giving a short account of some exotic species that exhibit peculiarities not met with in British Orchids. The flowers of Orchids in general are very curious in form and arrangements of their parts. This is well seen in the many figures of Orchids that have appeared in this dictionary (see Aceras, Aerides, Calanthe, Cattleya, Chysis, Coelogyne, Cymbidium, Cypripedium, Dendrobium, Epidendrum, Masdevallia, Maxillaria, and Miltonia).
But, despite this diversity, it is never difficult to recognise, that each flower is supported on a stalk, twisted half round, and that, when cut across, there are very many ovules visible in the stalk, and that this part really encloses the ovary, which is, therefore, inferior, and consists of three carpels, joined usually along their edges only. The flowers show six parts externally, viz., three sepals, much alike, and three petals, of which the lower one, in the mature flower, is almost always larger, broader, and more handsomely coloured than the others, and is called the labellum. It is often peculiar in form also, and very frequently it ends in a spur, which projects backwards, as the nectary. This latter, frequently, does not exude nectar into the tube, but contains it in the thin cells lining the latter; the walls of these cells are so thin as to allow insects (even moths) to pierce them readily, so as to obtain the juice. The tube is often nearly absent, but it is often of great length, and permits the honey to be secured only by insects with long probosces (such as some moths and butterflies possess), or by boring holes from without, as humble bees often do. This latter method, of course, does not benefit the flower at all. The essential, or reproductive, organs in the flower, consist of the stigmas and the fertile stamen, or, in Cypripedieae, the two fertile stamens, and the remains of two stamens, or of one stamen reduced to the state of a staminode, i.e., of a stamen no longer of use in forming pollen, but modified to perform some other function for the welfare of the plant. The relation of the larger parts of the flower to one another, will be more easily understood from the accompanying woodcut of the flower of Laelia albida. The sepals are the three narrower parts, situated behind, and overlapped by, the three petals, of which the lower in the figure is the labellum or lip. The dark, central spot is the opening of the nectary; and the upper part of the spot, is the situation of the stigmas. In Orchids, only two of the three are developed as stigmas, and often--in fact, usually--they unite. Just above the dark spot is seen the column, united to the labellum by two ridges. This column is regarded as formed by the fusion into one body of the upper part of the carpels, the fertile stamens, whether one or (in Cypripedium) two, and probably three or (in Cypripedium) two undeveloped stamens; but of the latter, as a rule, no clear trace remains. At the tip of the column is a body--the rostellum--usually regarded as the third stigma become useless as a stigma, but of great importance in securing the conveyance of pollen from one flower to the stigma of another. The labellum is also believed to be of compound nature, and to be formed of two metamorphosed stamens, and the median petal, closely united in growth. The structure of the fertile stamen, and the process by which pollen is conveyed from it to the stigma of another flower, by insect aid, in a common British Orchid will next be described, selecting, as a widespread and easily-obtained plant, the Spotted Orchis (Orchis maculata). In this species, the perfect stamen is situated on the front of the column; and in the anther there are two pouches, in which the pollen grains are inclosed. The grains are joined together into small masses, and these, again, are joined to form a single mass (pollinium) in each chamber. Each pollinium is formed like a club, supported on a slender stalk (caudicle), which ends below in a round, sticky ball. The two balls lie almost side by side, and are covered by an elastic membrane formed by the rostellum. This membrane prevents the disks from drying, which would render them useless. It is at first continuous over the disks, but it soon tears across, and, on being touched, it is easily dragged down, leaving them bare.
When a suitable insect (e.g., a moth) visits the flowers, and conveys the pollen of one flower to the stigmas of the next one visited, it pushes the proboscis down the tube of the labellum, and, in doing so, its proboscis, or its head, rubs against the membrane, and, depressing it, lays bare the sticky disks of the pollinia. These, as soon as they are touched, adhere to the part with which they are in contact, and, on the insect withdrawing its head, one or both of the pollinia are also withdrawn. They are erect when first withdrawn, but, in about half a minute, as the disks dry, the pollinia bend forward, and thus come to lie nearly alongside the proboscis, or other body, in the very best position to bring them into contact with the stigmas of flowers visited later. Owing to the little interval that elapses before the pollinium is in the suitable position, the insect has usually visited all the flowers on a stem before any of the pollen could be left in flowers of the plant from which it was taken; hence, cross-fertilisation between different plants is favoured. When a pollinium touches a stigma, some of the small masses adhere, and are dragged off, and thus one pollinium suffices for several stigmas. Insects have frequently been taken bearing pollinia, and often several pollinia are found adhering to the proboscis and head of an insect.
