Part 15

ODONTOGLOSSUM VEXILLARIUM.

BROAD-LIPPED ODONTOGLOSSUM.

O. (PHALÆNOPSIDEA) pseudobulbis ovato-oblongis compressis 1-2-phyllis; foliis pedalibus subglaucescentibus carinatis lanceolatis acutis pedunculis gracilibus 2-6-floris subæqualibus; bracteis triangulis minutis; floribus maximis roseo suffusis; sepalis oblongo-ligulatis apiculatis; petalis conformibus vel paulò latioribus subacutis vel obtusis; labello maximio flabellato orbiculari bilobo, in unguem brevem hastatum contracto, carinis quinis abruptis in basi; columnâ brevissimâ exalatâ.

ODONTOGLOSSUM VEXILLARIUM, Rchb. fil. in Gard. Chron. 1867, 901; ibid. 1872, p. 667, cum Xylo; 1873, p. 580, 644, cum Xylo, 885; Hooker in Bot. Mag. t. 6037; Illustration Horticole, 1873, Pl. cxiii.

Habitat in N. GRENADA, Bowman, Wallis, Roezl, Chesterton.

DESCRIPTION.

PSEUDOBULBS flattened, ovate-oblong, an inch or inch and a half long, bearing one or two keeled sharp-ended lanceolate LEAVES from six inches to a foot long, by an inch or more wide, with a glaucous tint, especially on their upper surface. SCAPES slender, nodding, about the same length as the leaves, two to six-flowered, clasped at intervals by small triangular BRACTS. FLOWERS flat, the largest in the genus, tinted more or less deeply with lovely rose. SEPALS and PETALS somewhat variable in their relative forms, in most cases nearly the same size, oblong or obovate apiculate or obtuse, about an inch long, the former nearly white, the latter of the same hue as the lip. LIP generally of a rich rosy tint, expanding from a narrow sagittate claw into a round and ample, 2-lobed disk, more than double the size of the petals, with five dwarf calli and some yellow streaks at its base. COLUMN very short with rarely a trace of wings.

This is the handsomest of known Odontoglossa. In the year 1867 Mr. Low showed me a solitary flower, which had been sent to him by his collector (Bowman, I believe), but a discreet silence was observed as to the locality where the prodigy had been found, nor, alas, did living plants ever make their way to the Clapton Nursery. Subsequently the species was met with by Wallis--when collecting for Mr. Linden--and later still by Roezl; but although in each case a large number of specimens were packed up and despatched to Europe, they either died on the passage, or shortly after their arrival. Indeed, cultivators were almost beginning to despair, when, early in the spring of last year (1873), the arrival was announced of a small cargo of the beauteous novelty in most excellent condition at the establishment of Messrs. Veitch; to whom it had been forwarded by Mr. Henry Chesterton. Once safe in the Chelsea collection, it did not put the patience of Orchid-growers to any severe strain, for within little more than three months of its arrival vigorous flower-spikes were produced, and the plant itself exhibited--both in Regent's Park and at South Kensington--to the envy and admiration of all beholders. It seems to be very easy to manage, and produces its flower-scapes with the utmost profusion. Like all its congeners, it must be relegated to the cool Orchid-house, though probably it will be found to prefer the warmest end.

Professor Reichenbach has written several articles in the Gardeners' Chronicle about this plant, in one of which he deplores, and most justly, the wanton waste and havoc committed by collectors; who, instead of contenting themselves with a moderate number of specimens, gather them by hundreds, or even by thousands, thus imperilling the very existence of species which, like the present, are believed to possess only a very restricted habitat. Nor does this recklessness often benefit their employers, for in most cases, the larger the consignment, the smaller the chance of its prospering on its way.

The woodcut is copied from a photograph of a small specimen of O. vexillarium, taken in New Grenada, in the act of flowering.

Plate XXX

PLATE XXX.

ODONTOGLOSSUM ROEZLII.

ROEZL'S ODONTOGLOSSUM.

