412 Key to the System of 



labellum, brownish-green ; upper calyx-lobe and petals 

 of nearly equal length, light-yellow, the spots large, 

 generally two on the upper calyx-lobe and labellum ; 

 paired petals with short stalk-like base ; middle lobe of 

 the labellum rather acute, without prominent longitudinal 

 narrow elevations towards the base, much' exceeding the 

 short lateral lobes ; fruit rather slender. 



D. sulplrurea. 



Upper calyx-lobe and petals in part minutely dotted. 



Tubers thick ; basal leaves few or several, from broad- to 

 narrow -linear, often rather short ; upper leaves two or 

 three, very much abbreviated or bract-like ; flowers few or 

 two, seldom one, the lower on rather long stalklets ; lower 

 calyx-lobes greenish or somewhat brownish, little longer 

 than the labellum ; paired petals yellow, acute, narrowed 

 into a very short stalk-like base ; labellum with two 

 narrow prominent longitudinal elevations towards the 

 base, these beset with very minute hairlets ; its middle 

 lobe quite acute, downward dilated, very much exceeding 

 the minute lateral lobes ; fruit rather slender. 



D. peduncnlata. 



ORTHOCERAS. 



1785. Paired calyx-lobes much extending beyond the other 

 parts of the flower. 



Somewhat tall ; longest leaves at and towards the stem- 

 base approximated ; flowers rather distant, comparatively 

 large ; bracts conspicuous ; lateral lobes of the labellum 

 quite short ; fruit oblique-ellipsoid. O. strictum. 



CORYSANTHES. 



1786. Upper-calyx lobe gradually narrowed to the base. 



Quite dwarf ; leaf green also underneath ; flower of con- 

 siderable size, purplish-dark except part of the outer side 

 of the upper calyx-lobe ; labellum conspicuously contracted 

 towards the base, slightly or shortly denticular-fringed, its 

 upper portion dilated, curved forward and streaked ; fruit 

 slender- ellipsoid. C. pruinosa, 



LYFERANTHUS. 



1787. Radical leaf present at the flowering time. 



Somewhat dwarf, but robust, turning black in drying ; basal 

 leaf rather large, from ovate to orbicular-cordate, of thick 

 texture, sessile ; flowers large, several, few or two, largely 

 reddish, but to some extent colorless and transparent ; 