O. maculata, like most of this family, remains barren if insects are prevented from visiting the flowers, and aid in transferring the pollen is not given. There is no means in this plant of conveying pollen to the stigma, without extraneous help, and the adaptations for cross-fertilisation are complete. It may, therefore, be regarded as the type of a large section of Orchids, in so far as concerns its entire dependence on extraneous aid, though, in minor points, there is a considerable diversity in the methods of favouring cross-fertilisation; e.g., in O. pyramidalis, the sticky disks are united into a concave band, which adheres to the proboscis of the insect visitors. The pollinia pass through the same change of position as in O. maculata. Listera ovata, the "Twayblade," which is an inconspicuous, greenish Orchid, growing in grassy places, has the pollen masses lying immediately above the rostellum. The pollen masses are dry, and, therefore, cannot adhere of themselves to insects; but when the tip of the rostellum is touched, even very gently, by the insect, a drop of sticky fluid oozes out, and fixes the pollen grains in the suitable position to reach the stigmas of the next plant visited. The long, narrow, spurless labellum, secretes honey into a groove down the middle of the upper surface. The insect follows up this guide as it climbs up the labellum, and, on reaching the upper end of the groove, it is almost certain to touch the rostellum, and to have the pollen-masses affixed to its head. For a little the rostellum sinks, and closes the way to the stigmas; but soon it rises, leaving free access to the stigmas for later visitors to the flower. These visitors are attracted by a new supply of nectar in the groove. They are almost all small insects, with the proboscis short or absent, the nectar lying open. The genus Cypripedium--represented by C. Calceolus, the "Lady's Slipper", a scarce species in England, and by many tropical species, e.g., C. spectabile--belongs to a group that possess two fertile stamens, situated at each side, on the lower surface, of a broad, shield-like plate (the representative of the single fertile stamen in other Orchids). This plate overhangs the stigmatic surface, which lies on a prominent overhanging rostellum immediately below the plate. The labellum is much like the front half of a slipper. It forms a chamber, open above, and large enough to allow small bees to enter. This they do readily, to gnaw the hairs that line the middle of the floor. The lips on each side are incurved, so that, when an insect wishes to escape by the opening, it cannot crawl out as it entered; nor is there room for it to fly out. But, at the stalk of the labellum, a small opening is left on each side, where, if strong enough, by squeezing between the labellum and the stigma, and then between the labellum and either stamen, the prisoner can escape, carrying away one of the pollinia. As the stigma is touched before the anther, the flower cannot be fertilised with its own pollen, but only with that from one previously visited. Few flowers are formed on each plant.
Among exotic Orchids, the adaptations for fertilisation by pollen from other flowers are far more curious and striking even than the above, and the peculiarities in form and structure of the rostellum, the pollinia, and other parts of the flower, are often very strange, and cause them to resemble insects (e.g., in the Fly Orchis), or a minute dove, or other objects too numerous to describe, or even to mention.
Mr. Darwin has described fully some of the more remarkable, among which is the extremely curious genus Catasetum. In this genus of Orchids, the flowers are of different sexes, and they are so unlike that on C. tridentatum three supposed genera were based; the characters being drawn from the form of the flowers. These were Catasetum, based on the male; Myanthus, on the hermaphrodite; and Monachanthus, on the female flowers. The occasional presence of these flowers on the same plants has enabled botanists to understand their mutual relations. Cross-fertilisation must be effected before seeds can be formed; and this requires insect agency. In Catasetum (the male flower), the labellum rises up at the back of the flower (the ovary not making the usual half-twist), and is shaped like a monk's cowl. It contains no exuded nectar, but bees and other insects gnaw the inner surface greedily. The central column projects forward below the labellum, and bears the anther on its upper surface, the pollinia and disk being embedded in the tissues till set free by the mechanism now to be described. From each side of the rostellum grows a long, slender, curved horn, or "antenna"; and both lie within the hollow of the labellum. The right antenna occupies the bottom of the space, with its tip just projecting beyond the left margin; the left one curves upwards along the back of the labellum.
