PROMENÆA CITRINA. [Plate 7.] Native of Brazil.

PROMENÆA CITRINA. [Plate 7.] Native of Brazil.

Epiphytal. Pseudobulbs small, ovate, tetragonal. Leaves three to four inches in length, oblong-ligulate, acute, tapering below into a narrow petiole, growing two together at the apex of the pseudobulb, of a pale green colour. Scapes two to three inches long, bearing largish ovate bracts in the upper part, and smaller bracts below, and terminated by a solitary deep yellow showy flower, measuring about an inch and a half across; sepals obovate, acute, concave or curving forwards at the tip, bright yellow; petals yellow, also converging, similar to the sepals in size, form, and colouring; lip larger and broader than the sepals and petals, spreading, three-lobed, the two lateral lobes erect, oblong obtuse, rising up on each side of the column, yellow spotted with red on the inner face, the front lobe plane, obovate, apiculate, unspotted yellow, with a prominent crest at its base. Column erect, semi-terete, incurved, stained in the front with brownish red.

Promenæa citrina, Don, Hortus Cantabrigiensis, ed. 13, 720 (1845); London, Hortus Britannicus Supp. 618 (1850); Williams, Orchid Growers’ Manual, ed. 4, 253, ed. 5, 281; Rand, Orchids, 377.

Maxillaria citrina, Lyons, Treatise on Orchidaceous Plants, 176.

Promenæa is a small genus of Orchids which was separated from Maxillaria about forty years ago (1843) by Lindley, who at the same time also dissociated from it the plants respectively referred to Warrea, Paphinia, Lycaste, and Scuticaria. Later on Reichenbach classed Promenæa as a section of Zygopetalum. Dr. Lindley distinguished the group of species which he referred to Promenæa, and which he regarded as fully entitled to generic rank, by the following peculiar features, namely, their spreading sepals, their three-lobed lip, crested or tuberculate at the base, their short semi-terete column, and their ovate glandule with four, that is two double, sessile pollen masses. The species then proposed were P. stapelioides, P. xanthina, P. lentiginosa, P. Rollissonii, and P. graminea. To these Reichenbach added P. guttata in 1856, and P. microptera in 1881. Neither of these authorities, so far as we can trace, refer to P. citrina; but, according to Don and Loudon, the plant was introduced to our gardens in 1840, though they attribute to it the erroneous habitat of Mexico. Our good friend, Professor Reichenbach, suggests that it is a garden name, sometimes applied to P. Rollissonii and sometimes to P. guttata; but it has long been recognised as a distinct plant by English and Continental Orchid growers, and is certainly different from the P. Rollissonii figured 15 by Dr. Lindley; nor does it correspond with the description of P. guttata, so far as the materials at hand enable us to judge.

This, it will be seen, is a very neat-growing plant, the small tetragonal pseudobulbs slowly creeping over the surface of the blocks on which the plants are grown. It is, moreover, of small stature, the leaves, which grow in pairs from the top of the pseudobulbs, rarely exceeding three or four inches in height, and the flower-scapes attaining even less elevation. The flowers, which are rather large for so small a plant, being of a rich and brilliant colour, become rather effective; and though, of course, they do not compare at all in gorgeous beauty with those of many of the larger-flowered Orchids, they are by no means to be despised even from the decorative point of View; indeed, when grown on a block, as represented in the accompanying Plate, and suspended from the roof of the house, the plant forms a very pretty and distinct object, occupying, as it does, but a small space in which it displays much beauty and attractiveness. The bright orange-yellow flowers are, moreover, very freely produced, and if kept dry, continue for a long time in a fresh and pleasing condition.

There is another species of the same habit, Promenæa stapelioides, which comes into bloom about the same time as this, and in which the flowers are spotted with dark purple, so that they appear to be nearly black. The contrast of these two when grown and flowered on the same block is very effective. In the noble collection of Sir Trevor Lawrence, Bart., M.P., we saw a large pan-full of P. citrina growing freely, which had a very beautiful appearance, but we prefer to see the plant grown on a block, as in this manner the flowers hang downwards, and are shown off to much greater advantage. There are certain varieties to be occasionally met with, in which the flowers are without spots on the lip, but those which have this latter peculiarity are to be preferred, as the two colours afford a pleasant relief.

Fibrous peat and sphagnum moss seem to suit the plant well when it is grown in either pots or pans; but when cultivated on blocks of wood, a little sphagnum moss only about its roots will be quite sufficient, though if grown in this latter way it requires a more liberal and more frequent supply of water, in order to keep the roots moist. We find the Cattleya-house to suit it best, and we grow it suspended against a wall at the end of the house, where it gets syringed in warm weather. The manner in which its blooms are produced may be seen from our Illustration, which is an excellent representation of the habit of the plant, not only as regards its general manner of growth, but also of its mode of flowering.

PL. 8. CYPRIPEDIUM STONEI.

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