993 



Platanthera bifolia. 



tion of the cells appearing to form 

 a groove in front; cells of the an- 

 ther rising almost perpendicularly, 

 parallel throughout. 



Stigma scarcely one-third the 

 size it is in P. chlorantha, its 

 superior posterior margin much 

 thickened into a prominent, gland- 

 like projection in the centre, oc- 

 cupying nearly the whole space 

 between the lower ends of the an- 

 ther-cells. 



Lateral petals but little di- 

 minished in width, or nearly as 

 broad throughout as their rounded 

 bases, rising almost perpendicu- 

 larly, and converging much above 

 the anther, their tips not crossing 

 or overlapping, but erect, usually 

 conjoined below their summits, the 

 latter in that case spreading or 

 diverging, sometimes simply ap- 

 proximate and erect (not touching 

 or conjoined). Inferior petal or 

 lip shorter and broader than in 

 P. chlorantha, and in general 

 straighter, but little (or often not 

 at all) decurved. 



Lateral sepals (usually) more Lateral sep>als spreading hori- 

 deflexed than in P. bifolia. zontally, seldom, or but little de- 



flexed, except at the tips. 



Platanthera chlorantha. 



ridge in front or between the cells, 

 which are widely diverging at 

 their lower ends, and obliquely 

 ascending inwards and backwards. 



Stigma very broad and concave, 

 forming a semicircular, basin-like 

 cavity ; slightly pointed in the 

 middle by a thickened glandulose 

 projection of its superior margin. 



Lateral petals narrow or at- 

 tenuated almost from their round- 

 ed bases, curved over the stigma, 

 their tips crossing or overlying, 

 and forming an arch just above 

 the anther, occasionally merely 

 approximate or conjoined at their 

 summits. Inferior petal (lip) 

 longer and narrower than in P. 

 bifolia, mostly curved downwards 

 and backwards. 



Spur very strongly keeled and 

 compressed, visibly dilated or sub- 

 clavate at the extremity, and most- 

 ly much curved downwards; twice 

 or thrice as thick as in P. bifolia, 

 Vol. iit. 



Spur keeled and compressed, 

 filiform and subcylindrical, or of 

 equal thickness throughout, or 

 very nearly so, extremely slender, 

 and usually straighter than in P. 

 6 M 