The slightest touch on either antenna immediately transmits some stimulus to the membrane over the disk of the pollinia, causing it to be rent; the disk springs out, by sudden removal of tension from the bent caudicle, and the whole mass is thrown forward, with the sticky disk in front, against the insect, if the antenna has been touched by an insect, and at once adheres in the position most likely to secure conveyance to the stigma of the female flower. The pollinia are not sensitive to contact of insects with any part of the flower except the antennae; but the position of these organs renders this contact almost certain to occur when the labellum is being gnawed. The female flowers of this species (formerly called Monachanthus viridis), resemble the male flowers in the position and general form of the labellum, which differs only in minor details. The column also agrees in position, but is smaller; the pollinia are rudimentary; the disk does not cohere with the pollinia, but soon falls away; and the antennae are absent. On the other hand, the stigmas and the ovaries are developed, and the seeds ripen abundantly. The form called Myanthus barbatus is very different in appearance from the other two, and Darwin points out that it comes near, in its structure, to the flowers of Catasetum callosum and of C. saccatum, but that it is hermaphrodite, though not known to seed. He suggests that it may be a reversion to the ancestral form. Owing to a bend in the ovary, the column and the long fringed labellum have reversed the positions they occupy in the other forms In the large group of Epidendreae.of which so many are cultivated in hot-houses, the adaptations for cross-fertilisation, though less complex than in Catasetum, well deserve a short notice. Cattleya is selected as an easily-obtained type; but Laelia, Chysis, and other genera, only differ from Cattleya in minor details. The positions of the labellum and of the column will be readily made out. The column is prominent, and arches forward, having the stigmas on the front or lower surface, near the tip. Just beyond them is the rostellum, the lower surface of which is thickly covered with sticky liquid. Beyond this, again, on the tip, is the anther. The pollen grains are joined to form four chief masses, which end in caudicles, to which many separate small groups, each of four grains, are stuck. The caudicles have no disks; they lie so that their tips are on the dry, membranous, upper surface of the rostellum. The labellum usually has the sides folded up so as to nearly surround the column. The nectary is a narrow tube between the labellum and the base of the column in front. When an insect of suitable size comes to suck the nectar, it must push its way between the labellum and the front, or lower, surface of the column; and must get well in below the latter before reaching the nectar. In doing this, its back presses against the stigmas, and leaves on them pollen from any previously visited flower. In retreating, the insect presses its back against the lower surface of the rostellum, and becomes smeared with the fluid, some of which is also forced on to the caudicles, and causes them to stick to the insect; and the pollinia are thus drawn out and fixed to it, to be transferred to the next flower visited. It will be observed that the method of affixing the pollinia in these plants reminds us a little of that previously described as occurring in Listera ovata; but the larger size renders it more easy to study the process in Cattleya and its allies, and the differences in details are sufficiently obvious. Some Orchids are now so specialised to adapt themselves for cross-fertilisation alone, that the stigma dies (as if poisoned) when pollen from the same flower is placed on it; e.g., species of Burlingtonia and of Oncidium. Between this extreme and habitual self-fertilisation in cleistogamic flowers, every stage is to be encountered. In many cases, where mechanical obstacles prevent the pollen of a flower being transferred to its stigma, the ovules are well fertilised (e.g., in Orchis maculata) if pollen is placed on the stigma of the same flower.
An interesting example of the way in which an Orchid, possessed of structures intelligible in their origin only as suited to cross-fertilisation, is converted by a slight alteration, so as to enable its ovules to be fertilised by pollen of the same flower, is well seen in the Bee Orchis (Ophrys apifera). In this plant, the parts are, in many respects, similar to those of Orchis maculata; but the pollinia have long, slender, flexible stalks, and the mass of grains in each slips out of the pouch of membrane, and hangs in front of the stigma, retained by the disk, and the slightest swaying movement causes it to strike against the stigma, and to leave pollen on it. The flower is not much, if at all, visited by insects, and it possesses no attractions for them. A striking anomaly is that observed by Dr. F. Muller, in South Brazil, in which an Epidendrum possessed two lateral stamens that secured self-fertilisation, and a median one, from which the pollen could be removed only by insect or other extraneous aid. The rarity with which this is effected, is indicated by the absence of attractions for insects in the flower. A considerable number of self-fertilised Orchids have been put on record. One of the latest papers on this subject is entitled, "On the Contrivances for Insuring Self-Fertilisation in some Tropical Orchids," by Henry O. Forbes, in the "Journal of the Linnean Society," vol. xxi., pp. 538-49, tt. 16 & 17.
