WikiBotanicals:Dendrobium

Dendrobium (from dendron, a tree, and bios, life;  the species are epiphytal in their native habitats). SYN. Pedilonum. A large and elegant genus of greenhouse orchids.

Background
A few species are very fragrant; but the scent of some is objectionable. Lip  more or less contracted at base into a claw, lying upon, or adnate to, the foot of the column ; pollinia four.


 * "The  genus," says Dr. Lindley, " varies extremely in the habit  of its species, some being little larger than the mosses  among which they grow, while others are surpassed in  stature by few of their order ..... There are some  species of which the foliage is ancipitous, others having  it terete, while, in the majority, it is in the usual flat  condition. A few have no other stems than a wiry creep-  ing rhizome; others have small conical pseudo-bulbs;  many form clavate horny stems, leafy only at the sum-  mit; but the greater part produce long leafy branches."

Cultivation
With but few exceptions, Dendrobiums are very easily managed; but it should be borne in mind  by those who undertake their culture, that they require  a decided period of rest, or "drying off," as the process is frequently termed. There is considerable diversity in  the habit and style of growth of the various members of  this genus; and, as many of the kinds not only thrive best,  but display their beauties to a greater advantage, when  suspended from the roof either in baskets or upon blocks  of wood, it will at once be obvious that by this means a large saving of space may be effected.

Placement
When placed in  baskets, they should be surrounded with a little rough  peat and sphagnum; but, when grown upon blocks, sphagnum only should be used, and this must be fastened with  some fine copper wire, which will also serve to fix the plant firmly. In putting orchids upon blocks, it is of  the highest importance that they should be firmly fixed;  if this is not done, they are, apt to get their first roots  damaged; but, as a rule, after they are once established, the roots will hold them tightly enough. Plants cultivated upon blocks require greater attention in the matter of water than those grown in pots.

Watering
During the  growing season, Dendrobiums should be sprinkled with  the syringe twice each day, morning and evening being  the best times to perform the operation ; in addition, it  will also be necessary to lift them down twice or three  times a week, and give them a dipping in a tub of water. This requires care, in order to preserve the  roots and young immature growths from injury; for, at  this period, both roots and shoots are very tender and brittle. It must be remembered, in syringing, dipping,  or otherwise, that cold water is highly injurious; therefore, it should be warmed to the same temperature as that of the house. As the growths reach maturity,  withhold the water supply, and remove the plants into  a cooler and drier atmosphere, with full exposure to light and sunshine, to thoroughly ripen them. Water must  be very cautiously applied during the resting period, as it is liable to start the plants prematurely. Sufficient water only must be given to prevent shriveling.

Drainage
Dendrobiums in pots should be planted in equal parts  fibrous peat and sphagnum, with a liberal addition of charcoal. They require to be elevated upon a cone of soil  above the rim of the pot, and should be pressed down, or potted firmly. Perfect drainage is absolutely essential to success. In pots, they enjoy a liberal supply of water during their period of growth; but care must be exercised when syringing, as the water is apt to lie in the sheaths of the young pseudo-bulbs, and cause injury. The plants are subject to the attacks of Yellow Fly when young, and to Scale when they are mature. The first-named pest must be exterminated on its earliest appearance.

Flowering
Dendrobiums, when in flower, may be used for almost any purpose of decoration. They beautify the plant house, the majority of them lasting several weeks in perfection, if not sprinkled with water from the syringe. They may be taken into the house, and will be found charming subjects for the living area; while many of them take first rank as subjects for exhibition. The enumeration of species is confined to such as are of known excellence. Many  species, and some of the varieties that are  periodically figured and described at length, are frequently  rare and often unique; and, for various reasons, it is probable that the majority of these do not become common or obtainable for many years afterwards.

Species
D. aduncum (hooked), flower. white, tinged with rose, small, appearing at different times of the year. h. 2ft. Manilla, 1842. An evergreen species, with a rather straggling habit. (B. R. 1846, 15.)

D. albo-sanguineum (white and crimson). flower. soft creamy-white, twin or tern, very large, about 4in. across ; petals twice as broad  as the sepals, with a few blood-red streaks at the base ; labellum with a large reddish-crimson blotch in the middle. May and June. Pseudo-bulbs from a few inches to 1ft. long, and nearly 1in. in diameter. Moulmein, 1851. Stove. (P. F. G. 57.)

D. album (white). A synonym of D. agueum.

D. amoenum (pleasing), flower. pure white, tipped with violet-purple,  scattered along the long slender stems, violet-scented ; throat  yellow ; labellum white, with a slight tinge of magenta at the base. Pseudo-bulbs 1ft. to 1 1/2ft. long. Himalaya, 1843. A slender-growing pendulous stove deciduous species. (B. M. 6199.)

D. Aphrodite (Aphrodite). flower. amber, produced sparingly from the  nodes of the last matured growth ; lip bright orange, margined with white, and with a large blood-red spot at the base. July. Pseudo-bulbs 4in. to 8in. high, 1/2in. in diameter through the very  prominent nodes, which are a distinguishing feature in the present species. Moulmein, 1862. Erect greenhouse deciduous species. SYN. D. nodatum. (F. d. S. 1582.)