O. (PHALÆNOPSIDEA) affine O. vexillario, pseudobulbis ovato-oblongis ancipitibus compressis 1-2-phyllis, foliis lineari-ligulatis inferne striatis pedunculis 1-3-floris longioribus; sepalis oblongo-ligulatis acutis, petalis sublatioribus; labello a basi angustâ sagittatâ cuneato flabellato obtuse bilobo; carinis ternis in imâ basi; prepositâ lamellâ transversâ seu callis parvis geminis; columnâ apterâ.

ODONTOGLOSSUM ROEZLII, Rchb. fil. Xenia Orchidacea, ii.; idem in Gard. Chron. p. 1302, (cum Xylo) 1873.

Habitat in N. GRENADA, Roezl; Backhouse in Gard. Chron. p. 1334, (1873).

DESCRIPTION.

A compact plant, of which the PSEUDOBULBS are ovate-oblong, 1-2 inches long and much compressed; these bear one or two bright green linear acute LEAVES, which are remarkable for their parallel streaks--nine in number--on the under side, and are from six to ten inches long, and about ½ inch wide. The SCAPES or PEDUNCLES are shorter than the leaves, and bear from one to three (possibly more) large and beautiful flowers, which with the exception of some markings at the base of the petals and on the lip are of snowy whiteness. SEPALS oblong-ligulate pointed at the extremity, fully an inch long. PETALS rather wider than the sepals and with a rich crimson blotch at their base. LIP wedge-shaped, expanding from a narrow sagittate base into a broad two-lobed disk, an inch and a half wide, white with some bright yellow markings near the foot and in the region of the CREST; the latter being formed by three slightly raised "carinæ" or ridges near the base on either side, traversed by two moderate sized calli placed in front. COLUMN wingless.

This is a most charming Odontoglossum, allied to the preceding and to O. phalænopsis, but perfectly distinct from either. Its bright green narrow leaves--streaked like those of Saccolabium Blumei, at once distinguish the plant, even when out of flower, from its fascinating rival O. vexillarium; which always bears a glaucous hue, and which has larger and broader foliage, and produces double the number of flowers on a scape. The first rumours that reached us of the plant led to a suspicion that it might, after all, be only a variety of O. vexillarium, but these unworthy fears were at once dispelled by the flowering of the plant itself at Mr. Bull's nursery in the early part of last September, when Mr. Fitch prepared his drawing, and Professor Reichenbach obtained materials for the description which appeared in the Gardeners' Chronicle of September 27, 1873. The Professor has also given, in his Xenia, a characteristic representation of the wild plant constructed from the specimens supplied to him by its fortunate discoverer, Mr. Roezl; in whose honour the species is very properly named. It is a native of New Grenada, and, like O. vexillarium, appears to be exceedingly rare; we must not, therefore, murmur if the precise locality--of which the knowledge is a fortune in itself--should be for awhile withheld. But there would have been no harm in telling us the approximate elevation of the native habitat, as the same is always important as a clue to culture; especially in the case of plants with a limited range. In this instance I apprehend that both O. Roezlii and O. vexillarium are not found at a very high level and that therefore--though happily entitled to rank among "cool" Orchids--they must be placed in the warmer division of the "cool" Orchid-house.

The woodcut represents, for purposes of comparison, two nearly allied Odontoglossa, viz., O. pulchellum and O. Egertonianum; they both come from the same country (Guatemala) and closely resemble each other in habit--only that the pseudobulbs of the latter have much the sharper edges--but the flowers are very different. The spikes of O. Egertonianum (2) are a sort of Orchid-imitation of the racemes of the "Lily of the Valley," though unfortunately they have no perfume, while those of O. pulchellum (1) emit a delicious, almond-like odour, not very unlike that of Gardenia radicans; they are, moreover, very chaste and beautiful, and are freely produced during the winter months. Under these circumstances the species has long since become, what it well deserved to be, an established popular favourite. Yet on its introduction some five-and-thirty years ago--I had then just received the plant from my lamented friend Mr. G. U. Skinner--its first feeble attempts to flower left such an impression of its insignificance upon my mind, that I churlishly refused it a place among the magnates of its family in "The Orchidaceæ of Mexico and Guatemala" on which I was then engaged! But greater discrimination in the treatment of our plants--in other words the recognition of the system of "Cool-Orchid-growing"--has led to a more just appreciation of its merits.

NOTES.