ORCHID HOUSE. This term is applied to any garden structure in which Orchids are cultivated, to the exclusion of all, or nearly all, plants of another description. It is not necessary, nor, indeed, always thought advisable, to relegate these plants to certain houses by themselves; but in nurseries, where space for thousands of living imported specimens have frequently to be found, and a large collection of established plants is also grown, not only are special Orchid Houses found necessary, but large structures are frequently devoted wholly to the accommodation of such genera as Cattleya or Odontoglossum alone. Nor is this system entirely limited to nurseries; many private collections have now become so extensive, in consequence of the frequent additions made, that similar arrangements are being adopted. Where large and varied collections of Orchids are grown, they are usually arranged, according to the amount of heat required, in three separate houses, or three compartments of one house having the heating arrangements fully under command. When only a mixed collection is grown, the several genera forming it must be afforded positions as favourable to their well-being as circumstances admit, and the temperature varied somewhat by giving a greater or less amount of ventilation in different parts of the house in which they are placed. The following are the names usually given to the three different Orchid Houses, or divisions referred to. Approximate temperatures for each, during summer and winter, are also subjoined, as a general guide for cultivators, and not with the intention of their being rigidly followed: 1. East Indian House. To this department are relegated all Orchids requiring the highest temperatures, such as those originally received from the Eastern, and also from the hottest parts of the Western, hemispheres. These plants need plenty of moisture in the air during their season of growth, and also a circulation of air, somewhat cautiously applied, to avoid sudden changes of atmosphere. Temperatures: Summer--day, 75deg. to 90deg., with sun; night, 70deg. to 75deg. Winter--day, 70deg. to 75deg.; night, 60deg. to 65deg. 2. Brazilian and Mexican House. This provides accommodation for Orchids which require an intermediate temperature, as, for instance, the bulk of the Mexican species and a number from Brazil, &c. These will succeed in a drier atmosphere, generally, than those already referred to, but shrivelling must not be allowed. Temperatures: Summer--day, 75deg. to 85deg., with sun; night, 65deg. to 70deg. Winter--day, 65deg. to 70deg.; night, 60deg. 3. Peruvian House. A division specially for cool Orchids, natives of the mountains of South America, India, &c., many of which never appear to have any fixed season of rest. They are best suited with a cool temperature, and a more or less genial, most atmosphere all the year round. Temperatures: Summer--day, 60deg. to 70deg.; night, about 60deg. Winter--day, 50deg. to 60deg; night, 40deg. to 50deg., according to temperature outside.
The shape of structure most suitable for Orchid culture, generally, is a span-roof, or something very closely approaching it, such as a three-quarter span. Lean-to houses, with northern aspect, are well adapted for all the cool species and varieties of such genera as Masdevallia and Odontoglossum, in summer particularly, as these do not succeed in a high temperature, nor in houses where, from sun heat or other causes, the atmosphere is dry at any time of year. Where the ventilation is properly arranged and managed, cool Orchids may be grown as successfully in a structure of another shape as in a lean-to. A span-roofed Orchid House, about 60ft. long, 12ft. wide, and 8ft. high, would accommodate a large quantity of small plants, which could all be arranged on side stages, near the glass, or a large number might be suspended from the roof. The side walls should be carried about 4ft. or 4 1/2ft. above the ground, and small doors or sliding ventilators inserted in them, about half-way up. The top ventilation should be effected by having a longitudinal flap, made to rise up from the inside, or by small sashes attached with hinges to the ridge, and arranged so as to open without admitting rain in wet weather. Running sashes on the roof, and side-sashes opening on a level with plants on the stages, should now be recognised as things of the past when new Orchid Houses are being constructed. If plants requiring various temperatures are to be grown in one house, a glass partition will be the most convenient way of dividing one part from the other, which might have more or less heat and air applied, as found necessary. The dimensions given above would only be suitable for a house in which small or moderate-sized plants were intended to be grown; for specimens of considerable growth, or for large collections, proportionate measurements to any extent might readily be taken to meet requirements. Side stages should be about 4ft. from the ground. A system of having a double staging is sometimes adopted with excellent results for Orchids, namely, a bed of ashes, shingle, coke, or breeze, is laid on slates, which are supported by upright iron pillars. This bed is continually kept moist, and an open woodwork staging is placed above, on which the plants are stood. In some of the best-arranged Orchid Houses, the plants stand over a water-tank, formed beneath the woodwork staging. Into this the rain-water from the roof is conducted, and is always close at hand for watering the plants. It is most important that only rain-water be used for this last-named purpose, if it can possibly be obtained. Orchid Houses should never be built so high that the plants, when arranged inside, will be very far from the glass, or situated so as not to receive a sufficiency of light, which the majority of them require. There are few Orchids, except, perhaps, the Mexican species, that are not benefited by shading in summer. This should not, however, be thick, neither should it be permanently