D. aqueum (watery), flower. creamy-white, solitary or two together,  large, rising from the axils of the leaves ; lip recurved from  the middle, ovate-rhomboid, obscurely three-lobed; two lateral  lobes small, the intermediate one triangular ; the lower half  has an elevated ridge, and under its termination a depression,  and that part has a deep yellow blotch ; under side glabrous, the upper surface very downy and striated. Stem stout, jointed, compressed, striated, leafy (at the  time of flowering), yellow-green. Bombay, 1842. Stove. (B. M. 4640.) SYN. D. album.

D. aureum (golden). flower. amber, produced from the nodes of  two-year-old pseudo-bulbs, in bunches of from four to six, very fragrant ; lip amber, with brown and purple markings. February. Pseudo-bulbs 1ft. to 1 1/2ft. long, 3/4in. in diameter. India, 1837. A pendulous stove or greenhouse deciduous species. SYN. D. heterocarpum. (B. M. 4708.) The variety philippinensis is a remarkable long-stemmed form, with slightly scented Primrose-coloured flowers. 1880.

D. barbatulum (small-bearded). flower. ivory-white, with a slight tinge of pink, small, in dense erect racemes. East Indies, 1844. A robust greenhouse plant, attaining about 1ft. in length, and succeeding best on a block of wood. (B. M. 5918.)

D. Bensoniæ (Benson's).* flower. about 2in. across, produced in twos or threes at the end of the stem; sepals and petals waxy-white; lip white, with an orange centre, and ornamented near the base with two large velvety-black blotches. May and June. Burmah, 1867. An erect, stiff-growing, greenhouse deciduous species, with pseudo-bulbs 1ft. to 1 1/2ft, long, and about 1/2in. in diameter. (B. M.  5679.) Two varieties of this fine plant have been introduced :  aurantiacum (orange, brown), Moulmein, 1874 ; and xanthinum (white, yellow), 1878.

D. bigibbum (double-spurred).* flower. rich rosy-pink, 1in. to 2in. across, disposed in six to twelve-flowered arching spikes, which are produced from the leafy part of one-year and older bulbs. September and October. Pseudo-bulbs 1ft. to 1 1/2ft. long, carrying on their upper part from four to six closely-arranged leaves, h. 1ft. Queensland. An erect-growing stove evergreen species (B. M. 4898. ) The variety superbum grows somewhat stiffer and  stouter than the type, and has superior flowers, both in size and colour. 1878. (F. M. n. s. 229.) There is also a form (candidum) with white flowers.

D. binoculare (two-eyed), flower. copper-coloured, rather small;  apex of the lip golden-yellow, with one large brownish or purplish blotch on each side of its disk; raceme sub-erect. Summer. Burmah, 1869. A tall, slender-growing greenhouse species.

D. Boxallii (Boxall's). flower. scattered along the previous year's knotty growth, 2in. across ; sepals and petals white, beautifully  tipped with purple; lip same colour, with a large blotch of rich yellow. February and March. Pseudo-bulbs from 2ft. to 3ft. long, and 1/4in. through the nodes. Moulmein. An elegant stove  deciduous species, particularly adapted, from its pendulous habit, for growing on a block, although it thrives well under pot culture. (F. M. n. s. 114.)

D. Brymerianum (Brymer's). flower. solitary or in pairs, or in short  spikes of threes and fours from the upper part of two-year and  older bulbs; sepals and petals glossy yellow; lip yellow, furnished with a very deep, branched, papillose fringe. March and April. Length about 5in. long and 1in. broad, light green. Pseudo-bulbs 2ft. high, and 1/2in. in diameter, bearing from eight to twelve leaves. Burmah, 1875. A very remarkable and handsome erect-growing stove evergreen species. (B. M. 6383.)

D. Bullerianum (Buller's). A synonym of D. gratiosissimum.

D. Calceolaria (slipper-like), flower. of a uniform bright yellow, large, produced on a raceme twelve or more together. Summer. Pseudo-bulbs about 4ft. high. India, 1820. A large-growing stove evergreen species. Its name is usually misspelt D. Calceolus.

D. Cambridgeanum (Duke of Cambridge's). A synonym of C. ochreatum.

D. cariniferum (keel-bearing). flower white, in branches of four or more from one-year and older bulbs; sepals tinged with yellow at the tips; labellum orange, tipped with white, and furnished with a cinnabar-red crest. April. Pseudo-bulbs erect, evergreen, 1ft. long by 1/2in. in diameter. Burmah, 1869. Greenhouse. Varieties:
 * D. c. Wattii (Watt's). This differs from the type in its larger  flowers, rather longer spur, the longer narrow mid-lobe, the yellow  bands of the lip, and the faintly hairy sheaths. Munipore, 1883. (B. M. 6715.)

D. chlorops (green-eyed), flower. pale nankeen-colour; base of lip bright pea-green, small. Bombay, 1842. A very pretty free-flowering stove species.

D. chrysanthum (golden-flowered). flower. deep rich yellow, in twos  and threes on the leafy stems; labellum fringed, and having a dark crimson blotch. September. Pseudo-bulbs from 3ft. to 6ft. long, about 1/2in. in diameter. Nepaul, 1828. A handsome  greenhouse deciduous species, most successfully grown in a basket, suspended from the roof. (B. B. 1299.) The variety microphthalmum has the fringe of lip very short, blotches two or four, pallid brown, 1879.

