(Greek, swan's neck, referring to the shape of the column). Orchidaceae. Epiphytic orchids, requiring warmhouse treatment when growing.

Pseudobulbs fusiform: leaves plicate: flowers of 2 sexes, the perianth alike, the lip entire, or that of the staminate very different, with the sepals and petals narrower, the lip clawed and with finger-like projections from the side, the column much elongated and arched; pol-linia 2. Both sexes may be produced in the same plant. A third form of flower, usually perfect, occasionally appears; this is intermediate between the others. - About a dozen species of tropical Amer.

A. Perianth alike in both sexes; lip entire.

Chlorochilon

Klotzsch. Pseudobulbs 5-7 in. tall: leaves lanceolate: raceme erect, 2- or 3-flowered; flowers 4-6 in. across; sepals and petals yellowish green, acute, the lateral sepals broader than the dorsal; lip obovate or elliptic, acute, a dark green depression near the triangular erect callus. Venezuela. G.C.III. 3:145. I.H. 35:65. R. 1:39. J.H. III. 35:285. Gn. 49, p. 403; 51:172.

Ventricosum

Batem. Pseudobulbs 8-10 in. tall: leaves lanceolate: raceme drooping, 4-6-flowered; flowers 4-5 in. across; sepals and petals yellowish green, acute, the petals broader than the sepals; lip white, cordate, acuminate, clawed, a black callus at the junction of the claw with the lip. Guatemala.

aa. Perianth differing in the sexes; lip with finger-like lateral projections.

Aureum

Lindl. Male racemes pendulous, 8-12-flowered; flowers 2-3 in. across, yellow, red-spotted; sepals and petals similar, the former spreading, the latter reflexed; Up clawed, the dilated middle giving rise to a number of projections, forked at the end. Cent. Amer. J.F. 3:264.

Pentadactylon

Lindl. Male racemes usually pendulous, many-flowered; sepals and petals greenish yellow barred with brown; lip white, red-spotted, with 5 finger-like projections; female racemes erect, few-fid.; sepals and petals broader than in the male flowers, spotted; lip ovate, entire. Brazil. B.R. 29:22. J.H. III. 62: 305. O.R. 8:312.

Peruviana

Rolf e. Male racemes pendulous, many-flowered; sepals and petals light green, copiously brown-spotted; Up, with its projections, white. Peru. Lind. 7:301.

C. densiflorum, Rolfe. Male racemes pendulous, many-flowered, the flowers greenish with purple blotches; female racemes short, erect, 2-flowered, the sepals and petals green, the lip ivory-white. Colombia. O.R. 17:204; 20:331. B.M. 8268. - C. maculatum, Lindl. Male racemes pendulous, the sepals and petals light yellowish green, spotted with red-purple, the lip white. Mex. 0.1910:104. O.R. 17:273; 20:315.

George V. Nash.