ACERAS. OPHRYS. 319 



high. L. oblong, obtuse ; upper lanceolate, acute. Spike elon- 

 gated, cylindrical, dense. Bracts 3-veined. Fl. small, yellowish- 

 white, fragrant. Mountain pastures. P. VI. VII. 



3. ACERAS R. Br. 



1. A. anthropophora (R. Br.) ; lip 3-parted, segments linear- 

 filiform, middle one bifid and often with an intermediate tooth. 

 E, B. 29. R. xiii. 357- Root-knobs ovate. Height 812 in. 

 Spike long, lax. Fl. greenish-yellow. Sep. ovate, acute, con- 

 nivent, margined with purple, including the linear-lanceolate ob- 

 tuse petals. Dry chalky places. P. VI. E. 



4. HABENARIA R. Br. Frog Orchis. 

 * Spur very short, usually inflated. CGELOGLOSSUM Hartm. 



1. H. viridis (R. Br.); spur 2-lobed, lip linear fiat 3-pointed 

 middle point the shortest. Orchis Sm., E. B. 94. R. xiii. 434. 

 Peristylus Lindl. Lip with 3 tubercles at its base, 1 central, 2 

 lateral. Stigma oblong, slightly emarginate above. Glands of 

 the pollen-masses connected by an elevated transverse line. Sep. 

 and pet. connivent. Root-knobs palmate. Fl. green, lip browner. 

 St. 68 in. high. Pastures. P. VI. VII. Frog Orchis. 



** Spur slender. PLATANTHERA Rich. Butterfly Orchis. 



2. H. bifolia (R. Br.) ; spur twice as long as the germen, lip 

 linear entire, pet. connivent obtuse, anth. oblong truncate its cells 

 parallel. E. B. S. 2806. R. xiii. 429. About a foot high. Root- 

 1. usually 2, elliptical. Stem-1. small, lanceolate, resembling the 

 bracts. Spike slender. Fl. white. Central line between the 

 cells of the anther a furrow in front and a keel behind. Stigma 

 truncate, emarginate with pointed lobes. Heathy places. P. 

 VI. VII. 



3. H. chlorantha (Bab.); spur twice as long as the germen, 

 lip linear entire, pet. connivent obtuse, anth. truncate its cells 

 twice as distant at the base as at the top. Orchis bifolia Sm., 

 E. B. 22. R. xiii. 430. Usually taller and stouter than the pre- 

 ceding. Spike usually lax, but sometimes dense. Fl. larger. 

 Central line between the cells of the anther a prominent ridge 

 in front and a groove behind. Space between the bases of the 

 anth. -cells usually, not always, spread open. Stigma very broad, 

 slightly pointed in the middle. Moist woods and thickets. P. 

 V. VI. 



5. OPHRYS Linn. 



1. 0. apifera (Huds.) ; lip tumid 5-lobed, 2 lower lobes pro- 

 minent and with a hairy base, 2 intermediate reflexed truncate, 