D. chrysotis (golden). flower. about 2in. across ; sepals and petals  long and narrow, rich golden-yellow ; lip orange, with two large  purple blotches at the base, heavily fringed or bearded ; racemes drooping, several springing from one bulb, four to eight-flowered. Summer. Pseudo-bulbs 2ft. to 6ft. long, 1/4in. in diameter, with  dark, rather prominent nodes to every inch or two of the slender, rod-like stem. Assam, 1878. A very magnificent erect stove evergreen species, closely allied to D. fimbriatum (B. M. 6013, under name of D. Hoolcerianum.)

D. chrysotoxum (golden-arched). flower. over 1in. across, produced  from the leafy part of both old and young pseudo-bulbs; sepals  and petals pale yellow; lip a deeper yellow; raceme drooping, 6in. to 12in. long. March and April. Pseudo-bulbs 1ft. long, and 1 1/2in. in diameter, bearing from four to six stout leaves arranged on the upper part. Moulmein, 1845. A strong, erect stove evergreen species. (B. M. 5053.)

D. clavatum (club-shaped). flower bright yellow, with a crimson  spot in the centre of the lip, produced in drooping spikes from the tops of the stems. Summer. Pseudo-bulbs 1ft. to 3ft. high, and 1/2in. in diameter. From six to eight leaves clothe the upper part of the stem. Assam, 1851. An erect stove evergreen species, best adapted for growing in pots, in a peat soil. (L. & P. F. U. ii. 189.)

D. crassinode (thick-knotted). flower from the last matured growth, each node producing from two to four stoat blossoms; sepals and petals waxy-white, tipped with rich purple; lip white; with an orange blotch at the base. February and March. Pseudo-bulbs 1.ft. to 1 1/2ft. long, and 1/2 in. in diameter. Burmah, 1868. This species is remarkable for the enormously swollen joints of the stem, which are 1in. in diameter, and arranged about 1in. apart. A pendulous stove deciduous species, best grown in a small basket or on a block of wood. (B. M. 5766.) There are two or three very good varieties, including albiflorum, pure white, with a dark yellow disk; and Barberianum, a great improvement on the type, with more highly-coloured flowers, which are of greeter substance, the pseudo-bulbs also are stouter.

D. crepidatum (slippered). flower from the last matured growth, two and three together, about 2in. across, on somewhat long footstalks; sepals and petals white, tipped with pink; lip stand with yellow. March. Pseudo-bulbs 1ft. to 1 1/2 ft. long, with white lines running their entire length. Assam. A very handsome drooping greenhouse deciduous species, well suited for growing in a basket or on a block. (B. M. 4993.)

D. cretaceum (chalked). flower chalky-white, solitary from the joints of the long leafless stems, rather small, downy; lip with a pale yellow disk, pencilled with crimson; margin ciliated. May. Pseudo-bulbs 8in. to 14in. long, 1/2in. in diameter. India, 1846. A compact-growing pendulous stove deciduous species. (B. M. 4686.)

D. crystallinum (crystalline). flower of moderate size, freely produced from the last matured growth; sepals and petals white, tipped with rose or purple; lip orange at the base, tipped with purple. Summer. Pseudo-bulbs 1ft. to 1 1/2ft. long, 1/2in. in diameter. Burmah. 1868. An erect-growing stove deciduous species, allied to D. Bensoniae. (B. M. 6319.)

D. cucullatum (hooded). flower 1 1/2 in. to 2 in. in diameter, suffused with a pale pink tint; lip pale yellow. India, 1835. Very closely allied to D. Pierardii, from which it is principally distinguished by the lip being more ovate in form and more open at the base, the sides not being rolled round the column to half the extent they are in D. Perardii, to which, however, the present species is inferior from a horticultural point of view. Greenhouse. (B. M. 2242.)

D. cupreum (coppery). A synonym of ''D. moschatum.

D. Dalhousianum (Lady Dalhousie's). flower large, 3in. to 5in. across; sepals and petals buff, shaded with pale lemon; lip of the same color, spotted at the base with two large blotches of dark crimson, and margined with rosy-pink; racemes drooping, produced from the growth of the previous year, six to ten-flowered. April and May. Pseudo-bulbs stout, erect, 3ft. to 5ft. high, about 1in. in diameter, with purple lines running their entire length. India, 1837. A noble strong-growing stove evergreen species, requiring, however, a considerable space to grow it in anything like perfection. (P. M. B. xi. 145)

D. Devonianum (Duke of Devonshire's) flower sepals and petals soft creamy-white, tinged with pink, the latter in addition being tipped with purplish-magenta; lip white, margined with purple and spotted with rich orange at the base, and bordered all round with a delicate lace-like frill, which gives the plant a charm that is quite unique. Well-grown pseudo-bulbs often carry from ninety to hundred flowers, which are about 2in. across. March and April. Pseudo-bulbs 1ft. to 3ft. long, 1/2in. in diameter. East Indies, 1837. A very beautiful pendulous stove deciduous species, sometimes called the King of Dendrobiums. It should be grown either in a basket or upon a block of wood. (B. M. 4429.) Varieties:
 * D. D. candidulum (white). flower pure white, with a yellow throat.  1876.
 * D. D. Elliottianum (Elliott's). flower sepals and petals with much purple on their tips; whole flower veined with rose.  1876.
 * D. D. rhodoneurum (red-veined). flower sepals and petals streaked with dark purple; lip large and round. Moulmein, 1868.

