246 PBACTIOAL BOTANY. 



764. Leafless, tawny, or brownish-purple herbs, with 

 scaly scapes, rarely with a root-leaf. Flowers spiked or 

 racemed 765 



Herbs green, and with leaves 767 



765. Lip concave, not hooded. Pollen-masses 4 766 



Lip hooded, jointed, crested along the upper face, 



often 3-lobed. Column half-cylindric. Pollen masses 8, in 

 pairs, with a stalk to each pair. Bletia aphylla, Nutt. 



766. Lip sessile, with 2 projecting ridges on the face be- 

 low, slightly adherent at the base to the column, and often 

 with a short spur, which is adnate to the summit of the 

 ovary, lihizome much branched and toothed, coral-like. 



Corallorhiza, Haller. 



Lip short-clawed, 3-lobed, free, the palate 3-ridged. 



Not any vestige of a spur. Radical leaf, appearing late in 



the season, petioled, elliptic or ovate, large, 3-5 inches long. 



Root of 2 or more tubers, connected by thread-like fibres. 



Aplectrum hyemale, Nutt. 



767. Lip sac-like, inflated, 3-lobed at the apex, middle 

 lobe bearded above and 2-pointed underneath, near the end. 

 Column broadly winged, petal-like. Scape 1-leafed, l-flow- 

 ered, from a corm. Flower large, whitish, variegated with 

 purple and yellow. Calypso Iborealis, Salisb. 



Lip not sac-like 768 



768. Anther dorsal (attached to the back of the column). 



769 



Anther terminal (fixed to the apex) 771 



760. Lip 2-cleft, usually drooping. Stigma with a 



rounded beak. Stem with a pair of opposite, ovate leaves in 



the middle. Flowers small, greenish, or brownish-purple, 



spiked or racemed. Listera. 



Lip entire 770 



770. Lip free from the column, strap-pointed. Pollen- 

 masses elastic. Root-stock bearing a tuft of ovate petioled 

 leaves next the ground. Scape, spike, and small, greenish- 

 white flowers glandular-downy. Goodyera, R. Br. 

 Lip embracing the column, pointless, channelled. 

 Lateral outer sepals decurrent on the ovary, covering the 



