|Nepenthes subsp. var.||tropical pitcher plants or monkey cups|
|Standard Cyclopedia of Horticulture|
Nepenthes (from Greek for without, and care). Nepenthacae, the only genus of the family. The genus includes those forms that are popularly called Pitcher- Plants, and consists of about seventy species, all of which are found in the Orient. The generic name was given in allusion to the statement in the "Odyssey," where Helen so drugged the wine-cup that its contents freed men from care and grief. Linnaeus in naming the genus truly expressed the feeling that some travelers have since experienced when he said, "If this is not Helen's Nepenthes, it certainly will be for all botanists. What botanist would not be filled with admiration, if after a long journey he should find this wonderful plant? In his astonishment past ills would be forgotten when beholding this admirable work of the Creator."
All of the nepenthes are climbing or rarely upright plants of rather straggling habit and semi-woody consistence. In height they vary from a foot to 60 or 70 feet, while the stem varies from the thickness of a pencil to an inch across. In their native haunts the plants spread their rootage abundantly through the decaying humus of moist "scrub" land, and when planted in an open greenhouse border, they grow equally vigorously. But the roots always spread near the surface, and free oxygen exchange is necessary. Some of the more striking species, like N. Veitchii and N. Edwardsiana, are often or habitually epiphytic. The former has become so adapted to this mode of life that its stem creeps horizontally or obliquely upward along tree branches, while the leaves with their yellow-green pitchers spread in double rows on either side. Such forms, therefore, succeed only under cultivation when treated like the epiphytic orchids. Well-known species, like N. ampullaria and N. Rafflesiana, may form long rope-like stems amid the rather open forest vegetation of their native haunts, and then spread out amongst the tree crowns, there to bear the graceful pitchers and the racemes of nectariferous flowers. These latter, according to Burbidge, are often encircled by groups of insects.
Each fully developed leaf is of complicated structure. It may be either sessile or stalked, but always has a lower flattened blade portion, that is traversed lengthwise by two to ten or twelve veins, all of which are braced together in turn by transverse or oblique nerves. The number and disposition of the former yield valuable aid in classification of the species. The midrib is then prolonged as a tendril of varying length, but of great tenacity. This can wind around supports, and also helps the stem in bearing the crown of leaves, and supports the pitchers with their often considerable weight of water.
The pitcher is the greatly expanded and hollowed-out end of the midrib. It usually bears two fringed or ciliate wings in front, that in the seedling leaf are continuous with the blade below, and gradually become separated from it as older leaves are produced. They represent, therefore, lobes that are separated off from the blade portion in the early history of the leaves. The margin of each pitcher, except in N. Lowii (Fig. 2462), is widened or thickened without and within into a collar-like rim or peristome, that is striated, corrugated or even ridged from within outward, and is of shining aspect. The inner, or the outer, or both rim-margins may be curved downward and inward, so as to give a cylindric aspect to the peristome (Fig. 2463), or it may be widely expanded as a spreading collar (Fig. 2165). The pitchered or hollowed-out midrib ends in a small spur at the back of the peristome, and just behind the insertion of the lid that next deserves notice. This lid represents two terminal lobes of the leaf formed on either side of the spur, and which have grown forward, have fused, and so have caused the lid to be traversed by two main veins from which minor ones may branch off.
All of the above details would be comparatively unintelligible did we not refer shortly now to the numerous secreting glands that are formed over the leaf, and to the function of these in securing the capture and digestion of insects or other prey. Over the lower blade surface, here and there along the tendril, over the pitcher and lid exterior, but most abundantly over the inner lid surface, small spots can readily be detected that exude a honied juice. This is greedily licked by ants, cockroaches, and other—mostly running—insects. They are thus attracted to the edge of the peristome, or upward to the inner lid surface with its rich nectar supplies. In either case they usually step ultimately on the shining surface of the peristome. But the finely or coarsely serrated inner edge of this carries the openings of large sunken glands. These exude a juice that is greatly liked by insects. In attempting to reach the droplets they often slide off into the pitcher interior. This shows a different but equally noteworthy device. In some species, like the commonly grown N. ampullaria, N. Hookeriana and N. Chelsonii, the entire pitcher interior is smooth and glistening, but abundantly studded with small glands that excrete an acid peptonizing fluid, capable of converting albuminous substances like animal flesh or white of egg into a dissolved peptone or even into a simpler tryptophan product that can readily be absorbed and assimilated by the inner pitcher wall.