D. dixanthum (double-tinted). flower yellow, produced in clusters of from two to four together, on the leafless stems; disk of the lip of a darker hue, about 2in. across. Spring. Pseudo-bulbs about 2ft. high and 1/2in. in diameter. Moulmein, 1864. An erect, slender-growing, stove deciduous species. (B. M. 5564.)

D. Draconis (Draco). flower white, moderate-sized produced from the points of the last matured growths in bunches of six or more; lip with a red base. Pseudo-bulbs 1ft. to 1 1/2ft. high, 1/2in. in diameter. Moulmein, 1862. Erect stove evergreen. SYN. D. eburneum. (B. M. 5459.)

D. eburneum (ivory-flowered). A synonym of C. Droconis.

D. erythroxanthum (red-yellow) flower orange, striped with  purple, small, densely clustered, produced from the last matured growth. May and June, Pseudo-bulbs 3ft. to 4ft. high, about 1 1/2in. in diameter. Philippines, 1874. A very rare, erect, stove deciduous species.

D. Falconeri (Falconer's) flower produced from one-year and older nodes; sepals and petals white, tipped with purple; lip same color, with a centre of dark purple, margined with orange. May. length 3in. long, 1/4in. broad. Pseudo-bulbs about 3ft. long, very knotty, much-branched; nodes 1/4in. in diameter, very close together. India, 1847. A pendulous stove evergreen, somewhat difficult to cultivate. (B. M. 4944.)

D. F. albidulum (white) flower pure white, slightly tinged with purple at the tips of the sepals, petals, and lip. India, 1876. (B. H. 1874, 15.)

D. F. giganteum (gigantic). flower the same in colour as the type. Length 3in. long, 1in. broad. Pseudo-bulbs 1ft. to 1 1/2ft. long, unbranched; nodes 1/4in. in diameter, about 1in. apart. An erect or semi-erect form.

D. Farmeri (Farmer's). flower produced upon long pendulous racemes, in the same manner as those of D. densiflorum, but not so closely set together; sepals and petals pale straw-colour, delicately tinged with pink, whilst the disk of the lip is of a golden-yellow. May. India, 1847. A beautiful and delicate upright-growing stove evergreen species, attaining about 1ft. in height, bearing several shining dark green leaves towards the top of its club-shaped stems, which are swollen at the base into a kind of pseudo-bulb. (B. M. 4659.) Varieties:
 * D. F. aureoflavum (golden-yellow). A beautiful variety, distinguished from the type by its bright yellow sepals and petals, and golden lip.  Moulmein, 1864.  (B. M. 5451.)  There is also a white variety, album, but both are rare.

D. fimbriatum (fimbriated). flower about 2in. across, of a thin and delicate texture throughout, deep rich orange; margin of lip beautifully bordered with a golden moss-like fringe; racemes pendulous, six or more flowered, from the upper part of three-year and older pseudo-bulbs. March and April. Pseudo-bulbs 2ft. to 4ft. long, 1/2in. in diameter, having thirty to forty leaves, which are 6in. long by 1 1/2in. broad. India, 1823. A very showy erect stove evergreen species. Varieties:
 * D. f. oculatum (eyed). A very handsome variety, chiefly differing from the type in having larger flowers, the lips of which are blotched in the centre with deep blackish-purple or dark blood-colour.  India.  SYN. D. Paxtoni.  (B. M. 4160.)

D. Findlayanum (Findlays's) flower 2in. to 3in. across, produced from the upper nodes of the last matured pseudo-bulbs; sepals and petals white, tipped with pink; lip white, with a large orange-coloured blotch on the anterior part. January and February. Pseudo-bulbs 1ft. or more high; remarkable for the large egg-shaped nodes, which are over 1/2in. in diameter and 1in. long. Moulmein, 1877. An erect stove deciduous species. (B. M. 6438.)

D. formosum (beautiful). flower white, 4in. to 6in. across, of great substance, produced from the point, and also from the axils, of the leaves nearest the point of the pseudo-bulb; lip large, white, with an orange throat; spikes three to four, or even eight-flowered. Summer. Pseudo-bulbs 1ft. to 1 1/2 ft. high, 1in. in diameter, bearing about eight or ten coriaceous leaves. India, 1837. Stove. (B. R. 1839, 64.)

D. Fytchianum (Fytch's). flower borne in graceful racemes, 9in. long, proceeding from the extremity of the upright stems; perianth beautiful white; lip three-lobed; lateral lobes small, oblong, incurved, purplish-rose. January. Length slender, linear, falling off before the flowers have had time to expand. Stem about 1ft. long, upright. Moulmein, 1864. Stove. (B. M. 5444, under the name of D. barbatulum.)

D. Gibsoni (Gibson's). flower rich orange, produced on the ends of the old pseudo-bulbs; lip bright yellow, with two dark spots on the upper part. Summer. Height 2ft. Khasys, 1827. A pretty, erect-growing evergreen stove species, closely resembling D. fimbriatum oculatum, but the lip is longitudinally plicate. (P. M. B. v., p. 169.)

D. gratiosissimum (most-favoured). flower usually in pairs; sepals and petals white, shaded and tipped with rose; lip marked with a large yellow spot, which is faintly striped with orange. Length ovate-lanceolate, acute. Moulmein, 1867. Stove. SYN. D. Bullerianum. (B. M. 5652.)

