POGONU. CXL. ORCHIDACELE. 535 



/?. (O. incisa. Wittd.) Lateral petals subdentate, terminal one incisely den- 

 tate i spur subulate. 



18. O. LEUCOPHJEA. Nutt. Wkitc-jloiKered or Prairie Orchis. 



St. leafy ; Ivs. lanceolate, tapering to a narrow, obtuse point, channeled ; 

 bracts shorter than the ovaries ; roc. oblong ; sep. roundish-oblong, acutish ; 

 ! a! eral petals obovate, denticulate; 'lip 3-parted, flabelliform, segments deeply 

 ihnbriate ; spur subulate-clavate, curved, twice as long as the ovary. Wet 

 prairies, Ohio, Ind. ! 111. Stem 1 3f high. Leaves 2 6' long. Raceme about 

 i-i-flowered. Sepals and spur yellowish, petals white. Ovary curved, 1' long. 



19. O. GRANDIFL6RA. Bw. (Habenaria. Torr. Platanthera fimbriata. 

 Lindl.} Large-flowering Orchis. Lower Ivs. oblong, oval, obtuse, upper 



ones very narrow ; bracts shorter than the ovary; roc. oblong; Up dependent, 

 twice as long as the petals, 3-parted, the segments -cuneiform and fimbriate, the 

 middle one largest, with connivent fimbrise ; lateral pet. fimbriate ; spur ascend- 

 i;:p, clavate, longer than the ovary. A superb plant, considered the most beau- 

 tiliil of the genus, in wet meadows, N. H. ! Can. Stem 2 3f high, thick, hol- 

 low, with several sheathing bracts at base. Leaves 2 or 3 principal ones, 4 7 

 by 12', upper ones linear, an inch or two long. Flowers very large, purple, 

 in a terminal raceme, 3 6' long. Middle seg. of the lip nearly semicircular, 

 twice as long as the lateral ones. June. 



SECTION 3. Pollen powdery, or consisting of loosely cohering 



granules. 



8. ARETHUSA. Swtz. 

 Arethusa was a fabulous nymph of Diana, who was transformed into a fountain. 



Perianth with its segments cohering at base ; lip spurless, adnate 

 to the column at base, deflected at the end and bearded inside j pollen 

 angular. Small plants, inhabiting wet places. 

 A. BULBOSA. BuJbous Arethusa. 



Leafless; rt. producing a globular tuber; scape sheathed, 1-flowered. 

 This beautiful and interesting plant is found only in wet meadows and swamps, 

 Can. to Va. Stem 6 12' high, invested with about 3, long, loose sheathes with 

 lanceolate points, the upper ones rarely at length produced into a short, linear- 

 spatulate leaf. At the top is a single, large, fragrant flower of a rich purple 

 color. A little below the base of the flower is a small spathe of 2 unequal 

 bracts. June. 



9. POGONIA. Brown. 



GT. ircoywv, beard ; in allusion to the bearded lip. 



Perianth with its leaflets distinct ; lip sessile or unguiculate, 

 cucullate. bearded inside ; pollen farinaceous. 



1. P. OPHIOGLOSSOIDES. Br. (Arethusa. Linn.} 



Rt. fibrous ; st. furnished with an oval-lanceolate leaf and a foliaceous 

 bract near the flower ; Up fimbriate. An interesting plant, much taller than 

 the bulbous Arethusa, found in swamps and muddy shores, Can., N. Eng. to 

 Car. and Ky. The stem is very slender, 9 16' high, with 2 remote leaves, the 

 one placed about midway, 2 3' long, lanceolate, acute, sheathing at the base; 

 the other (a bract ?) much smaller, situated near the flower. Flower large, 

 nodding, pale purple. Lip long as petals and sepals (f '). June. 



2. P. VERTICILLATA. Nutt. (Arethusa. WiUd.} 



Lvs. 5, oblong-lanceolate, verticillate ; fls. solitary, the 3 outer petals very 

 long, linear, inner ones shorter, lanceolate, obtuse ; //j/3-lobed, the middle lobes 

 undulate. Swamps. Stem 8 12' high, with a whorl of leaves near the tcp 

 and a flower 12' above it. Leaves !' long, as wide, abruptly acuminate. 

 The flower is remarkable for its sepals being about 2' long, very narrow, and 

 of a greenish-brown color. Lip crested in the middle. July. 



3. P. PENDULA. Lindl. (Triphora. Nutt. Arethusa. WUld.) 



Rt. tuberous ; si. leafy, about 3-flowered at the top ; Ivs. clasping, ovate, 

 alternate ; fls. axillary, nodding ; Up entire, scabrous, not bearded ; Jr. pendu" 



