PL. CCLXXIV. 
ONCIDIUM LEOPOLDIANUM ROLFE. 
KING LEOPOLD’S ONCIDIUM. 
ONCIDIUM Swartz. Perigonii explanati foliola exteriora undulata, lateralia libéra vel sub labello connata ; 
interiora conformia. Labellum maximum, gynostemati continuum, ecalcaratum, lobatum, basi tuberculatum vel cristatum. 
Gynostema erectum, semiteres, apice utrinque alatum; anthera incomplète bilocularis, rostello abbreviato vel elongato, 
rostrata. Pollinia 2, postice sulcata ; caudicula plana ; glandula oblonga. 
Herbae americanae tropicae saepius pseudobulbosae ; foliis coriaceis, planis, complicatis, triquetris vel tere- 
tibus; scapis paniculatis, vaginatis, rariusve simplicibus ; floribus speciosis, ut plurimum luteis, saepe maculatis, 
rarius albis. 
R. Brown in Ait. Hort. Kew. II, 5,215. — Kunth, Nov. Gen. et Sp. tab. 79-82. — Endl. Gen. Plant., 1460. 
Oncidium Leopoldianum. Habitu O. macranthi Lindl., pseudobulbis longioribus et angustioribus scapo valde 
elongato ramoso multifloro, bracteis late ovatis acutis 7-8 cm. longis, floribus mediocribus, sepalis breviter ungui- 
culatis, sepalo postico late elliptico obtuso 1,2 cm. lato, sepalis lateralibus elliptico-ovatis obtusis 1-3 cm. latis, 
petalis elliptico-ovatis subacutis sepalis paullo parvioribus, labello carnoso trulliformi leviter trilobo subacuto, 1,5 cm. 
longo, 1 cm. lato, lobis lateralibus rotundatis, callo trilamellato, lamello medio paullo majori, columna brevi, 
alis carnosis rotundatis. 
Oncidium Leopoldianum Rolfe, in Gard. Chron., 1890, pars II, p. 556.— joùrn. des Orch., vol. I, p. 293. 
his is a noble and very handsome species, recently introduced by Messrs 
Linden, L’Horticulture Internationale, Parc Léopold, Brussels. It 
belongs to the Cyrtochilum section, to the group defined by Lindley, 
in his Folia Orchidacea , as Microchila exaurita. It is closely allied to O. corynephomm , 
Lindl., which, however, is readily distinguished by its broadly rounded lip, and 
other characters. 
It is dedicated to His Majesty Léopold II, King of the Belgians. 
Oncidium Leopoldianum , like many of its allies, has a very long scape. It is 
said to attain a height of several métrés, and to bear as many as three hundred 
flowers. The two branches of the panicle before me contain fourteen dried flowers, 
and undoubtedly indicate a species of great beauty. In this condition they measure 
1 -§- inches in diameter, and are very compactly arranged on the raceme. The 
colours are very beautiful and afford a decided contrast with the majority of 
Oncidiums, in which yellows and browns predominate. The sepals and petals are 
white, each with a purple dise, the lip being of a violet-purple hue, with the crest 
and part of the column yellow. When it becomes established, it will doubtless 
prove a great acquisition. 
Its nearest ally, O. corynephomm Lindl., has evidently similar colours. It 
is only known by dried specimens, collected by Matthews, in Peru, and it is 
strange that so fine a species should still remain unknown in gardens. Specimens 
may hâve been sent and failed to reach their destination alive, for it is well known 