D. Griffithianum (Griffith's). flower very rich golden-yellow, disposed in immense drooping spikes. May and June. East Indies, 1838. Described as one of the most beautiful of the yellow spring-flowering section, not unlike D. densiflorum, but about double the size in all its parts. Stove.

D. hedyosmum (sweet-scented). A synonym of D. scabrilingue.

D. heterocarpum (variable-fruited). A synonym of D. aureum.

D. Heyneanum (Heyne's). flower white, streaked with  violet, small, produced in spikes, from the top of the stems, at different times of the year. Bombay, 1838. A very pretty stove deciduous species, growing about 8in. high, and best cultivated on a block.

D. infundibulum (funnel-shaped). flower pure ivory- white, large, often 4in. across, produced in bunches of two or more blossoms, from the upper joints; lip serrated, yellow ; the bases of the two lateral sepals prolonged into a tapering funnel-shaped spur, about 1in. long. May and June. Pseudo-bulbs 1ft. to 1 1/2 ft. long, 1/2in. in diameter, bearing ten to fourteen strong leaves. Moulmein, 1863. Stove. It thrives best in a  pot nearly filled with draining material, and over this a layer of living sphagnum. (B. M. 5446. )

D. Jamesianum (James Veitch's) differs only from D. infundibulum in having a red, instead of a golden, throat. Moulmein, 1869. Stove. There are several  other forms of these two species, the differences of which lie in the colouring of the lip.

D. Jenkinsii (Jenkins's). flower pale buff, margined with  yellow, on short erect spikes of two or three good-sized  blossoms, from the centre of two-year and older pseudo- bulbs. March and April. Pseudo-bulbs small, growing thickly together, 1in. long, 1/2in. in diameter,  bearing a solitary, thick and fleshy, dark green leaf, which is almost 1in. long. Northern India, 1838. A  charming little greenhouse evergreen for growing on a bare block of wood. (B. R. 1839, 37.)

D. Jordonianum (Jerdon's). flower cinnabar-red, small,  produced in small bunches from the last matured growth ; lip dark purple. Pseudo-bulbs about 6in. high. Nilgherries, 1868. Erect stove evergreen.

D. Jonannis (John Veitch's). flower small, fragrant; sepals  and petals chocolate-brown; lip yellow, with crimson pencillings. North Australia, 1865. A very pretty greenhouse species, but not so showy as many others. (B. M. 5540.)

D. lasioglossum (woolly-tongued). flower somewhat small, produced in twos and threes from the joints; sepals and petals creamy-white; lip yellow in the centre and brown at the sides, streaked with purple lines. Pseudo-bulbs 8in. to 12in. long. Burmah, 1868. An erect slender-growing greenhouse species, but rather difficult to cultivate. (B. M. 5825.)

D. Linawianum (Linaw's). flower pale rosy-lilac, nearly white in the centre, produced freely in pairs; lip tipped with crimson. Winter. Height 1ft. or more. China, 1824. A very handsome erect-growing greenhouse evergreen species, requiring pot culture. (B. R. 1314, B. M. 4153, under name of D. moniliforme.) There is a variety majus, which has larger and richer-coloured flowers.

D. lituiflorum (trumpet-flowered). flower very much like those of D. nobile, but smaller; sepals and petals rosy-purple, very acute;  lip white, bordered with purple, having a dark purple centre, and remarkable in being curved like a trumpet, with the mouth upwards. April. Pseudo-bulbs 18in. to 20in. long, 1/2in. in diameter; node-like joints about 1 1/2in. apart. East Indies, 1856. A rare pendulous stove deciduous species, succeeding best when suspended from the roof in a basket of sphagnum. (B. M. 6050.) Varieties:
 * D. l. candidum (white). flower pure white, with the faintest tinge  of green on the lip. 1880. Very rare.
 * D. l. Freemanii (Freeman's). A deep-coloured form, with zone of  labellum yellow, and erect, short, stiff pseudo-bulbs. Assam, 1878.
 * D. longicornu majus (large long-spurred). flower white, fringed, freely produced from the upper part of two-year and older pseudo-bulbs, and from three to six together; lip with a yellow centre. May and June.  Pseudo-bulbs 18in. to 20in. high.  India.  Stove.  According to Mr. B.S. Williams, "there are two varieties, but the one now described is the best." Not unlike D formosum, but not so robust in growth.

D. Lowi (Low's). flower bright yellow, with reddish veins on the upper part of the lip, large, 2in. across, produced in racemes from the side of the stem near the top. Summer and autumn. Pseudo-bulbs 1ft to 1 1/2ft high, 1/4in. in diameter. Borneo. 1862.  A very distinct erect stove evergreen species, well-grown plants of which are very rare. It succeeds in a pot or basket, or on a block. (R M. 5303.)

D. luteolum (yellowish). flower primrose-yellow, with a little orange and crimson on the lip, 1in. to 2in. across, produced in threes or fours from the upper part of the last-made pseudo-bulbs and branches. March. Pseudo-bulbs 1ft. to 2 1/2ft. long, 1/4in. in diameter. Moulmein, 1864. An erect (or usually so) greenhouse evergreen. The bulbs of some plants of this species throw out many branches, but there is a variety which makes an erect bulb 30in. high. The first-named form never does well unless, each year, the nodes from which these new growths proceed are brought down so that the roots can enter the peat and sphagnum. (B. M. 5441.)