fixed on the roof. A thin shading, sufficient to exclude bright sunshine, while, at the same time, admitting light, is best; it should be tacked on rollers, and kept up during dull weather. General Remarks on Culture, &c. The special cultural requirements of all the important genera of Orchids being given elsewhere in this work, under their respective headings, it will be unnecessary to add more here than a few brief remarks of a general character. At one time, Orchids were limited to the gardens of a comparatively few wealthy owners, who took an especial interest in them, and spared no expense in obtaining such plants. The same conditions exist up till the present, in respect of rare specimens, or those of exceptional merit; but some representatives of the more popular genera are, fortunately, now found almost everywhere. This is mainly the result of enterprise, shown by sending collectors of plants to remote foreign lands, where Orchids abound, for the purpose of seeking new additions to the species, or varieties, already obtained, and for transmitting, in quantity, well-known and popular kinds, for distribution in this country. The method of culture, too, has been much modified, since it was found that the plants, in general, did not really require so much heat as what was, at first, thought necessary. Orchids are able (especially many of the strong-growing species) to withstand a considerable amount of ill-usage, compared with many other plants; otherwise, so many thousands would never reach this country and re-establish themselves in the way they do. Heat and moisture afford nearly all the plants need, consequently, the proper method of applying these is, at least, one of the main points in successful culture. Good fibrous peat, living sphagnum, and charcoal, form the principal materials necessary for the majority of Orchids. These are of more use for holding the plants in position, and retaining moisture for the encouragement of the tender roots, than for any particular nourishment afforded. It is remarkable how some attach themselves to a block of wood and succeed admirably with nothing else, save a little sphagnum and the proper attention in watering. Pots for Orchids should, with few exceptions, be quite half-filled with clean drainage, and they should be used as small as possible, in proportion to the size of plant. Shallow pans, made in various sizes, either for suspending from the roof or for standing on stages, have been used very extensively of late, with most excellent results. Orchid baskets should be made of teak wood, as it is hard, and lasts a long time. They may be purchased in several sizes, ready for use. Blocks, or rafts, may also be made of teak, or pieces of tree-fern will frequently answer equally well. A moist atmosphere is most desirable for all during the summer, or growing season, and, as a rule, plenty of water at the root. The amount of rest necessary varies considerably, and can only be properly apportioned by experience with different genera or species; some (as already remarked) are seldom completely at rest. Heavy syringing is not recommended at any season: a very slight dewing over the plants may be advantageous in summer; but, further than this, the use of a syringe should be limited to distributing water amongst the pots for moistening the atmosphere. Cleanliness amongst Orchids, in every respect, is one of the main roads to success. Dirt on the plants, or the pots, in the drainage, or even on the beds beneath, will soon produce an evil effect on the healthy appearance that should, and generally does, characterise Orchids receiving proper attention.
Insects, &c. Orchids are subject to many insect pests, and to a much-dreaded disease called the "spot." This latter is considered to be encouraged, especially in winter, by a superabundance of moisture and by a stagnant atmosphere. White and Brown Scale, Mealy Bug, Yellow and Black Thrips, Red Spider, Yellow and Green Fly, are all included in the insect pests to the attacks of which the plants are at times liable. Sponging with weak soft soap or tobacco water is recommended for eradicating any of them: fumigating Orchids is a practice not to be approved of, as it undoubtedly causes injury at times. Cockroaches, Slugs, and Snails, must also be included amongst the enemies of Orchids.
ORCHIS (the ancient name, from orchis, testiculus; referring to the two oblong tuberous roots of some of the species). Including Anacamptis, Barlia, and Himantoglossum. ORD. Orchideoe. A large genus (nearly eighty species) of hardy terrestrial orchids, natives of Europe, temperate Asia, and North Africa, with two North American, and two in the Mascarene Islands. Many of them are interesting and curious rather than showy. Flowers in dense or loose, sessile spikes, or in very short, pedicellate racemes; sepals and petals nearly equal; lip three (rarely four or five) lobed, larger than the petals, hanging down anteriorly between the lower segments of the calyx, and extended in the form of a spur; anther confluent with the column, cells two, diverging at the base; pollenglands in a common pouch. Stem erect, herbaceous, leafy at the base. The few species worth cultivating thrive best in a deep rich soil; those which naturally prefer chalky soils should be planted in one of similar nature. They are very impatient of disturbance at the roots. Propagated by division. Transplanting should only be performed during the autumn months, when the growth of the young roots will have fully matured.
O. foliosa (leafy).* fl. purple, numerously disposed in an ovate or oblong-ovate spike, about 9in. long and 3in. broad; sepals erect, ovate, blunt; petals similar in form, but narrower and smaller; lip pendent, very broad, three-lobed, much longer than the spur. May. l. unspotted oblong, lower ones blunt. h. 1 1/2ft. to 2 1/2ft. Madeira. A very desirable plant, varying a little in size of inflorescence and colour of flowers. (B. M. 5074; B. R. 1701.) O. fusca (brownish). A synonym of O. purpurea.