In most species and hybrids, however, now under cultivation, the upper one-third or one-half, of the pitcher interior is extremely smooth and bluish or purplish waxy in aspect. This forms a sliding or "conducting" surface, that ensures dropping of insects into the lower area, where digestive glands occur as already described. So following the nomenclature of Hooker and the writer, the general external leaf area with its scattered honey-glands forms the "alluring" surface. The inner lid area and the peristome rim with their concentrated honey-glands, form the "attractive" surface, the smooth upper part of the interior that is devoid of glands can well be named the "conducting" surface, while the glistening lower area with its abundant digestive glands, forms the "detentive" and digestive surface.
In greenhouses where ants and cockroaches occur, the captured prey soon accumulate in such pitchers as N. hybrida, N. Hookeriana or N. khasiana, at times also to such an extent that the ammoniacal fumes of the decaying contents cause a brown discoloring of the pitcher-wall. The loose stuffing, therefore, of the pitchers with wadding or moss has been recommended by some growers. But it appears certain that the pitchers are thereby prevented from securing, digesting, and absorbing animal prey that seems to aid in the nutrition of the plant under wild as under cultivated conditions.
Another feature deserves mention here from the cultural and physiological standpoints. The leaves bear an abundance of minute brown peltate hairs, that appear to the naked eye as dark specks. Even though nepenthes be almost wholly deprived for a time of their roots, the plants remain healthy if kept in a moist atmosphere. This and other evidence, that cannot here be cited, suggest that atmospheric moisture may be absorbed directly through the leaf surface, though such a view is contrary to current physiological opinion.
In contrast to the above relations, it has been shown by three observers that several species of insects and also a spider are capable of living, and even, in some cases, of breeding, in the pitcher liquid, while they are able with impunity to ascend and pass out from the pitcher cavity. Their ability to live in the pitcher liquid that digests other insects seems to be due to their having an antagonistic or neutralizing ferment to that in the pitchers.
The size, shape, and color-markings of the pitchers vary greatly. The pitchers of the rare N. bicalcarata are usually yellow-green, but may be of a faint brick red. Projecting downward from the top of its high neck and so overhanging the pitcher-cavity are two strong sharp spines. These have been considered by Burbidge to act as protective spines against the thieving habits of a small lemur (Tarsius spectrum) that attempts to rifle the pitchers of their insect prey. When it tries the above it is often caught by the nape of the neck, and tumbled into the pitcher. Equally curious in the same species is the thickened end of the tendril alongside the pitcher, that is always thickened, and in the wild state is drilled by ants which form a home or myrmicarium in the interior.
N. Lowii (Fig. 2462) has large leathery urnshaped pitchers of a greenish yellow hue, each strongly constricted in the middle, and so in outline resembling the finely colored N. ventricosa and N. Burkei, now in cultivation from the Philippines. N. Rajah, found about 6,000 feet, on Kinabalu only, attains a height of 5 to 6 feet, but its huge claret-crimson goblet pitchers sit in the moist moss of the ground at the ends of the large dependent leaves which spread out from the stout stem. N. vittosa and N. Edwardsiana are soil-growers or often epiphytes with brilliant crimson pitchers of striking aspect that grow on Kinabalu at 8,000 to 10,000 feet elevation. Two splendid new species, N_. Merrilliana and N. truncata, have recently been described from the Philippines, which suggests that these islands may yet yield other attractive types.
The flowers appear in panicled or simple racemes on the young wood, and each raceme is opposite a bract- leaf that differs usually in shape and venation from the other foliage-leaves. In greenhouses of the northeastern states, these inflorescences appear as a rule, from July to October, but only on plants or on shoots that have been allowed to grow long. Thus racemes appear on N. maxima (N. Curtisii), N. Hookeriana, and N. phyllamphora when the shoots are from 5 to 12 feet long. The plants are always dioecious, and so for production of seeds under cultivation a staminate and pistillate plant must be in bloom simultaneously. Failing this, it has been shown experimentally that pollen from a staminate plant can be kept good for days or even weeks, if preserved in tinfoil or in paraffin paper and in a cool place. Taplin adopted this method in order to secure some of his fine hybrids, while N. Dicksoniana (page 2128) was got in the Edinburgh Botanic Garden from the seed-parent N. Rafflesiana, by applying to it pollen of N. Veitchii forwarded from the Veitch establishment in London.
