Even with this additional information, however, it 
seems advisable to consider this concept among the ob- 
scure species. 
Odontoglossum mystacinum (Lindl.) Lindley 
Fol. Orch. Odontoglossum (1852) 6, no. 14. 
Cyrtochilum mystacinum Lindley in Bot. Reg. 24 
(1838) Mise. 30, no. 38; in Bot. Reg. 25 (1839) t. 62. 
Odontoglossum rigidum Lindley in Benth. Pl. Hartw. 
(1844) 152; Fol. Orch. Odontoglossum (1852) 7, no. 
Ve 
Judging by an excellent photograph of the type of 
Odontoglossum rigidum from the Lindley Herbarium, 
this concept cannot reasonably be separated from the 
species depicted as Cyrtochilum mystacinum in the Botan- 
ical Register 25, t. 62. A slight difference is that the 
pseudobulb of the latter concept is represented as uni- 
foliate, whereas that of O. rigidum is bifoliate with very 
unequal leaves. Recent Peruvian collections which are 
referable to this concept have sometimes unifoliate and 
sometimes bifoliate pseudobulbs. Although O. rigidum 
has a more branched and fractiflex panicle than that of 
Cyrtochilum mystacinum, the plate was obviously drawn 
from an immature specimen. A minor difference is that 
the wings of the column in the latter concept are rather 
broad and multifid, whereas they are drawn as rather 
narrow and serrate in O. rigidum. 
Both species, however, have similar pseudobulbs and 
yellow flowers with almost identical segments. The se- 
pals are lanceolate, the petals ovate-lanceolate and the 
lip pandurate-obovate. Moreover, the column wings are 
not easily seen in the specimens examined and appear to 
be variable. 
This species appears to be limited to Peru, Ecuador, 
and perhaps Bolivia. 
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