7. Ponthieva R. Br. 



In this genus there are 25 species that are found in the warmer regions of the 

 Western Hemisphere from southeastern Virginia to Chile, including Mexico, 

 Central America, the West Indies and South America. 



1. Ponthieva racemosa (Walt.) Mohr. Shadow-witch. Fig. 370. 



Terrestrial scapose herb with fleshy or somewhat fibrous roots, usually about 

 3 dm. tall; leaves in basal rosette, oblong-elliptic to oblanceolate, obtuse, to 15 cm. 

 long and 5 cm. wide; flowers white-green, fragrant, nonresupinate in a lax terminal 

 raceme; sepals ovate to elliptic-lanceolate, spreading, to 8 mm. long and 3.5 mm. 

 wide; petals attached to the column above its base, oblique, often adherent to the 

 dorsal sepal at the apex; lip on the upper part of the flower, with its claw grown 

 to the column above its base, abruptly dilated and ascending, suborbicular, 

 saccate-concave, to 7 mm. long; capsule suberect, ellipsoid to obovoid-ellipsoid. 



Along streams in woods or about muddy sloughs and ponds in e. and s.e. Tex., 

 Sept.-Nov.; from s.e. Va., s. to Fla., w. to Tex.; also the W.I. and Latin Am. 



The noticeably oblique petals and lip forming the uppermost segment of the 

 flower are characteristic. 



8. Spiranthes Rich. Ladies' Tresses 



Coarse or delicate terrestrial herbs with clustered tuberous or rarely fibrous 

 roots; leaves various, mostly basal, broadly ovate to elliptic or narrowly linear 

 to semiterete, persistent or fugacious, reduced above to persistent sheathing bracts; 

 flowers variously colored, usually white and variously tinged or marked with 

 green, yellow, brown or lavender, sometimes brick-red, deep-crimson, yellow- 

 orange or yellow-scarlet, in a more or less spirally twisted showy or inconspicuous 

 terminal spike; sepals free; dorsal sepal and petals coherent; lateral sepals usually 

 somewhat decurrent on the ovary and gibbous at the base or extended to form a 

 mentum; lip sessile or with a short claw, with the basal portion concave and 

 embracing the column, spreading or arcuate-recurved at the apex, crisped, wavy 

 or toothed, with a minute or conspicuous callosity on each side at the base, some- 

 times ecallose; column short, terete to clavate, essentially footless or extended into 

 a long foot at the base; anther erect on the back of the column, 2-celled; poUinia 

 two, powdery-granular, narrowly obovoid, their filaments coherent to the narrow 

 viscid gland which is set in the thin beak (rostellum) terminating the column 

 (after the removal of the gland the beak is left as a 2-toothed or forked tip); cap- 

 sule erect, ellipsoid to ovoid or obovoid, sometimes 3-keeled. 



A polymorphic genus of about 200 species widely dispersed throughout the 

 North Temperate Zone and tropical Asia and America, south to Chile. 



1. Flowers forming a dense cylindrical spike, apparently in several ranks; basal 

 leaves (when present) with linear, lanceolate, oblong-elliptic or 

 oblanceolate blades, never with a distinct petiole, having the lower 

 part sheathing the stem (2) 



1. Flowers forming a loose or dense (usually spiral) single rank, often secund; 



basal leaves (when present) with ovate, oblong-elliptic, lanceolate 

 or semi-terete blades with a distinct petiole or with the lower part 

 sheathing the stem (4) 



2(1). Lip thin, panduriform in outline, deeply constricted at about the middle, 

 with the orbicular or oblong-quadrate basal portion deeply concave; 

 calli small; flowers ascending and ringent 1. S. Roinanzoffiana. 



2. Lip fleshy-thickened, only slightly or not at all constricted at about the middle, 



ovate-oblong to rhombic-ovate; calli large, prominent; flowers nod- 

 ding perceptibly (3) 



723 