The staminate flowers are produced in dense paniculate cymes as in N. ampullaria, or in loose simple racemes as in N. gracilis and N. sanguinea. Each consists of four green, yellowish, red or claret-colored sepals, about 3/8 by ¼ inch in size on the average, and of rather thick texture. The inner surface is closely dotted over with honey-glands that resemble the attractive lid-glands, and which pour out an abundant nectar secretion at the time of blooming. This is often accompanied by a heavy somewhat fetid odor, and the two attractions draw small insects in great numbers to-the flowers. Becoming dusted with pollen they carry this to pistillate flowers on other plants. The stamens rarely may be from twenty to twelve in number, commonly they are from ten to eight, or they may be as few as four. The filaments are fused into a short pillar that bears the terminal anthers in a rounded crowded mass. When the latter dehisce the whole appears as a dusty ball of pollen.
The pistillate flowers bear sepals like those of the staminate. The pistil consists of four carpels that are united below to form a four-celled ovary. This incloses many minute elongated ovules, which after fertilization continue to lengthen, and swell up in the" middle to form the seeds. The style is either very short and thick, or is practically absent. The stigma is four-lobed to rounded, and forms an expanded thickened mass on top of the short style or of the ovary. It, as well as the sepals, persists during maturation of the fruit. The fruit when ripe is a dry glabrous and shining or a hairy capsule that dehisces loculicidally into four valves. The seeds vary in number, according to the species, from 100 to 500 in a capsule. Each is a light delicate elongated thread-like body, due to great elongation of the loose seed-coat on either end of the central mass. From their extreme lightness they can readily be blown to considerable distances, and this fact, along with the direction of the prevailing monsoon winds, seems to explain the distribution of the species along the western and northwestern sides of the foothills or the mountains where they mainly occur.
The literature of the group has been recently summarized by the writer in his monograph published as hft. 36 of Engler's "Pflanzenreich." A general description is there given in English on pp. 2-26, while detailed descriptions of the species and hybrids follow in Latin. An interesting account of the group is given by Veitch and Burbidge in Journ. Roy. Hort. Soc., vol. 21 for 1897, on pp. 226-262.
History and distribution.
We owe the first notice of the group to the French botanist Flacourt. In his "History of the Island of Madagascar" (1658) he described the only native pitcher-plant of that region as Anramitico, and inclined to regard the pitcher as a flower or hollow fruit. In 1679 Breyn described the only Ceylon species as Bandura Zingalensium, and he justly regarded it as a vegetable wonder. Since that time other forms have been discovered in the Seychelle Islands, in southern China, in northeast India, in the Philippines, the East Indian Islands and in northeast Australia. But the headquarters of the genus extend from the Malay Peninsula—where. are ten species— through Borneo and Sumatra, that contain about twenty-four species, to New Guinea and Australia in a southerly and the Philippines in a northerly direction, where are about twenty-six species.
While nearly one-fourth of the species grow in hot reeking swampy situations at or near sea-level in the eastern tropics, the larger number occur in moist ground on the western and northwestern sides of the mountains at elevations of 1,000 to even 10,000 feet. Thus the lone and impressive mountain, Kinabalu in northwestern Borneo, that rises to a height of 13,700 feet, overlooks a tropical shore region that is rich in nepenthes. But, from 3,000 to 10,000 feet, it harbors eight species, some of which are the largest and most gorgeously colored of the genus. The zone of the mountain where the finest are found extends from 6,000 to 10,000 feet and Burbidge has graphically described how this entire belt is almost continuously shrouded in a dense mist, due to moisture precipitation from meeting of the hot lower current of air with the cold currents from the mountain top. This moist dripping climate seems eminently to suit the forms found there, while all of the species flourish best when kept in moist "steamy" surroundings. Repeated attempts were made, from 1750 onward, to introduce and grow a few of the species from Madagascar, Ceylon, India and Borneo. But the type of greenhouse of this earlier period, and the method adopted in their cultivation combined to prevent success. From 1830 to 1860, however, so well had the mode of culture advanced, that seedlings were raised in the Edinburgh, London and Chatsworth gardens, while the Veitch firm that now had collectors like Lobb busy in the native haunts of the genus, imported living plants as well as seeds, both of which they grew successfully. A great impetus was given to the culture of the group when gardeners like Dominy, Taplin, Seden and Court succeeded in crossing some of the species then cultivated, from 1850 to 1870, and in raising hybrids there from. These hybrids seemed often to combine good points of both parents, while they, as well as many hybrids since secured, are usually more easy of cultivation, and form a greater showing of the striking pitchers than does either parent. But a new and very lively interest was created in the group after Hooker drew attention to the remarkable structure of the pitchers, and their adaptation to the catching and digestion of insect prey, as set forth in his Belfast address before the British Association in 1874. Collectors like Curtis, Burke, and Burbidge were commissioned by the Veitch firm to secure every available type encountered from Madagascar to Australia. Successful methods of raising, growing and flowering these had been devised; numerous new hybrids appeared in England, America and France from 1875 to 1900, while the scientific interest in the group that was stimulated by the writings of Darwin and Hooker has caused an ever-increasing demand for such plants in every typical collection.