D. MacCarthiæ (Mrs. MacCarthy's). flower large, nearly 3in. in length, and somewhat more in width, produced in drooping racemes of from three to five blossoms ; sepals and petals very  pointed, of a rich cerise-blue; lip lighter, sometimes almost white, 3in. long, scoop-shaped, veined with purple, and with a large dark blotch within. June. Pseudo-bulbs 1 1/2ft to 2ft. long, 1/4in. in diameter. Ceylon, 1854. This is difficult to manage; it requires a high, moist, airy atmosphere to grow in, and should then be rested for some weeks in an intermediate temperature. It cannot withstand, even when at rest, a lower temperature than 50deg. (R M. 4886.)

D. macrophyllum (large-leaved). flower greenish-yellow, hairy outside, produced in long terminal erect Racemes; lip three-lobed, striped and spotted with purple. Philippines, 1833. A tall-growing stove species, with club-shaped stems, which bear two or three broad leaves. (R M. 5649.)

D. marmoratum (marbled). flower white, tipped with purple ; lip purplish, ciliated. Burmah, 1875. A very pretty stove species, allied to D. transparens.

D. moniliforme (beaded). flower white, with a few purple spots on the lip, deliciously fragrant, borne on the upper part of the  previous year's leafless stems, in clusters of two or more blossoms from a joint. May. Pseudo-bulbs thin, about lOin. high, clothed with grass-like leaves. China and Japan, 1824. Greenhouse. (B. M. 5482, under name of D. japonicum.) The D. moniliforme of Lindley (B. R. 1314) is D. Linawianum.

D. moschatum (musk-scented). flower creamy-white, tinged with rose, large, over 2in. across; lip slipper-shaped, pale yellow, base darker, ornamented on each side with a large eye-like blotch of deep blackish-purple; racemes from the upper part of one-year and older pseudo-bulbs, drooping, eight to fourteen-flowered. June. Pseudo-bulbs 3ft. to 5ft. high, 1/2in. in diameter; from twenty to thirty large leaves clothe the stem. East India, 1828. A very handsome but much neglected stove species, with an erect, evergreen, strong-growing habit. SYN. D. cupreum. (B. R. 1779.)

D. mutabile (changeable). flower white, or pinkish-white, with an orange mark on the lip, produced from the old pseudo-bulbs; spikes compactly eight to twelve-flowered. May. Pseudo-bulbs 4ft. to 6ft. long, frequently branched, and very leafy. East Indies, 1844. A delicate upright-growing stove evergreen species. SYN. D. triadenium. (B. M. 5285.)

D. nobile (noble). flower large, very freely produced from two-year-old pseudo-bulbs; sepals and petals white, tipped with rosy-pink ; lip white, rosy-pink in front, blotched at the base with deep velvety crimson. January to April. Pseudo-bulbs 2ft. to 3ft. high, 1/2in. in diameter, bearing from ten to sixteen bright green leaves. China, 1836. (G. C. n. s., xi. 564.) This greenhouse species is at once one of the oldest in cultivation, one of the best known, one of the easiest grown, one of the cheapest in commerce, and, withal, one of the most beautiful. It is an evergreen and should be treated with pot culture if a large specimen is required; smaller examples may be grown in a basket. When growth is complete, remove it to a cool house, and keep it dry. or with just sufficient moisture to preserve its pseudo-bulbs from shriveling. It usually flowers during  spring and early summer; if required to blossom in winter, it should be placed in the stove during the autumn months. This  is one of the species which vary their scent at different times of the day. According to M. Andre, the blossoms have an odor of  grass in the morning, of honey at noon, and a faint Primrose scent in the evening. There are several varieties, including the  following:
 * D. n. intermedium (intermediate). flower sepals and petals white; lip white, with a crimson spot in the centre. A rare, but distinct and desirable form.
 * D. n. pendulum (pendulous). flower large, richer in colour than the type ; with a pendulous habit.
 * Other varieties are : cœrulescens, nobilius (a very splendid form), and Wallichianum.

D. nodatum (noded). A synonym of D. Aphrodite.

D. ochreatum (yellowish). flower produced on the young growth, about 2in. across, very thick in substance; sepals and petals bright orange; lip with a crimson blotch in the centre. Pseudo-bulbs 8in. to lOin. long, nearly 1in. in diameter. Northern India, 1837. A very handsome pendulous stove deciduous plant SYN. D. Cambridgeanum. (B. M. 4450.)

D. Paxtoni (Paxton's). A synonym of D. fimbriatum oculatum.

D. Pierardii (Pierard's). flower creamy-white or delicate pink, produced on long, beautifully festooned stems: lip Primrose-colour, with a few purple lines near the base. Winter. Pseudo-bulbs 2ft. to 4ft. long, 1/3in. in diameter. East Indies, 1815. A pendulous greenhouse deciduous species, best grown in a basket or on a block. (B. M. 2584.) There are several varieties, some of which are very inferior. One of the best is D. P. latifolium, in which  the flowers are much finer than those of the type, and are rather more freely produced. It is rare. India, 1830.

