306 OKCHIDACEAE (ORCHIS FAMILY) 



ARTIFICIAL KEY TO GENERA 



a. Two fertile anthers ; lip an inflated sac 1. CYPRIPEDIUM. 



a. One fertile anther &. 



6. Flowers with a distinct slender spur (this at least 2 mm. long). 

 Leaves present at flowering time. 

 Caudicles of pollinia divergent, not contained in a special pouch or 



bursicule 3. HABENARIA 



Caudicles of pollinia convergent, contained in a special pouch or 



bursicule 2. ORCHIS. 



Leaves absent at flowering time 17. TIPULARIA. 



&. Flowers without a conspicuous spur, the lip sometimes saccate c. 

 c. Leaves one or more (in Spiranthes, Arethusa, and Aplectrum some- 

 times absent or inconspicuous at flowering time); plant green d. 

 d. Perianth at least 15 mm. across ; sepals and petals more or less 



spreading, not strongly recurved e. 

 e. Leaves linear to linear-lanceolate, grass-like, sheathing the scape 



near the base. 



Flowers several, resupinate, with one floral bract ... 5. CALOPOGON. 

 Flowers solitary, rarely 2, not resupinate, with 2 floral bracts, 



one posterior, the other anterior, subtending the ovary . 6. ARETHUSA. 

 . Leaves elliptic-oblong, ovate, or cordate, sometimes whorled. 



Lip saccate, bearded 15. CALYPSO. 



Lip not saccate, with a longitudinal more or less tuberculate 



crest or beard 4. POGONIA. 



Lip saccate, not bearded 7. SERAPIAS. 



d. Perianth less than 15 mm. across ; sepals and petals connivent or 



spreading. 



Petals joined to the upper sepal but not coalescent with it. 



Lip saccate at base, devoid of basal callosities ; leaves variegated 9. EPIPACTIS. 

 Lip not distinctly saccate, with a horn-like callosity within on 



each side at base ; leaves not variegated .... 8. SPIRANTHES. 

 Petals and sepals free. 

 Petals filiform or linear, less than 2 mm. broad. 



Leaf solitary 13. MICROSTYLIS. 



Leaves 2, near the middle of the stem 10. LISTEKA. 



Leaves 2, basal ; lip not pointed 14. LIPARIS. 



Leaves basal ; lip pointed 12. MALAXIS. 



Petals not filiform, at least 2 mm. broad 16. APLECTRUM. 



C. Leaves wanting ; scaly saprophytes with yellowish or purplish stems. 



Lip with a callus on each side of the mid-nerve at base . . .11. CORALLORRHIZA. 

 Lip with 5 or 6 longitudinal crests 18. HEXALECTRIS. 



1. CYPRIPEDIUM L. LADY'S SLIPPER. MOCCASIN FLOWER 



Sepals spreading, all three distinct or in most cases two of them united into 

 one under the inflated sac-like lip. Petals mostly spreading, linear or oblong. 

 Column declined, on each side a fertile stamen with its short filament bearing 

 a 2-celled anther ; pollen loose and pulpy or powdery-granular, the face of the 

 anther converted into a viscid film ; on the upper side of the column a dilated 

 petaloid, but thickish staminode, or infertile stamen ; stigma terminal, obscurely 

 3-lobed, moist and roughish. Roots coarsely fibrous. Leaves many-nerved and 

 plaited, sheathing at the base. Stems pubescent. Flowers solitary or few, 

 large and showy. (Name incorrectly Latinized from Etta-pis, Venus, and wtdiXov, 

 a shoe, therefore by some authors spelled Cypripedilum.) 

 1. The three sepals separate. 



1. C. arietinum R. Br. (RAM'S HEAD L.) Stem slender, 15-30 cm. high ; 

 leaves 3 or 4, elliptic-lanceolate, nearly glabrous ; upper sepal ovate-lanceolate, 

 acute, lower sepals and the petals linear, similar, madder-purple, 1.5-2 cm. long, 

 exceeding the whitish crimson-veined lip, which is silky pubescent within. 

 (Criosanthes borealis Raf. ) Swamps and rich woods, rare and local, Que. 

 to Man., s. to Me., Mass., N. Y., and Minn. May, June. (China.) 



2. The two lower sepals united. 

 * Stem elongated, leafy to the top, 1-3-fiowered ; lip slipper-shaped, not fissured 



in front, but with a rounded open orifice. 



- Sepals and linear twisted petals acute, longer than the lip. 



+* Lip yellow. 



2. C. parvifl6rum Salisb. (SMALLER YELLOW L.) Stem 19-60 cm. high; 

 petals and sepals greenish, much suffused with madder-purple, 3-5 cm. long ; 



