Refugium Botanicum. | [ November, 1872. 
TAB. 141. 
Tribe MALAXIDE. 
Genus PLevrorHauuis, &. Br. 
P. tonerssima, Lindl., Folia Orchidacea, II. Part ix. Pleurothallis, 
No. 182, p. 81.—Cespitosa, radicibus adventitiis filiformibus 
multiflexis densis, rhizomate prorepente validissimo, caulibus 
teretiusculis sulcatis abbreviatis, ima basi plurivaginatis, 
vagina una arctiore elongata sub folio, folio cuneato obovato 
apice obtusato minute tridentato constricto, valde valido, 
pedunculo folium longe excedente, basi spatha una legulata 
acuta ancipiti ochracea, vaginis fatuis brevibus paucis, racemo 
secundifloro disticho elongato nune subnutante, bracteis 
ochreatis apice oblique retusis uninervlis, ovariis pedicellatis 
exsertis, sepalo dorsali triangulo fornicato trinervi, tepalo 
inferiori oblongo apice simpliciter acuto seu bidentato, nervis 
duobus validis lateralibus, tepalis oblongo-triangulis trinerviis 
nunc acutis apicem versus serrulatis, labello pandurato obtuse 
acuto, lateribus baseos erectis, nervis ternis apice clavatis, 
omnibus ante apicem evanidis, columna clavato-trigona, andro- 
clini limbo vulgo tridentato, rostello triangulo deflexo, fovea 
subrotunda.—Pleurothallis racemiflora, Lindl. in Hook. Exot. 
Fl. u. t. 123! Lodd. Bot. Cab. 949! Lindl. Gen. d Sp. Orch. 
p. 6, excl. citat. Swartzianis! Flores virides demum flavo- 
virides. 

This Pleurothalliis was formerly common in German gardens, 
and is even now kept at some places. It was thought to be the 
Dendrobium racemiflorum of Swartz, which is immediately dis- 
tinguished by the petiolar base of the leaf. It was, however, only 
in 1859 that the old error was corrected by Dr. Lindley himself. 
The reason may have been that what I believe to be the solitary 
Swartzian type in German herbaria, Willdenow’s No. 16,896, was 
signed ‘‘ Humboldt.” Now the paper to which it is fastened cor- 
responds to that to which the other Swartzian types are gummed, 
and, from my sketch, I believe the plant agrees altogether with 
Swartz’s types, kept at Stockholm, just now at my side. I have 
suspected the mistake since 1846; I could, however, not make use 
of my opinions until I had more positive proofs. ‘The habitat of 
P. longissima was unknown to Dr. Lindley when he described the 
plant: “I have nowhere found wild specimens of this, and much 