The mention of the illustrious traveller's name reminds me of the obligations under which he laid me when I first visited Berlin, in the spring of 1836; for, young as I was, he deigned to pour into my delighted ears all the stores of Orchid-lore collected during his memorable wanderings among the Andes of New Grenada and Peru. Here, he said, the greatest store of beauteous Orchids was to be found, and we are now beginning to realize the truth of his remark.

Cool Orchids from the interior of South America, have either to be carried across the Andes, where the intense cold of the passes is often fatal to them, or to be conveyed by a tedious voyage down the great rivers, where the heat is greater than their constitution--often delicate--can endure. In this way whole importations have been lost, including, I am sorry to say, one or two cargoes of the exquisite Odontoglossum Warczewitzii (figured in Reichenbach's "Xenia") which still unhappily remains a desideratum.

As most of the Odontoglossa require to be treated in the same way, I transcribe, from the 'Guide to Cool-Orchid Growing' (Reeve, 1864), the following instructions for the culture of the genus:--"They will all succeed perfectly in a low lean-to house facing the north, the mean temperature of which need not exceed 60°. They should stand on a shelf of slate or stone, near the glass, but should always be protected from the direct rays of the sun. Constant humidity should be maintained by damping the shelves and floors, but the plants themselves will only require water in moderation, and what is given to them should pass away freely, for if it stagnates, or if the compost in which they grow becomes sodden, the roots will immediately decay. A gentle evaporation is greatly assisted by placing layers of moss--to be kept damp of course--on the shelves whereon the plants stand. Odontoglossa cannot endure wooden blocks, but will thrive in a compost of which one-half consists of small broken potsherds, the remainder being a mixture of shredded sphagnum (dusted with fine sand) and fibrous peat. About one-third of the entire depth of the pots may be filled with this mixture, the other two-thirds containing nothing but large pieces of broken pots, so as to admit as much air as possible to the roots. The pots in which the plants are grown should stand on other pots (inverted) placed in saucers of water, in order to secure humidity and protect them from wood-lice. Nearly all the species flower during the winter or spring months, a circumstance that greatly enhances their value. Many, e. g. O. pulchellum, are deliciously fragrant, and the flowers of nearly all the species remain in perfection for weeks, whether left on the plants or cut for bouquets. In so vast a genus we shall, no doubt, meet with many idiosyncrasies, but nine-tenths of the species will flourish under the treatment indicated above, and which may be regarded as suitable to the majority of cool Orchids. Most Odontoglossa are, like the Masdevallias, very impatient of the knife, and cannot therefore be rapidly multiplied. They have also a peculiar aversion to fumigation by tobacco, which causes their leaves to fall off."

The idea that Cuitlauzina pendula might possibly be identical with Odontoglossum citrosmum had more than once occurred to myself, but Lexarza's character of the flower-scape,--which he described as "bracteis destitutus,"--had always proved an insuperable difficulty. It seems, however, that the scapes of the other Odontoglossa that he met with happened to be entirely clothed with large inflated bracts; our present plant therefore, in which they occur only at long intervals and are exceedingly minute, may in comparison be said to be almost "destitute" of them.

Mr. Skinner has lately received from Guatemala some magnificent specimens of O. grande, which are incorporated with masses of Fern and other shade-loving plants. Cultivators might make a good practical use of the well-known maxim "noscitur a sociis" in this case.

I copy Sir Robert's description of the locality in which these plants were found, in the hope that some collector may be induced to visit so interesting a region:--"The Diothonea was met with on the high mountain-chain between the sixty-fifth and sixty-sixth meridian and the fourth parallel of latitude, at an elevation of 6-7000 feet above the sea-level. The summits of those elevations are thickly covered with two species of Lichen, the white colour of which conveys the supposition that the ground is covered with snow. The thermometer stood frequently in the morning at 57° F., which, connected with the snow-white Lichens, powerfully reminded us of a winter landscape. Indeed, the stunted trees, with grey tortuous branches, would have assisted to make the picture complete, if numerous Orchidaceæ, conjointly with green Mosses, had not clothed them. Indeed, it was the Orchidaceæ alone that gave the vegetation a tropical aspect.... We discovered the Maxillaria near Mount Maravaca."--Lindl. Sert. Orch. sub t. xl.