O. hircina (goat-scented). Lizard Orchis. fl. dirty greenish-white, with a disagreeable smell, large, remarkable for their long, linear lip; sepals converging over the column; petals small; spike dense, 4in. to 8in. long. Summer. h. 1ft. to 2ft. Europe (Britain, East Suffolk and Kent; almost extinct), North Africa. (Sy. En. B. 1448.) O. h. romana (Roman). In this variety, the lip is rosy-purple. Rome, 1871. O. lactea (milky). fl. purple; sepals very acuminate; lip threeparted, very glabrous, equalling the incurved spur. May. l. oval, acute, cuspidate. Barbary, 1815. (B. M. 1932.) O. latifolia (broad-leaved).* Marsh Orchis. fl. purple or red; lip convex, crenate, slightly three-cleft; spur conical; spike dense, many-flowered. June. l. lanceolate, broadest near the middle, usually spotted with purplish-black. Stem about 1ft. high. Europe (Britain), Asia. (F. D. ii. 266; Sy. En. B. 1458.) O. l. lagotis (hare's-eared). A variety having purple flowers, with darker bands on the lip. Alps of Piedmont, 1869.
O. laxiflora (loose-flowered). fl. bright crimson-purple, in a very loose spike, 3in. to 10in. long. Summer. l. lanceolate or linear-lanceolate, 3in. to 6in. long, not in a rosette. h. 1ft. to 3ft. Europe (Guernsey and Jersey, in wet meadows), 1820. (Sy. En. B. 1456.) O. longibracteata (long-bracted). fl. purple; sepals very obtuse; lip fleshy, crisped at base, four times as long as the thick, conical spur; laciniae obtuse, crenate; bracts exceeding the flowers; spike long, many-flowered. May. l. oblong, narrowed at base. Sicily, 1818. (B. R. 357.) O. longicornu (long-horned). fl. purple, disposed in dense spikes, 6in. to 8in. long; lip striped with lilac. May. h. 12in. to 20in. North Africa, 1815. A very handsome species. (B. M. 1944; B. R. 202; S. B. F. G. 249.) O. longicruris (long-shanked). fl. pale purple, in a thick, subcorymbose spike; sepals acuminate; lip thrice as long as the incurved spur; laciniae all linear, acuminate. May. l. oblonglanceolate, undulated, obtuse. Europe. (S. F. G. 927; B. R. 375, under name of O. tephrosanthos undulatifolia.) O. maculata (spotted).* fl. pale purplish or whitish, variously spotted with purplish-brown, and disposed in an ovate spike; lip flat, crenate, three-lobed; spur cylindrical, shorter than the germen. June. l. lanceolate, spotted with purplish-brown. Stem 1ft. high, slender. Europe (Britain), Asia. (F. D. vi. 933; Sy. En. B. 1459.) O. mascula (male). fl. rich purple, disposed in a rather loose spike; the two lateral sepals reflexed upwards; lip four-lobed, crenate, having the disk white and spotted. Spring. l. chiefly radical, elliptical or lanceolate, usually spotted with black. Europe (Britain), North Africa, and West Siberia. (F. D. iii. 457; Sy. En. B. 1455.) O. militaris. Military Orchis. fl. numerous, in a dense, oblong spike; sepals usually purple, converging over the petals and column in the shape of a helmet; lip longer, paler, more or less spotted with purple, four-lobed; spur not half the length of the ovary. Spring. l., lower ones broadly oval to oblong. Tubers entire. h. 1ft. to 2ft. Southern England. (F. D. viii. 1277; S. B. F. G. 163; Sy. En. B. 1452.) O. Morio (buffoon). fl. six to eight, in a loose spike; sepals purplish, arching over the smaller petals and column in the form of a helmet; lip pinkish-purple, pale purple in the middle, with darker spots; spur obtuse, nearly as long as the ovary. Early summer. l. few, almost radical, and two or three sheathing scales higher up the stem. h. 6in. to 8in. Europe (Britain), West Asia. (F. D. ii. 253; Sy. En. B. 1454.) O. pallens (pale). fl. pale yellow; sepals ovate, obtuse; lip round, with three entire lobes; spur twice as long as the lip; spike dense, oblong. May. l. obovate-oblong, very obtuse. h. 9in. Europe, 1825 (B. M. 2569, under name of O. sulphurea; J. F. A. 45.) O. papilionacea (butterfly). fl. purple; sepals oblong, acute; lip crenulate, unguiculate, equalling the conical, incurved, pendulous spur. April. l. linear-lanceolate, acute, closely sheathed. h. 1 1/2ft. Rome, 1788. SYN. O. rubra. (B. R. 1155, and S. F. G. 928.) O. pauciflora (few-flowered). fl. yellow, spicate; lip darker, and sometimes spotted. l. linear-lanceolate. Italy, &c., 1844. (R. G. 1149, Fig. 2.) O. purpurea (purple).* fl. 3/4in. across; sepals and petals green and purple outside, paler inside, spotted; lip pale rose, spotted with purple; spikes usually large, many-flowered. May. l. oblong-obtuse, 3in. to 5in. long. Britain. SYN. O. fusca.