Beginning from the top they are: N. villota, N. Lowii, N. Rajah, N. Hookeriana, and N. Rafflesiana. The first three belong to the famous Kinabalu group. The fourth is the parent of more hybrids than any other kind.
A description of the nepenthes would be very incomplete in such a work as the present, did we not refer again to the history of their hybridization by man, and the resulting production of hothouse types that more than rival in beauty many of the wild species, and which are, as already indicated, more easy of cultivation than are the parent forms.
When Dominy first attempted to cross Nepenthes, few fine forms were in cultivation, N. Rafflesiana and N. Hookeriana being the best. About 1858 or 1860 he crossed flowers of the former with pollen from what was probably N. gracilis from Borneo. The resulting hybrids that were sent out from the Veitch nurseries as N. Dominii were at once a success under cultivation, and stimulated further experiment with species of the group. Dominy, Seden, Court and Outram continued this in England from 1860 to 1880, while Taplin, a friend of the two latter, extended the work in Such's collection. By the latter period it had been proved that the species of Nepenthes can be hybridized and rehybridized, at the same time remaining fertile. The varied beauty and easy culture of the hybrids—specially those of Taplin, which were secured and distributed mainly by Williams of London, rendered the group more popular. An added stimulus was given when Court raised N. Mastersiana about 1880. But such striking species as N. Veitchii, N. Northiana, N. maxima, (N. Curtisii) and N. sanguinea were all soon to hand, and so hybridizers like Court, Tivey, Lindsay, and Gautier in Europe, as well as Oliver and Siebrecht in this country, produced novelties in which the "blood" of three to four species was blended. In France, Jarry-Desloges and his gardener have obtained some beautiful and complex hybrids, but they have not as yet been distributed. The pitchers of some of the above when well grown are magnificent, the plants are in no way more difficult of culture than many of the well-known orchids, while the climatic conditions of America, when modified by moist storehouse treatment, seem eminently to favor vigorous growth. They have therefore become familiar objects in many American greenhouse collections during the past decade.
All of the species now in cultivation hybridize readily with each other, and produce abundant as well as good seeds. These should be sown on the surface of a seed- pan that is filled with a finely chopped mixture of sphagnum, pot crocks and charcoal. A bell-jar should cover the pan, and it should then be set in a plate of water to ensure a steamy atmosphere. Germination occurs in two to four weeks. The seedlings should be potted off into thumbs when about a month old, and then changed every two months into larger pots. Well- grown year-old plants begin to show adult characters.