D. primulinum (Primrose). flower produced in two rows along the  stem ; sepals and petals small, pinkish-white; lip downy, very large, shell-shaped, white, with a very faint tint of blue. February and March. Pseudo-bulbs 1ft. to 1 1/2ft. long, 1/2in. in diameter. Moulmein, 1864. A rare but handsome stove deciduous species, with a pendulous habit (B. M. 5003.)

D. pulchellum (beautiful). flower freely produced from the last  matured growth; sepals and petals pinkish-white; lip rose, with an orange base; margin beautifully fringed or ciliated. March. Pseudo-bulbs branched, 6in. to lOin. long. North India. A  dwarf stove deciduous species, requiring to be grown in a basket, and, when at rest, to be kept cool. (B. M. 5037.)

D. rhodocentrum (red-spurred). flower light rosy, produced from  the upper portions of the two-year and older pseudo-bulbs, and  disposed in hanging bunches of from six to twelve; petals tipped  with purple; lip white, with a purplish stain at the apex, and a yellowish base. Autumn. Pseudo-bulbs 2ft to 3ft long, 1/4in. in diameter. 1872. A pendulous stove evergreen species.

D. rhodopterygium (rose-winged). flower deep rose; lip light purple, woolly, pouched. May. Pseudo-bulbs 1ft. to 1 1/2ft high, 1/2in. in diameter. Burmah, 1875. An erect deciduous stove species, resembling D. Parishii, but with much larger pseudo- bulbs.

D. Ruckeri (Rucker's). flower. greenish-yellow, almost white externally, fragrant; lip with brown marking. Philippines, 1843. A pretty species, similar in habit to D. aureum.

D. sanguinolentum (blood-stained). flower produced in bunches of six or eight, from the upper parts of the old pseudo-bulbs;  sepals and petals amber, veined with rose, and with purple tips; lip large, with its point heavily marked with purple. Autumn. Pseudo-bulbs 3ft. to 4ft. high, 1/2in. in diameter, thickly clothed with large dark green leaves. Ceylon, 1842. An erect stove evergreen species, with violet or lilac-coloured stems and leaves. (B. R. 1843, 6.) Mr. Williams mentions a variety named superbum which he describes as a great improvement upon the typical form ;  it is much stronger in growth, with longer spikes and larger flowers. Borneo.

D. scabrilingue (rough-tongned). flower at first greenish, but soon  changing to pure white, except the lip, which is shaded with green and yellow, and striped with orange; rather small, produced in pairs, and yielding a very delicious Wallflower-like perfume. Spring. Pseudo-bulbs 6in. to lOin. long, and about 1/3in. in diameter. Burmah, 1862. An erect stove evergreen species. SYN. D. hedyosmum. (B. M. 5515.)

D. sculptum (carved). JL pure white, about 2m. across, produced  from the top of the matured growth, three or four on a spike ; lip white, a square orange blotch on its centre. Pseudo-bulbs 1ft to lift long, in- thick. Borneo. An erect stove evergreen.

D. senile (white-haired). flower bright golden-yellow, about 1in. across, in short spikes of twos or threes from the sides of the last matured growth; lip with a few reddish transverse stripes. Spring. Pseudo-bulbs 4in. to 6in. long. 1/2in. in diameter. Moulmein, 1865. (B. M. 5520.) A rare but pretty erect stove  deciduous species, having the stems and leaves densely clothed with long white hairs. This plant should be grown upon a block of wood, and kept surrounded with a genial atmosphere; but it does not enjoy overhead syringing.

D. speciosum (showy). flower wax-like, creamy or yellowish-white,  fragrant, small, but numerously disposed in a long terminal raceme (from 1ft. to 1 1/2ft. in length), curiously resupinate or  inverted, the lip appearing at the upper part of the flower; sepals and petals incurved, narrow; lip with black specks. Autumn. Pseudo-bulbs very stout, 6in. to lOin. long, 1 1/2in. diameter, crowned with two or three large coriaceous dark shining leaves. Eastern Australia, 1824. An erect greenhouse evergreen species, extremely easy to manage. When making its young growths, little heat is necessary; but when these are mature, it should be removed to the open air for two or three months, giving only sufficient water to keep the sun from shriveling it up. It should be grown in a pot and a little loam and leaf mould may be added to the compost with considerable advantage. (B. M. 3074.) Varities:
 * D. s. Hillii (Hill's). flower sepals and petals narrower and paler,  and with longer but more slender spikes than those of the type.  Pseudo-bulbs about double the length, and half the thickness, of  those of D. speciosum. 1861. A remarkably floriferous plant  (B. M. 5261.)

D suavissimum (very sweet-scented). flower rich yellow, about 2 1/2in. across, with a strong Hawthorn-like fragrance, produced in  erect spikes of eight to twelve, from the leafy part of one-year  and older pseudo-bulbs; lip the same colour, with a conspicuous  central blotch of brownish-purple; outer edge very delicately fringed. June. Burmah, 1873. Habit of growth the same as D. chrysotoxum. Stove. (Gn., Feb. 23, 1878.)

D. sulcatum (furrowed). flower in a drooping raceme from the leafy  joints; sepals and petals amber, with crimson veins; lip amber, with deep crimson markings. February. Pseudo-bulbs 6in. to 9in. high, swelling upwards, bearing two or three large leaves in the upper part. India, 1837. An erect stove evergreen species. (B. R. 1838; 65.)

