OHCHIDACE^. 233 



6. LIS'TERA, P. Br. Twayblade. 



1. L. corda'ta, E. Br. Eacemes crowded ; pedicels not 

 longer than the ovary. Lip linear, 2-eleft. Column very 

 short. — Damp cold woods. 



2. L. eonvallarioi'des, Nutt. Eacemes loose and slender : 

 pedicels longer than the ovary. Lip wedge-oblong, 2-lobed. 

 Column longer than the last. — Damp thickets. 



J. CALOPO'eoN, R. Br. Calopogon. 

 C. pulehel'lus, E. Br. Leaf linear. Scape a. foot high. 

 Flowers an inch across. — Bogs. 



8. ARETHIJ'SA, GronoT. AKETHnSA. 

 A. bulbo'sa, L. A beautiful little bog-plant, bearing a 

 single large flower (rarely 2), with the lip bearded-crested on 

 the face. 



9. POGO'MA, Jnss. POGONIA. 



P. ophloglossoi'des, Nutt. A bog-plant. Sepals and 

 petals nearly equal and alike. Eoot of thick fibres. 



10, CALYP'SO, Sallsb. Caltpso. 

 C. borea'lls, Salisb. A beautiful little plant growing in 

 mossy bogs. The lip woolly inside ; the petals and sepals 

 resembling each other, lanceolate, sharp-pointed. Column 

 winged. 



11. MICROS'TILIS, Nntt. Addeh's Hodth. 



1. M. monophyl'los, Lindl. Leaf sheathing the l)ase of 

 the stem, ovate-elliptical. Eaceme spiked, long and slen- 

 der. Lip long-pointed. — Cold swamps. 



2. M. ophloglossoi'des, Nutt. Leaf near the middle of 

 the stem , ovate, clasping. Eaceme sAorf. Lip 3-toothed. — 

 Damp woods, not so common as the last. 



12. UP'ARIS, Richard. Twayblade. 

 T- LoBS.e'IU, Eichard. Lip yellowish-green, mucronate, 

 shorter tlian the unequal petals and sepals. Leaves eilip- 

 bical-lanoeolate or oblong, keelied.^Bogs. ^^o- 