O. pyramidalis (pyramidal). fl. rich rose or purplish-red, remarkable for their slender spur, longer than the ovary; sepals lanceolate, spreading; petals converging over the column; lip broad, three-lobed; spike dense, 2in. to 4in. long. Summer. l. lanceolate, usually narrow, and pointed. Stem 1ft. or more high. Tubers pointed. Europe (Britain), North Africa. SYN. Anacamptis pyramidalis. (F. D. xii. 2113; J. F. A. 266; Sy. En. B. 1449.) O. rubra (red). A synonym of O. papilionacea.
O. sambucina (Elder-scented). fl. yellow or purple, in a dense oblong spike; sepals slightly obtuse; lip obsoletely trilobed; spur pendulous, inflated, twice as long as the lip. April. l. ovate-oblong, very obtuse. h. 9in. Europe, 1825. (J. F. A. 108; S. B. F. G. 199, under name of O. Schleicheri.) O. Schleicheri (Schleicher's). A synonym of O. sambucina. O. spectabilis (showy). fl. few, on a four-angled scape; sepals and petals all lightly united to form the vaulted galea, or upper lip, pink-purple; the ovate, undivided lip white. May. l. two, oblong-obovate, shining. h. 4in. to 7in. United States, 1801. (L. B. C. 78.) O. sulphurea (sulphur). A synonym of O. pallens.
O. tephrosanthos (ash-colour-flowered). fl. purple, variegated, in a thick, cylindrical spike; sepals acuminate; lip twice as long as the incurved spur; laciniae linear. April. l. oblong-lanceolate, slightly acute. (B. M. 3426.) O. tridentata (three-toothed). fl. pale purple, in a corymbose spike; sepals very acuminate; lip equal to the spur; laciniae denticulate. May. l. oblong-lanceolate, acute. h. 9in. South Europe, 1818. (B. R. 367.) O. ustulata (scorched). fl. in a dense spike, the deep purple of the unexpanded ones imparting a burnt, or scorched, appearance; sepals deep purple, pointed, converging over the column and the small, narrow petals; lip white, purple-spotted, four-lobed; spur very short; spike 1in. to 2in. long. Spring or early summer. l. few, oblong or lanceolate. Tubers entire. h. 6in. to 8in. Europe (Britain), West Siberia. (Sy. En. B. 1450.) OREODOXA (from oreos, a mountain, and doxa, glory; referring to the lofty stature of some of the species). ORD. Palmeae. A small genus (five species have been described) of elegant, unarmed, stove, tropical American palms, with slender, ringed stems, bearing large, terminal leaves, with long, sheathing stalks, forming a cylinder around the summit. Flowers white, small, monoecious, the spikes inclosed in double, somewhat woody spathes. Fruit ovoid or oblong-ovoid. Leaves equally pinnatisect; segments narrow, linear-lanceolate, narrowed at apex, unequally bifid, pinnate. The species thrive best in a compost of loam, with a little peat and sand. They are admirably adapted for growing in subtropical gardens, where some shelter from winds will be needed, and also for decorating apartments. For general culture, see Phoenix.
O. granatensis (New Grenadan). l. pinnate, with long, narrow segments, which are more or less drooping. Stem smooth. Columbia, 1879. An elegant species, admirably adapted, when in a young state, for table decoration. O. oleracea. Cabbage Palm. l. pinnate, 4ft. to 6ft. long, grace-fully arched; segments 1ft. to 2ft. long, bright dark green. Stem slender, swollen at the base, freckled with blackish-brown. h. 100ft. West Indies, 1844. O. regia (royal).* l. pinnate, 3ft. to 6ft. long, the segments 6in. to 12in. in length, and nearly 1in. broad, bright green. Cuba, 1836. A very graceful, slender-growing species.
