130 ORCHIDACEJE. 



ORDER CV. ORCHIDACE-ffi. 



Perennial herbs, with perfect irregular 3-merous flowers, an inferior 1-celled 

 ovary with 3 parietal placentae and very numerous ovules, 1 or 2 gynandrous 

 stamens, and waxy or more or less coherent pollen. Flowers usually inverted 

 by torsion of the ovary, the sepals and the two lateral petals similar, the superior 

 petal (apparently inferior) dissimilar and called the lip. Stamens coherent with the 

 style, forming the column, with usually only the anther opposite to the lower sepal 

 perfect and two rudimentary lateral ones (in Cypripedium the lateral ones perfect and 

 the third sterile) ; anthers 2-celled : pollen more or less coherent in 1 to 4 masses, 

 rarely wholly granular. Stigma oblique and concave, mostly viscous, the upper 

 margin often produced into an erect beak. Capsule coriaceous or membranaceous, 

 dehiscing usually by 3 placentiferous valves, which separate from the persistent 

 midveins of the carpels. Seeds very numerous and minute, scobiform (like saw- 

 dust), without albumen. Stems simple or scape-like ; leaves alternate, sheathing, 

 parallel-veined, sometimes scale-like. Roots often tuberous or thickened, some- 

 times parasitic. 



A very large order, except Graminece the largest among Monocotyledons, occurring every- 

 where, and especially abundant in tropical America, though sparingly represented in the United 

 States, and still more so on the Pacific coast. 



TRIBE I. MALAXIDEJ1. Anther one, terminal and resting like a lid upon the column, 

 deciduous. Pollen-masses 4, smooth and waxy. Our species without green herbage (a 

 single green radical leaf in Aplcctrum and Calypso). Flowers pedicellate. 



1. Calypso. Scape 1 -flowered, from a solid bulb. Lip saccate. Column broadly winged. Pol- 



len-masses sessile on a large gland. 



2. Corallorhiza. Flowers racemose, spurred or gibbous at base. Lip expanded or concave, 



bilamellate-crested. Column semiterete. Pollen-masses free, without glands. Hoots 

 branched, coralline. 



3. Aplectrum. Flowers racemose, not spurred nor gibbous. Lip expanded, deeply 3-lobed, 



3-laniellate. Column nearly terete. Pollen-masses in distinct pairs, without glands. 

 Rootstock bearing annually a solid bulb and a single large green leaf. 



TRIBE II. OPHRYDE^E. Anther one, connate with the column and persistent upon its face 

 immediately above the stigma. Pollen-masses 2, of coarse grains united by an elastic 

 web, each mass attached at base by a stalk to a viscid gland. Stems mostly leafy and 

 flowers spicate or racemose. 



4. Habenaria. Flowers numerous, white or greenish. Lip flat, spurred. Glands exposed. 



TRIBE III. NEOTTIE^E. Anther one, erect and sessile or nearly so upon the top of the 

 column and more or less covering and decimate upon the back of the stigma, persistent. 

 Pollen-masses 2 or 4, of loosely cohering granules, becoming attached by their upper ends 

 to a viscid gland on the beak of the stigrna (or remaining free in C'cphalanthera). Our 

 species without spurs, mostly somewhat pubescent. 



5. Spiranthes. Perianth oblique upon the ovary, the sepals and petals connivent : lip oblong, 



embracing the column, with 2 callosities at base. Flowers small, white or greenish, 

 1 - 3-ranked in a twisted spike. Stems leafy below, from tuberous-fascicled roots. 



6. Goodyera. Like Spiranthes, but lip saccate, entire, without callosities and free from the 



column. Leaves all radical, white-reticulated. 



7. Listera. Perianth spreading. Lip flat, 2-lobed. Stem low, from a fibrous root, with a pair 



of sessile leaves in the middle. Flowers small. 



8. Epipactis. Perianth spreading and ovary recurved. Lip somewhat jointed in the middle, 



concave and auriculate at base, dilated above. Column short. Anther sessile behind 

 the beaked stigma. Stem leafy, stout. 



9. Cephalanthera. Flowers erect, the perianth more connivent. Column slender. Anther 



shortly stipitate and stigma beakless. Otherwise as Epipactis, but our species without 

 green herbage. 