Nepenthes are increased by cuttings and by seeds. The ripened shoots, with four or five leaves attached, make the best cuttings. They may be rooted from December till the end of January, but under proper conditions the operation may be performed at any time during the year. Some of the free-rooting kinds, such as N. Dominii, N. gracilis. N. Phyllamphora and N. Mastersiana, may be rooted in sand under a glass with a little moss tied around the base of each cutting. Under this treatment the temperature of the sand should be about 80° F. When the roots show through the moss they should be put in small pots and kept close for a couple of weeks. The most satisfactory method of propagation is to put the base of each cutting through the hole of an inverted 2-inch rose pot, plunging the pot in sphagnum moss in a temperature from 80° to 90°. F. During the operation of rooting they must be kept in a close propagating-frame and frequently syringed. When the roots are about ¾ inch long the cuttings should be potted, using a mixture of finely chopped fibrous peat, moss and sand, with a little finely broken charcoal added. They should be replaced in the moss and kept close until the pots are fairly well filled with roots and then gradually hardened off. All of the kinds do best suspended from the roof of a hothouse, the temperature of which should not fall below 65° F. in winter. The plants may be grown either in orchid-pots or -baskets. In potting or basketing plants from 4-inch pots, large pieces of potsherd and charcoal should be firmly placed here and there among the potting material, which should consist of rough fibrous peat, moss and sand. The plants should not be allowed to grow as vines unless they are intended to produce seed. When large-sized pitchers are wanted, the ends of the shoots should be nipped out after several leaves have been made and the pitchers are in the process of development; this throws strength into the last-formed leaves and produces very large pitchers. When the plants are in active growth they should be well drenched with water at least once each day and syringed frequently, but care should be taken not to over water newly potted specimens. They should at all times be shaded from bright sunshine, and when a house is devoted to them, or partly occupied with plants requiring similar treatment, it should be shaded with cloth fixed to rollers. Well-pitchered plants may be taken from the growing house and exhibited in good presentation for a long time in a house under conditions which would be unfavorable for their growth. All of the hybrid forms are of easy culture. N. Mastersiana, N. Dominii, N. Outramiana and N. Henryana produce pitchers very freely. The species, as a rule, are not quite so free; but some of them thrive equally as well as the garden forms. N. Rajah, N. Northiana, N. sanguinea, N. albo-marginata and N. bicalcarata are all more or less difficult to manage, as the conditions under which they grow in their native haunts are sometimes not easily imitated. N. ampullaria, N. Rafflesiana, N. Phyllamphora, N. distillatoria and N. Kennedyana are usually seen well furnished with good pitchers.
N Alliottii-N. Northiana x N. maxima.—N. atropurpurea - N. sanguinea x N. maxima var. superba.—N. Boisiana-N. Tiveyi x N. Morganiae.—N. compacta-N. Hookeriana x N. Phyllamphora.—N. Courtii—N. (?)x N. Dominii. A hybrid of Court that is rare in cult. G. C. II. 16:845.—N Deslogei—H. Tiveyi x N. mixta.—N. excelsa- N. Veitchii x N. sanguinea.—N. Fournieri-N. Northiana x N. mixta.—N. Gamerii-N. Tiveyi x N. mixta.—N. Gautieri—N. Northiana x N. mixta.—N mixta-- N grandis-N. maxima var. superba x N. Northiana var. pulchra.—N Henryana—N. Sedenii x N. Hookeriana. I. H. 4:15; 29:460. G. W. 14:297.—,N longicaudata N. maxima var. superba x N. Northiana var. pulchra.—N. Mercieri- N. Northiana x N. mixta.—N Patersonii—N. Paradisae.—N. Paullii. Hort.—?—N. picturata-N. Dyeriana. G. M. 46:677. F.S.R. 2. p. 69.—N. Ratcliffiana-N. Hookeriana x N. Phyllamphora. G.Z. 26:241.—N. remilliensis—N. maxima var. superba x N. Northiana var. pulchra. — N. robusts-N. Hookeriana x N. Phyllamphora. G. C. II. 14:41. F. 1880, p. 156.— N. rufescens-N. distillatoria var. rubra x N. Courtii. A rare and rather unattractive hybrid. G. C. III. 4: 669. — N. Northiana-N. Phyllamphora x N. Sedenii. — N. Simonii -N. Northiana x N. mixta. — N. splendida-N. Hookeriana x N. Phyllamphora. — .V. Stewartii-N. Hookeriana x N. Phyllamphora. F. 1879, p. 157. — N. superba-N. Sedenii x N. Hookeriana.— N. Vallierae-N. Tiveyi x N. mixta. —Wrigleyana-N. Hookeriana x N. Phyllamphora.
More than 120 species of vines in this genus.
- Do you have cultivation info on this plant? Edit this section!
- Do you have propagation info on this plant? Edit this section!
Pests and diseases
- Do you have pest and disease info on this plant? Edit this section!
- Standard Cyclopedia of Horticulture, by L. H. Bailey, MacMillan Co., 1963