O. Sancona (Sancona). An easily cultivated and handsome species, with the leafstalks a reddish-bronze when young. It is used, on the Continent, like Cocos and Chamaedoreas, for the decoration of apartments. Tropical America. O. ventricosa (ventricose). A synonym of Gaussia Ghiesbreghtii. OREOPANAX (from oreos, a mountain, and Panax; alluding to the relationship of the plants to Panax, and their natural habitats). ORD. Araliaceae. A genus of glabrous or tomentose, stove shrubs or trees, allied to Hedera. Sixty-four species have been enumerated, but this number may be reduced; they are natives of tropical America, mostly in the region of the Andes. Flowers capitate, racemose, or paniculate, sessile, each provided with two or three bracts; stamens equal in number to the valvate petals; ovary three to five (rarely six or seven) celled, surrounded by as many styles. Leaves entire, palmately lobed or digitately compound; lobes or leaflets entire or argutely toothed. All the species thrive in good loam, and require abundance of water during the summer months. During the dull winter season, when the plants are at rest, but little water will be needed. Propagated by cuttings of the young shoots. The species here described are probably the only ones yet introduced. O. Andreanum (Andre's). fl. in globular heads, arranged in a terminal, erect raceme. l. petiolate, elliptic, entire, or roundish or sub-cordiform and sub-trilobed, or palmate with pinnatifid lobes, covered beneath, as well as the petioles and branches, with a reddish, deciduous tomentum. Trunk simple or slightly branched. Andes of Ecuador, 1883. A very ornamental shrub. O. dactylifolium (finger-leaved). l. palmate, usually sevenlobed; lobes deeply divided, and measuring from 6in. to 18in. in diameter; under side clothed with rusty tomentum, upper smooth and deep green. Mexico. An elegant, erect-growing shrub.
O. Epremesnilianum (Count Epremesnil's). l. large, digitate, long-petioled; leaflets seven to nine, the two outer ones oblong, entire, and narrowed at both ends, and the middle ones pinnatifid. 1883. This is probably only a variety of O. dactylifolium.
O. peltatum (peltate). fl. greenish-white, in globose heads, disposed in terminal panicles. l. long-stalked, coriaceous, five to seven-nerved, round-cordate or peltate-suborbicular, palmately three to five-lobed; lobes ovate-lanceolate, acuminate, remotely and repandly toothed. Mexico. (R. G. 1862, 363.) O. platanifolium (Plane-leaved). fl., petals white, tomentose externally; heads sub-globose; raceme paniculate. l. petiolate, coriaceous, glabrous and shining above, fuscescent-tomentose beneath, truncate and seven-nerved at base, seven-fid at apex; divisions oblong, acuminate, entire. Stem arboreous. Andes of Peru. SYNS. Aralia platanifolia, Hedera platanifolium. O. Thibautii (Thibaut's). fl. greenish, borne in numerous, globular, stalked heads, arranged on the side of an elongated axis. November. l. alternate, stalked, digitate; segments shortly stalked, lanceolate, glabrous. Mexico, 1862. Small tree. SYN. Aralia Thibautii. (B. M. 6340.) O. xalapense (Jalapa). fl. greenish; petals glabrous; heads sub-globose; racemes paniculate. April. l. long-stalked, digitate; leaflets five to seven, glabrous, shining above, dotted beneath, lanceolate-oblong, acute, narrowed at base, entire, sub-coriaceous. h. 6ft. Mexico, 1828. Shrub. SYNS. Aralia xalapensis and Hedera xalapensis.
ORGYIA ANTIQUA, or VAPOURER MOTH. This is one of the most widespread of injurious insects, and is common even within the limits of London. Its larvae are at times very hurtful to deciduous trees and shrubs of many kinds. The male moth is shown of the natural size in Fig. 774. The body is dark brown; the wings are rusty-brown, with markings of deeper and paler tints, and at the rear angle of each fore wing is a conspicuous white spot. The female has the wings reduced to tiny scale-like organs on each side of the heavy, clumsy body, which is covered with woolly, yellowish-grey pubescence. The larva is shown of the natural size in Fig. 775. It is covered with yellowish hairs. On the back of the fourth to seventh segments are long tufts of yellow or brown hairs; and on the back of the last segment, and on each side of the head, is a long black tuft of clubbed hairs. The larva may reach 2in. in length. When full fed, it spins, in crevices or among leaves, a slight greyish-brown cocoon of silk, largely mixed with its own hairs, and in this changes into a hairy pupa. The female emerges in autumn, and lays her eggs on her cocoon, where they pass the winter, the larvae emerging in spring. Remedy. The best remedy is hand-picking the insects in all stages of development; the larvae especially are conspicuous.