D. superbiens (superb). flower usually light purple, but sometimes claret, shaded with brown, about 2in. across; spikes erect or  arching, bearing from eight to twelve flowers, and produced  from the upper part of the pseudo-bulbs; sepals and petals undulated or waved. Autumn. Pseudo-bulbs 1ft. to 3ft. high, 1in. in diameter. North Australia, 1876. An erect stove evergreen species. (Gn., Sept 14, 1878.) Variety:
 * D. s. Goldiei (Goldie's) A very elegant form, with violet-  coloured flowers. North Australia, 1878

D. superbum (superb). flower pink, tinged with rose, about 3in. or 4in. across, proceeding in a 'row on each side of the stems; lip rich purple. ApriL. Pseudo-bulbs 1 1/2ft. to 2ft. long, 1/4in. in diameter. Philippines. A pendulous stove semi-deciduous species, with flowers having a strong odor, like Turkey rhubarb; this objection will be unnoticed if the plant is grown in a basket suspended from the roof. (B. M. 3970, under the name of D. macranthum.) Varieties:
 * D. s. anosmum (scentless). flower large, from 2in. to 3in. across, produced in pairs down the stem; sepals and petals rosy-pink;  lip purple. Spring. Pseudo-bulbs 1ft. to 2ft. long, and about  1/4in. in diameter. Manilla, 1840. A drooping stove deciduous  species, best grown in a basket. Reichenbach considers this a  variety of D. superbum, but the petals and sepals an broader,  and the flowers are better-shaped and have no rhubarb scent  (P. M. B. xv. 97.)
 * D. s. giganteum (gigantic). flower from 5in. to 7in. across; sepals  and petals rose-purple; lip same colour, fringed and marked at  the base with two purplish-red spots. Pseudo-bulbs much shorter  and thicker than in the type. Manilla.
 * D. s. Huttonii (Hutton's). flower sepals and petals pure white;  lip downy, brilliant purple on the inside. This splendid, but rare,  variety is almost entirely without the rhubarb scent of the type.  Malay Archipelago. There are two or three other varieties.

D. Tattonianum (Tatton's). A synonym of D. canaliculatum.

D taurinum (bull-beaded). flower sepals yellowish-green; petals  deep purple, long, curling, and spread out like the horns of a bull (whence the specific name); lip white, margined with purplish-violet. Autumn. Height 5ft. Manila, 1837. A strong-growing stove evergreen species, with upright stems; it is best grown in a pot. (B. R. 1843, 28)

D. teretifolium (terete-leaved). flower white, numerously produced in short bunches from the base of the pseudo-bulb; lip with black specks. October. Pseudo-bulbs small, much jointed, branching, bearing at their points a solitary terete pendulous leaf, which is 9in. long by 1/4in. in diameter. Northeast Australia, 1823. A pendulous stove evergreen species. (B. M. 4711.)

D. thyrsiflorum (thyrse-flowered). A synonym of D. densiflorum albo-luteum.

D. tortile (twisted). flower pale yellow, almost white, suffused with purplish-rose; sepals and petals long, slightly twisted. June. Pseudo-bulbs 1ft. to 1 1/2ft. high, 3/4in. in diameter. Moulmein, 1847. An erect stove evergreen species, flowering in the same manner as D. nobile. (B. M. 4477.) The variety roseum is extremely pretty, having flowers of a delicate rose, shaded with yellow. It resembles the type in every other respect.

D. transparens (transparent). flower transparent white, tinged with purplish-rose towards the tips, 1in. to 1 1/2in. across, produced in pairs along the stems; lip stained in the middle with a blotch of deep crimson encircled by a yellow zone. March. Pseudo-bulbs 1ft. to 1 1/2ft. high. Assam, &c. An elegant, slender, erect stove deciduous plant. (B. M. 4663.)

D. triadenium (three-gland-lipped). A synonym of D. mutabile.

D. Wardianum (Ward's). flower about 3 1/2in. in diameter, thirty to  forty to a pseudo-bulb; sepals and petals white, upper portion  bright rich magenta, broad, thick, wavy, blunt at the tips; lip  large, white above, rich orange in the lower part, with two deep eye-like spots of crimson-magenta. May. Pseudo-bulbs 2ft. to 4ft. long, 1in. in diameter; nodes about l 1/2in. apart. Assam, 1863. A splendid stove deciduous species, requiring to be cultivated in a basket or upon a block of wood, as its stems are long and pendulous, the joints much swollen. During the growing season, it enjoys  an abundant supply of water, with a good heat; but, when the growths are complete, the plant should be removed to a cooler atmosphere, and less water, as a matter of course, will suffice. The two following varieties are both rare and very desirable: candidum (=album) sepals and petals pure white; lip the same, but with an orange-coloured base. (F. M. n. s. 212.) Lowii, flowers white, rose, purple-brown.

D. Williamsonii (Williamson's). flower ivory-white, slightly tinged with brown; lip large, with a blood-red spot. Stems erect, bearing strap-shaped leaves, clothed with short soft hairs. Assam, 1869. Stove plant, somewhat difficult to cultivate.

D. xanthophlebium (yellow- veined). flower produced in pairs upon  the last matured and older pseudo-bulbs; sepals and petals white; lip medium-sized, spotted with orange; margin white. Pseudo-bulbs very small. Height 1ft. Moulmein, 1864. Stove.